Heating : Smart con...
 

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[Closed] Heating : Smart controllers for people who stay at home?

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I live in a house with my wife and both work from home so we are in the house most of the time. We need to heat the house to a comfortable level. Comfortable level is a vague term between 19 and 25 degrees which seems to vary with my wife's mood but we will ignore that for the moment. We seem to be unusual compared to other STWers in that we actually move from room to room during the day rather than only be sat in one place and only want to heat one room.

We are going to be replacing various radiators around the house, probably in phases, as we redecorate. We are thinking of fitting the Thermaskirt style (skirting board level) radiators to free up the wall space for less restrictions on placing furniture etc.

We currently have a timer and thermostat controlling the whole house with individual adjusters on the radiators. I prefer to adjust the thermostat or individual radiators to vary the temperature but the wife just turns up the thermostat and opens windows.

It is a fairly standard 3 bed detached house with an attic I use as an art studio. Downstairs we have a big hallway open to the second floor so any heat in there goes straight upstairs. The kitchen, living room and dining room are the ones that need the heating. The conservatory does need heating but can be cooler. Upstairs the main bedroom and the room converted to my office need heating but the spare room can be left cooler. The art studio is heated by the rising heat so can be ignored.

Does it make any sense to get Hive or other such smart heating systems in this scenario?


 
Posted : 28/10/2021 9:42 am
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use as an art studio.

woodburner, obvs

serious answer, prob not, wasn't this what TRVs were invented for?

Unless you zone off every room and somehow valve it up so that the smart controller can divert flow to the appropriate room?


 
Posted : 28/10/2021 9:46 am
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Yes, if you can shut the downstairs rooms off from the floor.

I've got 3 Wiser TRVs and a thermostat so control dining room, living room and two bedrooms plus hot water. Other rooms have old school TRVs.

It makes it easier to keep the living rooms and bedrooms cold during the day whilst I fester in my office but easy to turn on e.g. it's half term and the mother in law is visiting.


 
Posted : 28/10/2021 9:52 am
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[i]It makes it easier to keep the living rooms and bedrooms cold during the day whilst I fester in my office but easy to turn on e.g. it’s half term and the mother in law is visiting.[/i]

Sorry - possibly I wasn't clear. During the day we regularly use the kitchen, dining room, living room, office and to a lesser extent the main bedroom. It is only really the conservatory, spare bedroom and art studio that can be left colder.

That is why I don't think super computer controlled central heating would be worth it for us and was asking if I was wrong or had missed something.


 
Posted : 28/10/2021 10:00 am
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Doesn't sound it to me then


 
Posted : 28/10/2021 10:10 am
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Yes it is worth it. With rad TRV valves you can move a smart thermostat (they are magnetic so can move and get a stand to place anywhere in the home) so can be moved to the room where you are during the day so can keep the rad going in the room where you are while the TRV’s shut off the roads throughout the rest of the house. So your wife can still feel like she’s in control of the thermostat wherever she is in the house. You just need to make sure you’re managing the settings in the TRV valves.


 
Posted : 28/10/2021 10:21 am
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Yes it is worth it if you get smart TRVs. We have a Tado system which has been great. We have a schedule to only warm the bedrooms at night, only warm the office in the day and only work days, put the UFH on from 5-7am only, etc.

Think Drayton and Honeywell also do similar. It's like every radiator being its own heating zone. For us that is way more beneficial than just the hive or nest system which is still just an overall on/off for the whole house.


 
Posted : 28/10/2021 10:43 am
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Just looking at the Tado system. A new thermostat and wireless controller is £199 which is one per house. Then each radiator vale - Add-on Smart Radiator Thermostat £69.99

Wow, that gets expensive quickly when I am looking at perhaps a dozen radiators


 
Posted : 28/10/2021 11:23 am
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Does it make any sense to get Hive or other such smart heating systems
It makes sense (to me) in [i]any[/i] scenario. Why would you want to use 1940s tech in 2021?! I know others disagree, YMMV 😃

The main benefit is zoned heating but you need to fit smart TRVs to all rads really (we've left a normal one in the bathroom though). Like you we have a couple in a large hallway which is a bit of a waste to heat!

At a minimum it makes it very easy to schedule heat on a per-room basis (I've always found non smart controllers an unintuitive nightmare that involves digging the manual out 🤣) but depending on what systems you go for and how deep you want to dive you can set up other stuff like voice control which the Mrs will probably appreciate, automatically heating when you're out but heading home, dynamic scheduling based on occupancy or Google calendar, etc.

Wow, that gets expensive quickly when I am looking at perhaps a dozen radiators
Black Friday is coming up soon, I bought my DW setup last year when Amazon were doing very decent discounts - £85 vs around £200 I think for starter kit of controller, wireless room thermostat & 2 smart TRVs.

The Drayton stuff is a lot cheaper than Tado even at full retail - under £40 per smart TRV. There are pros & cons to both systems, a fair few threads on here discussing them in detail!


 
Posted : 28/10/2021 11:26 am
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Just looking at the Tado system. A new thermostat and wireless controller is £199 which is one per house. Then each radiator vale – Add-on Smart Radiator Thermostat £69.99

Wow, that gets expensive quickly when I am looking at perhaps a dozen radiators

well yes, exactly.

Manual TRVs everywhere, turn them down in the rooms you don't use... might be the easy route to non-wallet gouging happiness?


 
Posted : 28/10/2021 11:31 am
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[i]Manual TRVs everywhere, turn them down in the rooms you don’t use… might be the easy route to non-wallet gouging happiness?[/i]

That is where we are now. Just wanted to be sure I wasn't missing a trick.

This whole heating the house before you return home sounds good but as my bins go out more than me it seems a somewhat redundant benefit.


 
Posted : 28/10/2021 11:34 am
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Manual TRVs everywhere, turn them down in the rooms you don’t use
does anyone [I]actually[/I] bother to do this regularly though? (Cue posts from hundreds of outraged STWers claiming that of course they do 😃)
Plus you need a supercomputer for a brain to calculate what going from one arbitrary number to another is accurately going to do to the temperature! 🤣


 
Posted : 28/10/2021 11:47 am
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This whole heating the house before you return home sounds good but as my bins go out more than me it seems a somewhat redundant benefit.

My bins didn't come home last night. Dirty stop-outs.


 
Posted : 28/10/2021 11:49 am
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Wow, that gets expensive quickly when I am looking at perhaps a dozen radiators

I've looked at this, as my girls are now all away at uni, and the thought of spending in the region of £800 on this didn't work for me. Also, when I looked at it, the smart TVRs were not compatible with the valves on my [older] rads - so it would have required new valves also.
Given that I can just go into the rooms and turn the existing TRVs down the smart bit just doesn't justify the cost.


 
Posted : 28/10/2021 11:59 am
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Yes it is worth it if you get smart TRVs

Are all TRV threads equal? So I couldn’t just swap the manual TRVs with Smart ones without changing the actual valve?


 
Posted : 28/10/2021 12:04 pm
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does anyone actually bother to do this regularly though?

I just have done of the back of this thread, they were all on max, as they have been for pretty much the entire time we’ve lived here.

I might try and be better from now on.


 
Posted : 28/10/2021 12:06 pm
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Are all TRV threads equal? So I couldn’t just swap the manual TRVs with Smart ones without changing the actual valve?
my smart TRVs came with I think 3 different adapters, one of which fitted so just a straight swap. No idea how many different standards there are in total though.

I might try and be better from now on.
that's a no then 🤣


 
Posted : 28/10/2021 12:11 pm
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The Tado ones fit onto the existing valves assuming they are not SharkBaits old ones.

People who do adjust the existing manual TRVs - you do know about balancing the system, right? If you adjust one valve then you should also adjust the others to keep the system balanced. If you have then all set to low and then turn just one up to high, all of the low ones will get colder...


 
Posted : 28/10/2021 12:23 pm
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I just use jumpers and warm socks!

Heating is still set for morning and evening busts to coincide with wife getting up/going to work and coming home. I work from home and just layer up. If the house gets too cold the heating does kick in at about 15degrees in the day.

However the big difference is I'm in a small study and closing the door means the large monitor (currently at 33degrees) acts as a radiator and effectively heats the study well.


 
Posted : 28/10/2021 12:44 pm
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Balancing a system is where it gets complicated with after market smart controllers.

The boiler return temp needs to be controlled, so if you cant control its output and then return heat (rads do this last bit, less rads = less cooling), then your boiler becomes inefficient.

My system was a pain in the butt to set up as it's heatmiser on the UFH, then rads upstairs on the Vaillant system - it's got 4 wiring/control boxes before the boiler controlling all sorts weirdness. In hindsight, i wish i spent a lot more and just plumbed (boom) for 1 system to do the lot. It does work mind, though the missus seems to be able to tell a massive diffference between 20c in the summer and 20c inthe winter... <shrug>


 
Posted : 28/10/2021 12:44 pm
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you do know about balancing the system, right?

you know about the other valve on the radiator, the non-adjustable one?


 
Posted : 28/10/2021 1:01 pm
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Worth saying that Tado stuff is very often on offer. We paid £35 per TRV which is much more reasonable!


 
Posted : 28/10/2021 1:03 pm
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The boiler return temp needs to be controlled, so if you cant control its output and then return heat (rads do this last bit, less rads = less cooling), then your boiler becomes inefficient.
all greek to me as I know **** all about plumbing really, my smart controller came with optional wiring terminals for OpenTherm which my ancient boiler does not support, but I guess if it did that would cover this?


 
Posted : 28/10/2021 1:05 pm
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Just turn the rads down in the "cold" rooms, Shirley?


 
Posted : 28/10/2021 1:21 pm
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One thing I picked up (on here I think) was to put the smart TRVs in the rooms you don't use as you can keep them off and the smart thermostat does the rest of the house. Sounds like the answer for the OP. Or just a better thermostat for the whole house as they use most of it daily anyway. If you do go down the route of smart valves then keeping doors shut will help them control those "zones".

One suggestion up there /\/\ to move the thermostat around doesn't make sense to me. Even with smart valves, how does the system know where the 'stat is? Individual smart valves with educated users to control them should be fine. Just remember to turn them back down when you leave the room.

Could always get into the realms of smart home control where you have motion detectors in each room turning valves on and off. Gets expensive but should work really well if you take the time to set it up and easily within the ability of most users if they can drive a smartphone.


 
Posted : 28/10/2021 1:30 pm
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People who do adjust the existing manual TRVs – you do know about balancing the system, right? If you adjust one valve then you should also adjust the others to keep the system balanced. If you have then all set to low and then turn just one up to high, all of the low ones will get colder

You do know that balancing is done on the lockshield and not the TRV don't you?
A smart TRV is just a manual TRV with added complicating bits - it's no different to turning the TRV down by hand.

Could always get into the realms of smart home control where you have motion detectors in each room turning valves on and off.

Sounds bonkers. So you go into room 1 and the boiler fired up to heat that room, but 15 minutes later (before room 1 heats up) you've left room 1 and gone to room 2 - so the boiler starts heating room 2 instead, but then you move again.....
I can't help but feel that there's a lot of overthinking going on!


 
Posted : 28/10/2021 3:07 pm
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Sounds bonkers. So you go into room 1 and the boiler fired up to heat that room
I'm at that level of home automation now, but yeah it doesn't work for heating for that reason. Adaptive and/or dynamic scheduling [I]does[I] work though, and is pretty clever. Funnily enough motion detectors aren't the best devices for room-presence full stop... already copped a bollocking from the Mrs due to the lights going off because she wasn't splashing around in the bath enough 🤣


 
Posted : 28/10/2021 3:18 pm
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No need for smart trv’s. just get manual ones. The smart thermostats can move with you and why wouldn’t you adjust manual trv’s as long as you understood how your system works and when the heat demand was on.


 
Posted : 28/10/2021 6:11 pm
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Moving the thermostat around is a bad idea. The system doesn't know where it is so if you put it in a corner of the house that is hard to maintain heat the whole house will be roasting with the system on full the whole time.

As for my suggestion of fully automated room by room etc. It could work depending on you length of time in each space. You'd need to regularly spend 1hr+ in each area at a time to make it work I reckon.


 
Posted : 31/10/2021 9:33 am
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I know this isn’t useful to the OP, but can we please acknowledge that heating to 25 degrees sounds like a living hell!!


 
Posted : 31/10/2021 11:10 am
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Hive say not to put their thermostat in the same room as a TRV. Though I wonder if that's because they sell smart TRVs.

you know about the other valve on the radiator, the non-adjustable one?

Yeah, don't adjust them when they're old rads. They leak when you do! 😄


 
Posted : 31/10/2021 1:55 pm
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I was advised by one of the heating engineers who came out to service the boiler that using the built in timer in a 15 minutes on-15 minutes off rotation throughout the winter months is quite cost effective and keeps the house warm to a good level.


 
Posted : 31/10/2021 2:09 pm
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I've been disappointed in the smart thermostat installs I've had.

The Nest (Gen 3 and E) is a pleasant device aesthetically and in its tactility but its smarts are predicated on whether you have left the home or not and that's about it. Left on auto-learning it instigated a schedule that set the wrong temperature almost at every stage. It doesn't have a useful boost function and you have to set an aggressive schedule to turn down the temperature in case someone sets it ridiculously high. Best feature is you can PIN lock it and restrict temperature adjustments. Eco setting is pointless - it isn't something you can switch to on the device with the PIN set; it should just be the extreme end of the temperature adjustment on the device.

Hive is godawful. It does have boost but doesn't do anything smart. It is basically a programmable where you set the schedule on an app on your phone. Why oh why don't these apps have template schedules? Plus the thermostat frequently goes out of calibration and you have to stuff it in the freezer to get it working again.

Can't comment on any others.


 
Posted : 31/10/2021 2:18 pm
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Hive say not to put their thermostat in the same room as a TRV. Though I wonder if that’s because they sell smart TRVs.

Nah. It is basic function. The thermostat will call for heat if it is low. It will switch off the boiler when it is satisfied. If you have a TRV that switches off before the thermostat is satisfied, that room temperature will never increase enough to satisfy the thermostat. The "call for heat" then becomes "permanent on" and the boiler will cycle on and off repeatedly based on its target circuit temperature. This will be inefficient and with all the house TRVs closed (satisfied) you'll need a good bypass valve to ensure the pump isn't just stalled pumping against a set of closed valves.

If you have a interlinked system where the call for heat is based on whether any individual smart TRV is calling for heat, my comment above won't apply.


 
Posted : 31/10/2021 2:25 pm
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I was advised by one of the heating engineers who came out to service the boiler that using the built in timer in a 15 minutes on-15 minutes off rotation throughout the winter months is quite cost effective and keeps the house warm to a good level.

Another theory is with thermostats, just keep the timer always on. Theory being that energy/cost to heat a house from cold is greater than top ups to keep it at temperature.

Not sure, it may depend on the system and how efficiently the boiler and thermostats work, and insulation. I've tried it and not seen a noticeable cost increase but then I've switched to off overnight and not seen much difference either. i.e. cost of the odd top up overnight is much the same as the longer heat up in the morning.

Hive is godawful. It does have boost but doesn’t do anything smart

It does have "read-by" feature which works out how long it actually takes your system to heat to a particular temperature and will come on earlier than scheduled to be ready by that time, depending how cool the house is.

In technology terms the 'smart' like a lot of smart devices is that it can be integrated with other smart devices and systems. A smart bulb isn't actually smart for example, but it can be integrated with a smart system. Hive will work with Alexa, Google, Siri, IFTTT etc, so can have complex schedules or triggers that way, or be triggered by other Hive products. Likewise most smart bulb manufacturer's apps are fairly basic, but paired with a major smart system it's a lot more "smart".

Aside from being a bit of a closed system, uses it's own hub and not that cheap, I can't say Hive is awful. It does the job far better than the "dumb" wireless thermostats British Gas supply, and battery lasts massively longer. Noting Hive is owned by BG/Centrica.


 
Posted : 31/10/2021 3:46 pm
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does the job far better than the “dumb” wireless thermostats British Gas supply, and battery lasts

I specced hive because it was battery powered and I needed that for the application.

My experience with the Hive though is that it fails to know what temperature it is and needs resetting by putting in a freezer. That's a pretty fundamental failure to be any good as a thermostat.

The Alexa integration isn't worth anything. The general nature of these consumer smart platforms is they need imperative instruction. "Do this NOW", "Do that at some time". There's nothing smart about it. They're basically just gadgets that need programming so they appeal to programmers. What's missing is any sort of visionary product management delivering behaviour. In Alexa's case that's partly down to the vendor having low ambitions for maintaining the "Alexa skill" and the infrastructure hosting their API (on AWS no doubt) but the platform itself is stateless and imperative so behaviour is entirely delegated to third parties and is very patchy.

This thread is the embodiment of that. The thermostats and their extended smart ecosystem can geofence the user, so the function is "switch off when not at home". That's demonstrably useless for the scenario when you WFH.

Just like all consumer tech, the best bits of the tech are gimmicky and pitched at closing the sale to customers who can be nudged by marketing and media into buying tat (guilty as charged). You're not getting a trimmed down version of a commercial building management system. You're getting a one trick wonder where sooner or later the security certificates that let them phone home will expire and you'll have forced obsolescence and you'll be buying more tat, hastening the end of human existence on this planet with all the excess CO2 from sourcing, manufacturing, packaging, shipping, running the server farms, disposal.

/Rant

I'm heading back to my bothy


 
Posted : 01/11/2021 8:21 am
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I’m heading back to my bothy
good idea! Sounds like you could do with stepping away from technology for a while 😀


 
Posted : 01/11/2021 9:17 am
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you know about the other valve on the radiator, the non-adjustable one?

Please educate me, @mrmonkfinger

Re: Thermaskirt - have only heard about these in passing but I'd be wary that they were A) not likely to put out enough heat and B) incompatible with the heat-pump boilers that may be required in the next 10 years.


 
Posted : 01/11/2021 10:30 am
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The other valve is usually a "lockshield" valve. Their purpose is to provide resistance to flow through each radiator so that the flow has the motivation to flow evenly through all your radiators rather than sending all the water through the path of least resistance in a single radiator. Slowing the flow also assures the return temperature is low enough for a condensing boiler.

This is called "balancing" your radiators. Usually involves thermometers on the feed and exit pipes being moved around from rad to rad as you make adjustments.

The lockshield is so that it is set once and doesn't get tampered with.


 
Posted : 01/11/2021 10:37 am
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I stand corrected on the radiator balancing issue. I knew that you balanced with the lock shield valve but thought that if you then turned the TRV valves on half the radiators to low, throttled their flow, it would affect the flow to the others.

I am not clear how it doesn't as I assumed that if you balanced say 10 radiators perfectly for when the TRV was fully open then there would be a difference if you mostly closed half of them but then I am not a heating engineer.


 
Posted : 01/11/2021 11:04 am
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but then I am not a heating engineer.
me neither but surely the whole point of a TRV (regular or smart) is that it's self regulating?


 
Posted : 01/11/2021 11:47 am
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We recently got a Nest thermostat when we had a new boiler installed. I wasn't convinced, but my Wife seemed keen to have some 'smart' functionality, although I am fairly convinced that she had no idea what that actually meant for a heating thermostat/controller.

Anyway. It's pretty meh.
The smart scheduling is pretty useless. Maybe it can't cope with me working from home some days and other days in the office? Dunno. We've left it to do it's thing now for a month, thinking that it probably just needs enough time to learn our habits. But, nope. It just doesn't seem to have done as good a job as I would have done by entering it all manually.

Prior to our Nest, we had a Honeywell wireless thermostat & controller. The thermostat sat in the living room & the controller had so many options that there were very few times when the heating was on when we weren't about.
The most annoying thing about the Nest is that it will go into eco mode & turn the heating off if you leave the house, but then won't turn it back on until you get back home. So, if you go out for the day on a cold day, you get back home & the house is freezing cold & it only turns the heating on once you get back in the house. You can manually over-ride the 'away' setting which will force it to come on, but that doesn't seem very 'smart'. It's just remote functionality.

People should be wary of turning the TRVs down in unused rooms, if this is for prolonged periods. Probably a bit of a generalisation, but in a lot of houses if the room gets too cold you can end up with condensation & damp in that one room.
My parents do this & wonder why certain rooms are like damp ice blocks. I try to explain to them, but it doesn't seem to sink in.


 
Posted : 01/11/2021 11:53 am
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Each TRV is self regulating, yes, but I think you need to look at the whole system as well which is where the balancing bit comes in.

My only experience of balancing radiators was helping my uncle when he was doing it to his new self-built house when I was a kid (pre-TRV) and basically you had to make sure each radiator was the same temperature. No TRVs meant everything was fully open.

I would have though that TRVs opening and closing their valves would affect this whichg is what I was originally trying to say.


 
Posted : 01/11/2021 11:55 am
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We have Honeywell EvoHome through out the house.

It was very expensive but is a nice comfort thing.

I am in the house by myself today so just got a bedroom radiator on at the minute, however I am about to go down for lunch so have turned the lounge rad on from my phone.

If its just more than myself in the house we may put the whole of the downstairs on too. At weekends the rad's are on downstairs but not upstairs.

Does it save money? I dont have a clue as I installed when I moved in to the house. But it certainly feels efficient.

A Hive/Nest on its own will make no difference, apart from learning when to turn the radiators on to get the temp right in that one room. A smart TRV system will turn the rad's on in each room independently to get them to the required temp for that room.

The cheapest solution at the minute would be to turn off your manual TRV's in the rooms you are not using (so long as you know what level to turn them back on to). IMO either stick manual or pay £££ and go full system, no point with just getting the likes of Hive etc


 
Posted : 01/11/2021 12:10 pm
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I would have though that TRVs opening and closing their valves would affect this whichg is what I was originally trying to say.
yes, but then the [I]other[/I] TRVs would adjust to compensate. Are you bored & trolling again 😃 (either way, on a smart heating system that doesn't rely on 1940s tech, it's a moot point!)


 
Posted : 01/11/2021 12:14 pm
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We recently got a Nest thermostat when we had a new boiler installed. I wasn’t convinced, but my Wife seemed keen to have some ‘smart’ functionality, although I am fairly convinced that she had no idea what that actually meant for a heating thermostat/controller.

Anyway. It’s pretty meh.

I bought a Nest for my work unit many years ago when it was pretty much the only "smart" (as in connected) option, primarily because the existing thermostat/control unit was absolutely horrendous to program/schedule whereas the Nest is a doddle and can easily be adjusted remotely if e.g. no-one will be in because it's a bank holiday. Never used any of the auto-adjusting features/away mode etc. It doesn't have zoned heating but then we don't need it. Has worked flawlessly for years but would not recommend it unless your needs are [I]very[/I] basic i.e. just want to be able to schedule easily from an app and check/adjust temp remotely. Assume Hive is broadly similar.

The cheapest solution at the minute would be to turn off your manual TRV’s in the rooms you are not using
interestingly (or not 😃) it was only when I fitted my smart TRVs that I discovered most of the regular ones were stuck and didn't actually do anything 🤣


 
Posted : 01/11/2021 12:22 pm
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Our Hive is only used as a timed/programed zone control. The thermostat side of each Hive TRV is a bit flakey/needs calibrating a lot, so i just use it to completely turn on/off certain radiators.

Mostly upstairs (with one downstairs in the hall), just to open in the morning when the heating is on to warm up before work, off during the day when we are downstairs then back on at night before bed. The only exception is the office, where a: the desk is right next to the rad and b: when i open the TRV the rad heats up so quick it doesn't need advance warning! The Hive TRV comes on in the spare room for an hour during the night just to keep any damp at bay.

Could do with a couple for downstairs as well, just to lock out the rads in the living/dinning room when the log burner is on (cant reach normal TRV as behind furniture). The main Hive stat is in the kitchen, with a normal TRV fully open on that rad. as mentioned above, if you have a TRV and thermostatic controller in the same room they can end up fighting each other in certain circumstances. You should also have at least one rad in the system with no TRV on at all (often the bathroom) this should be enough to reduce the return heat temp to the boiler if all other rads were closed. our boiler just wont fire if the return temp is too high, the pump keeps circulating the water until the temp drops enough.

None of the above is 'smart' though, all set up through the app. It doesn't learn our habits, Geofencing is only an alert not an action within the app. It really cant cope with a flexible shift pattern for example. I work mon - fri same hours each week, Mrs F can work any 3 out of 7. There isn't an effective way of managing this through Hive that i have found.


 
Posted : 01/11/2021 12:42 pm
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Just on the balancing thing...

When all the TRVs are shut, the flow will go to the last remaining path of least resistance. This is easy to design in with either a bypass or a permanently on radiator.

When all the TRVs are open, you expect to get an proportionate flow through all the rads. This is hard to achieve and is why you need balancing.

The pressure drop across a pumped system with an incompressible fluid (water) is determined by the flow rate and resistance to flow. It is just like calculating resistance in an electrical parallel circuit.

1/R = 1/R1 + 1/R2 + 1/R3 ...

or 1 = R/R1 + R/R2 + R/R3 ....

You can think of this latter form as the proportion of the total flow going through each radiator. If R1 has a resistance close to zero (path of least resistance), then the total resistance R will be close to zero and R/R1 will be close to 1. Almost all the flow will go through that one radiator.

Lot's of approximations in this. The theory gets as far as saying it is easier to balance circuits where all radiators have some form of restriction rather than trying to balance things with everything wide open.

That restriction also reduces overall flow rate lowering the return flow temperature. This is good for boiler efficiency (condensing).


 
Posted : 01/11/2021 1:03 pm
Posts: 1724
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Genius home / Genius hub will do what you want.
It has a footprint mode which tracks the rooms you populate, when and builds a heating profile around it.
Seems pretty smart from the reviews I've read but I imagine the payback is hefty.

I plan on getting it for the house but want proper integration through the API so I can do other things with the room sensors.


 
Posted : 01/11/2021 10:49 pm
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Honeywell Evohome allows each room to be its own controlled zone - the main unit has a thermostat that can be used but doesn't have to be. It worked brilliantly for me when I was on oil as it kept the cost down.

For the OP it's overkill - if you're moving around the house in the days there's no massive benefit to be had, except that your wife and yourself can set the rooms to your own preference.

Re her approach of turning the thermostat and opening the window - my ex used to take that approach. Get Greta around to have a word !
The evohome system has an "open window" detection facility where if it detects that it's trying to heat the room but the temp isnt changing it determines that a window has been left open and turns off the heating in that room.
You can also program in an offset to the temperatures - intended for calibration but could be used for whatever purpose you decide.


 
Posted : 02/11/2021 7:37 am
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When all the TRVs are shut, the flow will go to the last remaining path of least resistance. This is easy to design in with either a bypass or a permanently on radiator.

If it's all fully smart TRV's the boiler and pump won't fire up as they rely on a TRV calling for heat via the hub/controller. From what I can see of our newly installed boiler a bypass is now a feature on heating circuits. The plumber installed one as it wasn't present.


 
Posted : 02/11/2021 8:05 am
 a11y
Posts: 3618
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The evohome system has an “open window” detection facility where if it detects that it’s trying to heat the room but the temp isnt changing it determines that a window has been left open and turns off the heating in that room.

I've had the evohome system here for a couple of years and I've been tempted so so many times to switch that on, but thankfully the kids have learned to shut windows/doors without me doing so!

Similar to @FunkyDunc, we installed Honeywell evohome not long after moving in so I don't know if it's saved us money compared to a non-smart system. However, compared to our previous house we’re using a lot less gas which surprised me, as ours should be a much less efficient and much more expensive house to heat.

Previous: 262sqm 6-bed detached, 2006-built, modern insulation etc.

29,271kWh gas over 12 months

Current: 178sqm 4-bed detached, 1870s-built, minimal insulation, high ceilings etc.

21,568kWh over 12 months, including significant WFH during lockdown

That’s with 9 individual zones, including a conservatory. Hate to think what our gas usage might be without a smart system.


 
Posted : 02/11/2021 8:41 am
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Genius home / Genius hub will do what you want.
It has a footprint mode which tracks the rooms you populate, when and builds a heating profile around it.
sounds good but damn - the price 💰💰💰😃
Would be interesting to see a proper technical analysis/review of it but couldn’t find one. Room occupation dynamic scheduling is cool - I’ve manually scheduled our heating based on what I [i]think[/i] our routine is but it would be interesting to see actual data (although IME PIR motion detectors - which it looks like these are - aren’t an ideal solution for that).
API is open though - looks like the Home Assistant integration can access the data, including room occupation. Be very interesting to know how reliable that part is, if you end up investing!


 
Posted : 02/11/2021 8:44 am
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Controls now commissioned by the sparks today. I'm waiting for the TRV's to calibrate before throwing the heat on demand switch and allowing them to control the boiler. Should be live early next week once all the firmware updates are in place too.


 
Posted : 04/11/2021 4:59 pm
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I stand corrected on the radiator balancing issue. I knew that you balanced with the lock shield valve but thought that if you then turned the TRV valves on half the radiators to low, throttled their flow, it would affect the flow to the others.

They should all be in parallel and the balancing is to account for the different pipe lengths to each rad. Once balanced the flow should evenly divide between all radiators and turning one of more off will make no difference.

If you turn too many off the pump might over pump, but IIRC most modern CH pumps can sense flow and back off as radiator TRVs switch off (ours certainly does).


 
Posted : 04/11/2021 5:37 pm
Posts: 12865
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No experience of it so can't recommend personally, obviously there's a few on here very pleased with it tho: Tado starter kit & 3-valve packs almost half price on Amazon at the moment.

https://www.amazon.co.uk/dp/B098BKHT3R?smid=A3P5ROKL5A1OLE&tag=pepperugc03-21&ascsubtag=2257400699
https://www.amazon.co.uk/tado°-Radiator-Thermostat-Universal-Mounting/dp/B098B2XP8C/ref=pd_bxgy_img_1/260-6611601-1495959?pd_rd_w=4KAh6&pf_rd_p=c7ea61ca-7168-47e3-9c8b-d84748f5b23c&pf_rd_r=YG2TNEDCYDAV0H9NKEVG&pd_rd_r=6fab7bb2-edba-4805-bde8-7fc1034c51bc&pd_rd_wg=YAUhS&pd_rd_i=B098B2XP8C&psc=1


 
Posted : 09/11/2021 10:28 am
Posts: 918
Free Member
 

PSA
Tado starter kit currently half price in Screwfix
https://www.screwfix.com/p/tado-v3-heating-hot-water-wireless-smart-thermostat-starter-kit/141kt


 
Posted : 21/02/2022 10:22 am

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