New house, built to last iteration of Scottish building regs. So well insulated, well airtight (you can feel it when you go to close the doors...) and four background extractor fans. It really, really holds heat well - last night was around freezing and the heating barely came on this morning/was still 16*c downstairs and 17.5*c upstairs.
Ideal Logic H24 with two heating zones and a mains pressure water tank (is heated by both boiler on timer and by electric 'trickle' from the 5 solar panels). Zone 1 downstairs plus one small hallway rad upstairs. Zone 2 upstairs with one small rad downstairs.
Day 1 the developer had cranked everything up to maximum. I have the TRV's dialled back to 3/middle setting everywhere. I have dialled the boiler back to 50*c. Two zone stats set at 18*c.
But we cannot seem to get the balance right. There are three non-TRV radiators, all three of which belt out heat so the hallway, landing and dining area are really hot, but rest of the house is a tad cooler, particularly bathrooms and one bedroom, as the heating will not kick on to just pop some warmth round the house, particularly Zone 2/upstairs.
Goal is even heat, not higher temps. Also to keep bills low....
Can I slow down the flow on the non-TRV radiators to balance things into other radiators?
Should I put the boiler up more to get 'bursts' of heat?
Any other suggestions?
You need to open all the TRVs fully and then balance the rads with the lockshield valves on the other side. Rads closest to the pump will heat up most because water will follow the easiest path. Generally you will need to close down the lockshields on the rads nearest the pump most in order to increase the resistance through those rads and therefore push the water to the more distant parts of the system. It's a good idea to let the system go cold, then switch it on full and run around the house making a note of the order that the rads heat up - you then have an idea of which rads need the most restriction.
As above - balance the rads.
But also, in a well insulated house you're best off running the radiator flow temperatures as low as possible, with long heating periods. That will maintain more even temperatures.
Agree with balancing the rads with the lock shield valves, ideally you would take the temperature of the incoming pipe and then set the lockshield to achieve the required temperature drop across the rad, I think.
Also where are your stats? If in the hallway/warmest areas, they are going to shut down the heating before the larger living areas warm up. But if you get the balancing right and the hallway is slightly cooler than the rest of the house this won't matter.
As b33 says, get the flow temperature as low as possible. Keeping the boiler running at a lower temperature is more efficient than it turning on and off every 15 minutes. Ideally, it should have been designed so that each radiator is the perfect size for each room, so the TRVs should not be required. In reality, the Installers CGAF about the heat loss for individual rooms, and will cut corners, as thats the way they have always done it. The maximum flow temperature should be 55 degrees now, so your current 50 degrees is not much below the maximum.
It’s part of the Building Regs, and the Developer should have the heat loss calculations, they should certainly have submitted them for the Building Completion Certificate. But I doubt they will let you have them, as your boiler is far too big for your house, and if they didnt know that, they really shouldnt be fitting out houses. I know that without even seeing it, as any modern house below 5 bedrooms should need less than 10kW to heat it.
Why in a modern house wouldn’t you have room thermostats that control the temp of each room ?
Why in a modern house wouldn’t you have room thermostats that control the temp of each room ?
As it is less efficient. More control, but less efficiency. Boilers use more energy when starting up/shutting down than when they are running gently at a low level. More than one controller (stat/TRV) will mean the boiler will be on for one zone, that zone is satisfied so goes off, then another zone wants heat, so the boiler starts up again, and the cycle continues. Of course there will be some overlap, but overall it is a poor way of controlling the heat source.
Basically, it is far more efficient to run constantly at a lower temperature than to come on at full power for ten minutes, turn off, repeat again etc. which is what a poorly set up boiler does. In that form of heat, the graph of temperature insde the house goes up and down a lot in a 2 degree (or more) range. A well set up ‘open’ system will have a far smoother temperature graph showing the lack of start and stop cycles. With efficiency comes fuel savings, so its cheaper to run it, as well as less starting cycles which wear out parts etc.
Building Regs have required a room by room heat loss assessment whenever a new heat source is fitted for a number of years now. It is mostly ignored, hence we have a 24kW boiler fitted to a modern house that would be fine with 10kW. Having a room by room heat loss survey would allow all rooms to have the correct sized radiators/emitters fitted, this allows each room to get to the same temperature, so shouldnt need any other form of control apart from one thermostat.
Heat pumps take this a step further, and have something called Weather Compensation, where once set properly, there is no need for an internal thermostat, as the unit has learned what is required, and adjusts the temperature it puts out in relation to the outside temperature.
Heat pumps take this a step further, and have something called Weather Compensation
I fitted external temperature sensor to my old boiler. It worked with room stat in combination.
It was fitted a year after the boiler was, so I was broadly able to compare gas usage. Despite a colder year, my gas usage was down 8%. I just do not understand why they are not standard.
I've got downstairs more balanced, but upstairs is barely drawing heat as downstairs heat is rising. While that's a Good Thing in showing the house is well insulated, it's leaving a a bathroom and a bedroom cold at present.
There’s a weather compensation module for the ops boiler https://idealheating.com/products/weather-compensation-kit
don’t know if they’re all created equal - it’s a bit hazy about what it does. The one on my boiler will modulate down to almost nothing (ufh runs between 21 and 30c)
I was amazed (unsurprised) at the system fitted to my sisters Welsh new build 2 years ago. The building regs made reference to weather compensation and smart controls but there were a load of ors and exceptions (system must have at least 2 of the following features). So what was actually installed was a single zone with rad stats and a combined stat time clock. Not really any more advanced than was fitted to my parents house 40 years before.
that said, however good the system, there’s no accounting for users. I can’t get my sister to even let the time clock do the work (it is the least intuitive thing I’ve ever seen). I’m pretty sure she’s still switching the boiler on and off in the cupboard when she wants heat. People are so used to poorly insulated homes in the uk they have trouble adapting to anything that doesn’t dump all its heat in half an hour b
There are three non-TRV radiators, all three of which belt out heat so the hallway, landing and dining area are really hot
All the radiators should have TRVs unless there's roomstat in the same room. Sounds like the developer has not fitted one to the dining room.
All the radiators should have TRVs unless there's roomstat in the same room. Sounds like the developer has not fitted one to the dining room.
May be necessary if there's no bypass valve on the system.
I found a cheap two-probe pipe thermometer on AliExpress for £10 which I used to set the temperature drop across the radiators.
The ESI ES3247B programmable timer is shite.
Suggest me a cleverer thing that has more than two heating periods. Needs to have two zones and hot water. Not too bothered about app. Certainly not paying for a subscription or being behest to a tech company for updates or being connected to web.
Ideally I can DIY in.
I'd add smart thermostatic valves in each room (apart from the smallest radiator in the house if you don't have a bypass). It sounds like you have the existing smart valves on your highest demand zones as you are overheating other rooms when they are on. Smart valves will effectively balance your other radiators for you without you having to re balance when seasons change. They shouldn't be making more demands for the boiler to start as it sounds like your existing smart zones cool down quicker. Just don't set those "new" zones to a higher temperature and you should be all good.
Suggest me a cleverer thing that has more than two heating periods.
The Honeywell / Resideo Evohome system is good, though pricey.
as your boiler is far too big for your house
Surely it was sized to be able to run the shower etc? As long as it's able to run at a lower output (5kW for that boiler?) for the heating its max output is sort of irrelevant
+1 for Honeywell, but there are quite a few systems now that do more than two zones. Tado, Drayton, Kasa to name a few. I'd probably go for Tado if I was buying now (I've got a 9 zone Honeywell system that I bought about 10 years ago ... It saved me about 20% in gas bills at the time by keeping less used rooms cool when not in use).
Surely it was sized to be able to run the shower etc? As long as it's able to run at a lower output (5kW for that boiler?) for the heating its max output is sort of irrelevant
It has a water tank/cylinder so water heating output is irrelevant. From googling, it is possible for that boiler to modulate down to around 6kW if set up correctly. I’d estimate Matts house to have a heat requirement of 8kW or less. 6kW is still too much for days when the temperature is above 5 degrees, leading to inefficiences in cycling. The losses may be low, at a guess, £50/year, but, it wouldnt have cost any more to design it correctly, and make it a really well running efficient heating system. This is the problem we have in this Country, in that people are accepting the low standards, when it is quite possible to get a better outcome for no, or very little extra cost.
My gas boiler fitting friend is still stuck in the 80’s, and always says he never gets called back to houses that are too hot, only the ones that are too cold, so he over-specs everything, and in doing so, the HouseOwner pays the extra bills for his lack of calculating the heat requiremnt, but, they are warm, so dont question the higher than required bills.
If the house is well insulated I would (this might take a bit of experimentation to get working right, but will be simple, low maintenance and low cost.)
- open all the TRVs and balance the flow across the radiators using the lock shields
- Lower the heating flow temperature as much as you can (will be limited by the size/output of your radiators. It will be a bit of trial and error - if you go too far and the house isn't reaching temperature
- install the weather compensation module on your boiler
For the controls will depend partly on how they're wired (I had a flat where there the room stats were wired, but powered by AAA batteries not the cable. Changing the controls without altering a mass of wiring wasn't possible) .
Then install two timer/thermostats - they'll have multiple time periods which you can specify different temperatures for so you can have the house heated to a lower temp rather than being off completely between heating periods. eg 20C when in use, setback to 15 or 16 overnight and when house is always empty.
Potentially can then do away with all the TRVs.
The oddity is your hall radiator running of the "wrong" circuit - surely that isn't helping your controllability now.