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We moved house last year and it's always on the cold side. Have just installed Hive as we currently have an old CH + HW boiler and had an old wired thermostat I didn't trust.
Hive data is showing that at its lowest temp the house can be as cold as 14.5 degC (6am and 3pm yesterday).
It was reasonably fresh yesterday (we're only on the outskirts of Stockport) and so I turned it on at 3pm so the kids didn't freeze when they got in from nursery/school. Even after having the heating on for 5hrs, it topped out at 17.1 degC (a mere rise of 2.5 degC)
So I'm wondering whether I'd be better off be running the heating for 15hrs (6am to 9pm) or even 24hrs rather than have it at full chat for 2 extended periods in the day whilst I work out how to insulate things a bit better (odd 100yr old house with limited access to and in in the loft space and eves).
Basic tests that monitor the gas reading aside is there anything else I could do to check efficiency?
I used to think it would be more efficient to keep the house at temp 24 hours a day, instead of letting it get cold and then heat up again.
When I changed to a smart thermostat I discovered that its more efficient to only have the heating on when you need it. (By quite a lot)
a new boiler and radiator system in my house have made me realise how ineffective the one actually was.
Insulation. Insulation. Insulation.
I live in a 1820's stone built house. Previous owners did a full refurb.
Insulated everything as much as possible.
Easy to get the rooms warm and they stay warm for ages.
I agree about the insulation. The difference it made on my draughty attic flat is immense. Horrible job to do crawling around the eaves etc stuffing insulation everywhere and everywhere
Is the heating loop temperature set high enough on the boiler?
Is the heating loop temperature set high enough on the boiler?
Yep, set to max.
Most of the rads are flat double panel with no convectors on the backs and these will all be replaced as we decorate the rooms. We'll need a new boiler at some point along this journey as well.
We've got suspended wooden floors and enough space for me to crawl under and fit insulation between the joists...I've done this in the kitchen already and will do one of the lounges next. Doing this is going to be far easier than the loft space.
The house is sort of two halves...the front half is like a lodge with only a single room upstairs at the front. There are eves either side of this room that are inaccessible (bricked up and no access). The rear of the house is more akin to a normal house. Neither parts of the house have a normal loft space,2-3ft max height. All the loft space is accessed via 2 glass windows in the ceiling which are ~4m above the stair case mid point. There is insulation up there but it looks pretty old and I know I should add more. Just going to be difficult getting it up there and then moving around (I'm 6'7"). Really looking forward to that job.
Re: insulation, don't make the mistake of blocking up eaves and stuffing every hole. Properties need to breathe or you'll get condensation.
Look to top up loft insulation, insulate around loft hatch and doors.
For solid wall you can look at external wall insulation or if you're prepared to lose a little room space, internal insulation.
Ensure that the property is adequately ventilated when done - trickle vents in double glazed units and decent extractor fans in kitchen and bathrooms.
I had mine on 24x7 for 2-3 months last winter, I need to get my loft insulation sorted though. Have also changed boiler and have smart heating controls since so might help (although now with the added complication of electric underfloor and wall heating in my bathroom that I still need to get the schedule sorted for).
This may be getting tedious but...
Even after having the heating on for 5hrs, it topped out at 17.1 degC (a mere rise of 2.5 degC)
...isn't right. How's the thermostat - is it in a wall somewhere warm (so it stops heating because it's nice and toasty)? If so, maybe see if you can get one with remote sensors, like Ecobee, Nest etc. Then insulation and windows first (if you can afford them). Then new boiler, possibly radiators.
Fwiw we have a 1920s brick house with no cavity walls and cast iron radiators and it was drafty. We fitted double glazing where there was single glazing, redid the loft insulation and got the boiler serviced, and added a remote sensor to the thermostat. We can definitely get it toasty in here - the challenge is getting it 'just right'!
Next will probably be replacing the older double glazed windows, but they're big so not looking forward to that...
No, I actually worked for BG in the 2000s for a bit, 'we' or rather they advised it was more efficient to heat your home 24/7 rather than just when you needed it. The truth was you needed a really efficient house (for the time) to make it work, most of the time you were burning gas to heat the street.
Something like Hive is a great idea, unless you've got sensitive pets home all day or whatever, only heat when you need to.
Our house is from around 1900, I might as well burn fivers to keep warm.
Hive has a 'temperature by' option, so it works out how long your house takes to get to that and switches it on accordingly. Works well here (modern 5 bed detached). This time of year it comes on around 5am to get it to 20 deg for 0700, and then it's on and off till about 10pm
How’s the thermostat – is it in a wall somewhere warm (so it stops heating because it’s nice and toasty)?
Thermostat is free standing and is currently in the hallway...which is probably the coldest area downstairs. It's not near the single panel radiator.
Windows are all double glazing (with the exception of the bathroom) and reasonably modern/not too old.
Looks like loft is top of my to do list but half the house downstairs I can't insulate as the roof parts are inaccessible (red triangles):
[url= http://i.imgur.com/V4J3VZG.pn g" target="_blank">
so what did the temperature in the rest of the house get to?
yes but only because the boiler seems to konk out if we dont. and when i say 'on' i mean enough to fire the boiler up a wee bit each day only.
insulaton is great to a point but i had to add mechanical air ventilation (nuaire drimaster system) to teh bathroom/bedroom landing/hall as it got mouldy due to condensation.
we also has issues with damp bridging across the foam ball type cavity wall insulation.
so what did the temperature in the rest of the house get to?
Not yet measured but only the lounge and possibly kitchen downstairs are slightly warmer...I'll look into a remote sensor.
Downstairs we have
Lounge - nicely warm but wife wouldn't want it any colder (but the boiler is in this room in an old fireplace)
Kitchen - nicely warm (insulated under floorboards though and half of the space has a heated room above, other half unheated above)
Dining room - bearable but not warm
Other reception room - cold (we have the TRV turned down in here)
Bathroom - just about warm
Upstairs:
Bedroom at front - warm
3 bedrooms at back just about bearable
Pretty graph of hallway temps:
[img] 
[/img]
It's a tough job in an old house. Our old end of terrace victorian had the same problem - the heating system simply couldn't put energy into the house as quickly as it was leaving and for a long while the house topped out at about 17C in some rooms in winter.
In answer to your question - no, you're not better leaving it on all the time. When a house is badly insulated the structure is always cooling it and you're better off blasting in as much heat as you can when you're home and letting it get cold when you're not.
What to do? Insulate and draughtproof. Ours was better when we'd:
- got more insulation in the loft
- refurbed/replaced the sash window frames and front door. seal up windows you don't need to open for ventilation so they're not draughty. the 'clingfilm' double glazing you can buy is a cheap temporary fix. made a big difference in a rental house one winter.
- thick curtains (in front of windows and doors.)
Might be worth looking at the size of the radiators and the boiler.
As an aside, in a very well insulated house the always on approach can make sense. New house has underfloor throughout that runs 18 hours a day at just a few degrees above room temperature. Internal temp is very stable and heating bills are super low.
Make sure the thermostat is in a room with a radiator that doesn't have a trv fitted. The trv will shut off and the hive will keetp trying to get to temp.
Make sure the thermostat is in a room with a radiator that doesn’t have a trv fitted. The trv will shut off and the hive will keetp trying to get to temp.
No TRV in the hallway so we're safe on that one.
you’re better off blasting in as much heat as you can when you’re home
The problem is it's taking 5hrs to get bearable 🙂
Don't forget about the roof on those bay windows. You will lose a lot of heat through those.
If you can, create a false ceiling inside and line with the thickest Celotex or Kingspan you can.
are the radiators in the rooms that are cold actually getting a decent amount of flow to them? i've just replaced 15yr old microbore with 15mm throughout and it makes a huge difference. I'm not sure any real flow was going through the old pipes.
I'd make the loft areas highlighted in red accessible with a couple of doors upstairs.
@jam bo - that could be a good shout. We're 10mm microbore throughout....possible job for when we replace the boiler I guess.
Don’t forget about the roof on those bay windows.
Hadn't thought of those. The windows are full height inside though so a false ceiling would prove difficult. We tend to keep the doors to these rooms closed and not use them in an evening.
Lots of things to mull over; thanks.
Mine is on all the time purely because I have pets so keep it at a comfy 21 degrees.
Before they were purchased I only had it come on in the mornings and evenings, about 2 hours before I came home from work or woke up.
interesting thread. I've been thinking of going down the Hive / Nest route. How easy are they to self install?
If the coldest my house got was 14.5 degrees then I'd never put my heating on at all.
Don’t forget about the roof on those bay windows.
Hadn’t thought of those. The windows are full height inside though so a false ceiling would prove difficult. We tend to keep the doors to these rooms closed and not use them in an evening.
Curtains to close off the bays (ie at the house wall line). I've seen that done before.
As above - get into those loft spaces to insulate them. either create a hatch from the room below or through a wall.
Hive / Nest .... How easy are they to self install?
Fitted a Hive this weekend. My boiler is on the top floor and I had an external timer but no thermostat.
It took about 10 minutes and does the job of both. Really impressed so far.
On the evidence of my thread I'm dead lucky. I can run my 5kw stove for days on end and maintain 25 degrees throughout the house. I even need to open windows to cool it down sometimes. Open plan staircase off the lounge where the stove is just channels the heat up the stairs. Heat seems to circulate really well compared to other houses I've been in where parts remote from the stove get cold. Its a modest three bedroom 1 1/2 storey house.
In summary my secret is house layout, insulation, the right size of woodburner, and of course a good supply of wood. I also have no neighbours so particulates isn't even an issue.
This stuff about keeping the house up to temperature 24h being most efficient is such obvious bollocks I worry about anyone who can repeat it with a straight face.
Elementary physics/engineering dictates that the rate of energy loss is basically proportional to the difference between internal and external temperature. This is obviously greatest when the house is hottest. Allowing the house to cool means that the energy loss decreases. The purpose of heating is to replace this lost energy, nothing more, nothing less. If you measure the temp at night when the heating goes off, it will initially look like a linear rate of cooling but this rate will reduce through the night (depending on specific internal/external temps).
The price you pay for letting the house cool is that it take a bit of time to come up to temp in the morning (you can of course get the heating to come on early if you want). We are typically around 13C when I get up on a chilly winter morning.
I bought a Radfan to get a bit more heat out of our barely coping radiator. Works well, slight fan noise, but we got used to it quite quickly.
i like threads like this because i suffer the same.
ours (1930's) was cold. It would be about 10-12 deg around this time of year. Heating would be on for 5 hours and top out at about 17 if we were lucky. Things ive done to improve it.
New water pump. flushed system several times. this had a big difference. most of the old rads were full of rubbish. the few ive replaced are now significantly more efficient
replaced doors downstairs. we had wooden doors, now composite. this had the biggest effect overall. We can now heat the house and it doesnt feel cold at 18deg
nest didnt do much infact heating costs increased when we tried to use the time to temp function.
we still have a condensation issue though. moisture is about 70% !!!
I had the same problem in my 1910 semi, I could never get it much more than warm, no matter what I did. I moved into a new build last year and I have the opposite problem, I have to manage the heat so the house is cool enough at night for me to be able to sleep (even in the depths of winter).
We're in a 1900 detached, with a 1990s extension adding about 40% more space.
Upstairs set to 18°c on radiators. Downstairs in wet UFH, 20°c through the day, 18°c through night. The UFH takes a while to warm up so it seems cheaper to not let it cool too much.
Two woodburners warm the house up nicely too.
Sounds like your first problem is getting the heating running properly. Insulation will reduce the bills, but the heating should be able to quickly bring you up to temperature regardless - then you can save money later by only heating when you need it.
You mentioned you have microbore (10mm) piping to rads? This is notorious for getting sludged up. Symptoms would be failing to heat house quickly...
Are the rads hot to touch when thermostat demanding heat? Should be almost too hot to touch. Is the boiler burning when the thermostat demands heat? If not (but pump running) this suggests the boilers done all it can heating the water, but until the rads pull heat out there ain’t more heat it can put in the system. If all of that is true I’d start by flushing the system. Either get a pro in or quite simple to do a chemical flush diy with a bit of research
If rads are proper hot this just suggests the rads are undersized, swapping to modern finned rads of equivalent size would help here.
Yep, heating is on 24hrs a day, when the boiler fires is a different question. 23.30 to 7.00 heating is on at 14degree C so boiler doesn't fire unless it's really cold. If i leave the house the heating turns down, if i go home it turns up. But it's always on, in theory
I have to manage the heat so the house is cool enough at night for me to be able to sleep (even in the depths of winter).
This I why I will never buy an old brick/no cavity dwelling, the cost of heating is only ever going to get more expensive, my current property is just about ok with 270mm insulation in the loft and triple glazing, it’s the shoddy 80’s dormer rooves that let the side down (and heat out) with stud/felt/tile construction and a bit of jablite in between. At least it’s dry, draft free and relatively cheap to heat and will hardly ever drop below18.5/19 when the heating is off.
Works well here (modern 5 bed detached). This time of year it comes on around 5am to get it to 20 deg for 0700, and then it’s on and off till about 10pm
No offence but that's piss poor for a modern house.
got to agree tbh
Does sound like the heating system is underpowered or failing in some way.
My employer, Changeworks, has a good guide on insulating older properties, I can email it out to anyone interested (it's on our website too).
Can you measure the temp of your rads?
Our boiler can kick out 75 or 83 to the radiator. 75 is not enough in long cold spells.
it will be beneficial to balance your rads as well. I did it with a little thermometer. worked wonders.
Humidity will make a difference too. The more humidity the harder it will be to heat.
Interesting! I thought I'd read on here it's better to leave it on, so ours is currently on 16 at all times, we boost it for an hour or pop it up to 18 or 20 when we're home. Maybe time to revise that...
Most of the rads are flat double panel with no convectors on the backs and these will all be replaced as we decorate the rooms.
I suspect this will be a significant part of the problem. When we moved into our house almost 8 yrs ago, it had old radiators that were flatt-ish single panels with no convectors on them. They're almost like a large flat panel with some pressed in sections.
Anyway - they were getting hot, but none of the heat actually seemed to radiate out into the rooms.
We got them all replaced & it made a massive difference, immediately.
Given the numbers you mentioned about temp increase with the heating running, it sounds like the heat just isn't getting out of your radiators into the room.
Unless you're going all in with insulation it doesn't make a huge difference in real world terms imho.
2 years ago I had a bit of a mid house crisis and decided to gut our house whilst living in it. Every bit of plaster off the walls and reboardded with insulated plasterboard, new Windows and doors throughout, rewire and re plumb which involved new boiler, rads and controls.
What we've found is the boiler is more efficient but the required heating is still the same, our house will still cool but warms up faster once it fires up. The house (but it's where the stat is situated at the end of the day) will rise 4 degrees in 30 mins in current conditions.
what do you mean by convectors? the wavy sheet tacked onto the panels?
what do you mean by convectors? the wavy sheet tacked onto the panels?
Yep.
Ours is on all year round, we use the thermostat. 19 at night, 20 during the day and 22 in evening. We just leave it a that, its less fuss.
We live in a Victorian semi also, I’m not sure why our house holds heat well. It only dips below 20 indoors when the temp outside is 5 degrees or less.
Might have missed it, but have you checked all the radiators are getting heat, and don't have any air in the top of them?
I say this as i came home from work to a freezing house and a cold girlfriend when we first moved into our rented flat. Quick check of the rads and boiler and all the rads had been isolated with those 90 degree turny valves and a few of the rads needed bleeding too.
We live in a Victorian semi also, I’m not sure why our house holds heat well.
because you keep heating it up?
@cynic-al - if you email the guide over that could be useful (I've had a quick look on Changeworks but I'm struggling to find it....thanks)
Humidity will make a difference too. The more humidity the harder it will be to heat.
Dehumidifier running 24/7 in the hallway (it's a decent Meaco one set to 60 for a 5 bed house).
it will be beneficial to balance your rads as well.
Rads are balanced and bled.
Large open plan kitchen and living room area with underfloor heating.
I leave it on 24hrs a day in the winter with the thermostat at 15C. This keeps the chill off, I might turn it up slightly if the house feels a bit cold. I also have a 12kw stove which we run most nights, this produces enough heat to warm the bedrooms to a comfortable temperature. Like I mention earlier, the house is extremely well insulated, really holds the heat.
You mentioned you have microbore (10mm) piping to rads? This is notorious for getting sludged up. Symptoms would be failing to heat house quickly…
Are the rads hot to touch when thermostat demanding heat? Should be almost too hot to touch. Is the boiler burning when the thermostat demands heat?
The vast majority of the pipework is microbore under the floorboard both upstairs and downstairs. Rad valves/lockshields are a mixture of microbore and 15mm and the new pipework in the kitchen is all 15mm.
Most rads get nearly burny hot to touch, some not so much. I'll flush the system and couple of times and get the rads off the walls and flushed through.
I have two lean-to roofs area on my house. I found the easiest / least 'messy' way to install insulation in there was to go through the roof (slide the tiles up and remove some, cut through felt and remove a couple of battens to make a hatch between the rafters. It was a bit like pot-holing but the difference it made was amazing).
So, back to back readings of two different days:
Two scheduled heating times (6am - 8.30am & 3pm - 8pm) used 14.44 units (starting temp at 6am just over 15degC)
On from 6am to 9pm maintaining 17 degC used 16.37 units (starting temp at 6am 14.9degC)
The top reading was probably a slightly colder day overall despite the starting temp being higher.
I've just been through something very similar to you, we moved into a 1970 house last year. Same temperatures to you, took an age to heat up if at all. Temperatures dropped off pretty quickly overnight. A cold and uncomfortable house to be in.
Changed out the old Potterton thermostat with Hive, made no difference, just more control.
Swapped out all of the radiators from non convector to convectors, increased the size of them where calculations showed they were under sized. I was told its better to over rad a room than under aslong as your boiler can take it and let TRVs control. My boiler was fine and I fitted TRVS to every Rad. Bought a thermometer and balanced the system.
House went from taking about 4 hours to reach temp to about 45 minutes.
We also fitted new windows and doors throughout and Insulated the Loft to 300mm so the heat stays in.
Its a different house now, wife no longer complains....change your Rads now.
Thanks Buzz - sounds like it's time to re-familiarize with BTUs then and find some data on a ~1997 Ideal Mexico boiler!
Ah you have an Ideal Mexico? We do too (of a similar vintage) - we found out that a major issue with these is that the exhaust on them rots through and then clogs it up meaning it doesn't run very efficiently and will eventually start causing the pilot to go out.
These parts aren't made any more so we currently have ours rebuilt with adhesive metal sheet every year when it gets serviced. It makes quite a difference so we tend to do it early Autumn so we get get the best of it over Winter.
Doesn't sound like the only problem you have but worth checking anyway.
Thanks smokey...it's being serviced next week so I'll get the engineer to check it out.
We live in a Victorian semi also, I’m not sure why our house holds heat well.
because you keep heating it up?
You gotta love selective quoting in this please. No, like I said with nothing on it won't drop below 19 until the temp outside gets below about 5 degrees. Then it drops to 18. The lowest I've seen it after a 2 week Holiday when it was on average about 9 degrees in the UK. The heating was on "Holiday" mode (Frost protection), and the house was 17.5 in the hallway when we returned.
your house won't defy thermodynamics.
the heat has to come from somewhere, maybe your next door neighbour has their heating set to tropical...
or maybe its built on a portal to hell?
It is a battle with older houses - I tried the on all the time approach last winter during the cold spells and the house was warm but the bill was horrific. It was a 1920's end terrace with the main external wall facing the prevailing wind, solid brick walls with about 100mm loft insulation and new double glazing (fitted by us).
Certain rooms were really cold and would suffer condensation quite badly so we ended up using electric panel heaters to maintain some background heat. It worked but it added to the sizeable energy bill.
We've since moved to a new build and the difference is so noticeable despite this house being more exposed (we're on the edge of a village).
If you’re gonna do a flush, may as well add system cleaner to the header tank, and ideally install a magnaclean filter too. Let the cleaner run in the system for a couple of weeks, will probably need to flush filter a lot in that time. Then flush and replace with corrosion inhibitor.
Even if you’re not doing this whole process make sure you replace corrosion inhibitor after flushing.
This topic comes up a lot on the screwfix community forum a lot and that’s the standard advice.
19 at night, 20 during the day and 22 in evening.
Are you one of those cold blooded lizard overlords that are supposed to walk among us? 22 degrees! holy hell! 18 degrees feels warm to me, dropping to 16 at night.
Hi, off grid schizophrenic half 1812 / half 2006 build here.
Old bit is solid brick on dirt, gets cold quick esp. downstairs. New bit is usual new stuff, cavity & kingspan, stays warm for ages.
Option #1, "5kw" lounge burner on anthracite. That's sort of a 24hr a day deal, or bust. So, yes, for that one. Lounge gets proper toasty when it is on, which is nice.
Option #2, 20kw central hearing boiler in kitchen, runs on anthracite again. Again, 24hr a day deal, or bust. So, yes for that one too. Radiators are timed though, and are on for the usual sort of pattern, although for longer than usual because the old bit gets cold if they aren't. The kitchen has a few kw all the time coming out the boiler.
We'd love to be able to insulate better TBH but what can be done has been, apart from internal or external wall insulation and that isn't happening.
When we moved in the heating was awful. Most of the front half of the house just didn't get warm, the rads took an absolute age to get heat and even when hot failed to warm the room properly. I ended up replacing most of the rads with bigger panels. Also did a fair amount of re-plumbing to sort the pipework. This helped loads - "oversized" radiators with TRVs works a treat. We still have one room (lounge) that is difficult to heat but it is a stupid layout with stairs on one side and to make it worse, it has the solid brick external walls and the front door. It probably needs an even more massive radiator, or some way to block off the stairs so the heat doesn't waft straight up to the bedrooms.
Since we installed a smart thermostat I've learnt more about how our house heats up and cools down.
In the winter the house takes about 3hrs to go from 18 to 21 in the morning. Overnight it usually stays above 18, the heating comes on if it goes below 16. We were away during the Beast from the East so the geofencing stopped the heating coming on, I watched the heat drop day by day, it got down to 13 after 9 days. Then 5.5hrs to get back to 21. Suprised how long it takes to heat up but equally happily suprised how little heat is lost considering the insulation isn't that great.
Early 90s build, about 100mm of loft insulation (borded on top), insulation blown in to wall, beam and block floor with no insulation (I think quite a bit of heat is lost through the floors.
I used to set our hive to heat pretty much only when me and the wife were home. What I noticed though is that if I keep the house around 17 deg when I’m out that the heating is hardly on. Pops on and off to keep temp up for tiny amounts of time. I Set around 20.5 for when we’re home and from 17 to 20.5 takes an hour or so to get it there. If I left the heating off and the house dropped to say 13/14 deg then from that point the heating was pumping at full power for hours to get back to 20.5.
Now the house always feels warm and according to my gas bill it’s costing me an extra £10 a month which is well worth it for me
Ours is on permanently and just controlled by thermostat, our shifts don't work well for setting timers.
15deg at night or when we're out and 18-20 when in, we don't like it hot at night so works well. Occasionally in the winter it kicks in briefly overnight as the rads are warm. Heats up quickly, but if it's windy the heat disappears quickly.
I have changed all the rads to new convectors, which made a massive difference.
nails in a jam jar of boiler water . If they go rusty then you do not have enough inhibitor and your rads will also be rusty . New rads as they are not that expensive ,and you can fit 1 a month if cost is an issue.
Need to know what BTU's your boiler will produce. Is there a variable speed pump, that might need turning up to move the hot water round a little faster
If you have to run a de humidifier look at where the moisture is coming from, drying clothes in the house on rads , bathrooms with no extraction and wet towels on a rad , plus kitchen . Might sound daft as , but leaving a few windows open to let all the damp air out , then closing them and turning up the heating might be beneficial.
If those red bits are not insulated you don't stand a chance. I would cut an access and get it insulated then patch it up afterwards.
Andrew
I always understood heating controllers / boilers to be binary in that they're ON full gas (sic) until the target temp is reached at thermostat. So does sound like a problem with your system to solve first.
Having said that my latest boiler does (Vailant) seem to have a slower start to getting rads hot and toasty initiallym or if the temp is below but near the target they run warm not hot - So are boilers now throttling performance for max efficiency ?
4 bed new build, dropped to 18c & stayed there all day,.just took 1 hour to reach 22c.
Re: insulation...assuming windows & attic are as insulated as they can be, go for external wall insulation, seriously. We moved from an ex Council 3 bed semi, constructed from shuttered concrete (Wimpey "No-Fines"). Thermally rubbish, very strong but that's about it. Bad condensation caused by cool wall temp vs warm interior. Having EWI was the best thing we ever did to that place. It made a massive difference, so much so that it actually stayed warmer than this 6 months old new build we are now in. Condensation dried up overnight. Check locally, there may be someone offering it. Assuming windows are modern & actually doing their job...(check for drafts, especially opening windows where the foam seals get squashed over time). Replacement seals are cheap enough on line. The heating in the old house was on 24/7, but it was a Heatmiser timed stat. Over 10 years I found the most efficient was only letting it drop by 2 degrees, as it wasn't working like mad for hours to get it back up to temp..