Central heating on all day or Timed?

DorsetDude

DorsetDude

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There is a school of thought that leaving the central heating on low 24 hours is more efficient than having it on for 2 hours in the morning and 6 in the evening and heating the house up from much colder each "burst"

This article has more detail.

So has anyone tried it and can vouch that it is indeed more efficient/costs less?

Also interesting to know if anyone has gone for triple glazing and costs and how well it works both for heat and sound insulation.
 
I think a lot depends on the type/age of boiler as well as prevailing weather conditions. If you've got a new, efficient boiler your home can be brought up to temperature very quickly.

We moved into our house in March 2013 and replaced the boiler within a month. It was "maintained regularly" by the previous occupants but it soon became apparent the house had two temperatures, "hotter than hell" or "bloody freezing", add to that if the boiler was cold you couldn't get it to fire for hot water.

Luckily my brother's a plumber so he fitted a new Potterton boiler with wireless room stat. The stat has 2 modes for programming purposes with a low temp and "on" temp.

Ours is set to 15c for low and 19.5c for on. The on times are 05:00 - 07:00 then 16:00 - 22:00 during the week and 07:00 - 23:00 for the weekend. It seems to work quite well and it's only when it's really cold we have to boost it in between times.

The first month with the old boiler we used £100 worth of gas. Our current combined energy bill is £75 per month which I think's pretty good for a 3 bed semi with solid brick walls.
 
We leave our hot water on all the time but run the heating on a timer. The house is quite well insulated so doesn't cool down too much in the off times. I think good insulation is the key.
 
On all the time. I haven't got a choice though because our house is heated by the Aga and it's burning away 24/7. It's a PITA but lovely to cook on and If the house gets too hot I just open the windows, which it often does because the insulation is nearly 2ft thick in places. I've also just fitted a nice Bullerjan wood burning stove that heats multiple rooms because of the exposed flue that goes through the upstairs landing.
 
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Ours is on for 3 hours in the mornings (Mrs Nod is up at 05:45 and I stay in my pit until about 08:30), a couple of hours at lunchtime (if it's cold enough) then from 17:30 - 21:00. A new condensing (but not combi) boiler about 2 1/2 years ago made a big difference in both confortable temperature and cost terms - our gas bill went down by about 1/3. Not tried the all day thing.
 
Depends on how efficient your heating is and insulation is. The heat loss is going to be the same over a 24 hour period regardless...so you'll need the same energy input to heat it but if you heat it to a higher average temperature I'd imagine the heat loss would be greater due to the greater temperature differential. But the point about damp is an interesting one. You definitely need a thermostat and a decent draught free home to make it work.

I'm getting a Tado smart thermostat to control mine which calculates optimum set back temperatures. The heating is always on but it decides on what temperature to have it when you're not at home. I think that is probably the most efficient as it isn't allowed to get too cold but you aren't heating when you're out or asleep. If it is warm when you wake up it doesn't matter what temperature it was over night. Once it is installed I can see what difference it makes.
 
Russ77 said:
The first month with the old boiler we used £100 worth of gas. Our current combined energy bill is £75 per month which I think's pretty good for a 3 bed semi with solid brick walls.
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Very good. 2 bed bungalow with just me is £100 combined. God knows why. Loft is about 2 foot thick with insulation, double glazing all round.

Saving a 1/3 with a condensing boiler as Nod says sounds intersting but new boiler is about £1500 I had a quote last year.
Wonder if wall insulation would help or not. And replace some windows.
 
DorsetDude said:
Very good. 2 bed bungalow with just me is £100 combined. God knows why. Loft is about 2 foot thick with insulation, double glazing all round.

Saving a 1/3 with a condensing boiler as Nod says sounds intersting but new boiler is about £1500 I had a quote last year.
Wonder if wall insulation would help or not. And replace some windows.
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We've got lots of roof insulation but have found there are some massive draughts in the kitchen. It think the end of the roof/tiles need repointing as the draught(s) seems to come downwards. For now we just keep the kitchen door shut :lol:

The double glazing is pretty old and a little leaky but you only really notice it when it's really windy. Did consider exterior wall insulation but it's going to cost £9K+ and probably around 15 years before we'd ever recoup that. Just not an option at the moment.
 
Russ77 said:
Did consider exterior wall insulation but it's going to cost £9K+ and probably around 15 years before we'd ever recoup that. Just not an option at the moment.
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£9k??!?!? I thought it was about £200
 
Russ77 said:
We've got lots of roof insulation but have found there are some massive draughts in the kitchen. It think the end of the roof/tiles need repointing as the draught(s) seems to come downwards. For now we just keep the kitchen door shut :LOL:

The double glazing is pretty old and a little leaky but you only really notice it when it's really windy. Did consider exterior wall insulation but it's going to cost £9K+ and probably around 15 years before we'd ever recoup that. Just not an option at the moment.
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If the frames are gone then a bit of sealant outside might do the trick. There's also p profile rubber type seal stuff if the windows themselves aren't quite shutting as well as they used to.

My wooden windows are so bad they're now 50% sealant :D
 
srichards said:
If the frames are gone then a bit of sealant outside might do the trick. There's also p profile rubber type seal stuff if the windows themselves aren't quite shutting as well as they used to.

My wooden windows are so bad they're now 50% sealant :D
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I wonder if there's something similar I can use around my front door.
Lovely door...composite of some sort, ...heavy; but hell of a draught along one side!
 
A similar question is radiator temperature setting on the boiler. Do you:

a. Turn it up to almost maximum to faster heat up the house (eg 70 with a max of 75)

or

b. Turn it up just enough (eg. 55-60) to heat the house constantly.

Lower radiator temperature heats up the house slower may even need to be running all the time, but the boiler doesn't work as hard when it's burning. Higher radiator temperature heats the house to temperature faster, but there may be bigger fluctuation in other rooms due to thermostat doesn't reflect the whole house.


Re original question: My central heating is timed. It turns on when we are usually in the house. Because why heat an empty house? The answer will be different if we have a smart thermostat like NEST, I'll set something like 14c when away and comfortable 19c when in.
 
viv1969 said:
I wonder if there's something similar I can use around my front door.
Lovely door...composite of some sort, ...heavy; but hell of a draught along one side!
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Yeh the rubber strips will work fine. I fitted a new door last year and messed it up just before I finished so I became a cowboy and just bodged it with a new rubber strip that was pennies at the local DIY store.
 
CaveDweller said:
Yeh the rubber strips will work fine. I fitted a new door last year and messed it up just before I finished so I became a cowboy and just bodged it with a new rubber strip that was pennies at the local DIY store.
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Thanks. That'll do for me :-)
 
srichards said:
If the frames are gone then a bit of sealant outside might do the trick. There's also p profile rubber type seal stuff if the windows themselves aren't quite shutting as well as they used to.

My wooden windows are so bad they're now 50% sealant :D
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I've added some draught excluder strips to the windows where the seal was obviously brittle & perishing so I think the next step is to address the outside of the frames but it's one of those things where you only really notice it when it's windy and too dark to do anything about it :lol:
 
We run our heating timed.
12am -1am
6am - 7am
4pm - 5pm
That keeps our 3 bed lower villa cosy throughout the day.
We just had new double glazing and door installed which has made a huge difference.

Our combined utility bill per month is £79 (£44 for gas & £35 for electricity)
 
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I'm in with the kids during the day so we have the heating on low all day. The water is on timer and comes on twice a day but we also have a gizmo that diverts excess solar into the water heater so quite often in summer the solar deals with the hot water rather than the oil tank.

We have an oil tank and underfloor heating and the house is always a nice temperature. The solar panels also helped keep the house cooler in the summer which was an added bonus. We also got lots of insulation.
 
onomatopoeia said:
£200 is more like the price of cavity insulation. Exterior insulation is very expensive.
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Ah, didnt realise they were different. How does Exterior work then? Stuff attached over the brickwork or something? Ta
 
Mine runs on a timer to swap between low (15C) and high (19C) temperature, the heating is never completely "off", so if it's bitterly cold outside overnight it will kick in to warm the house a bit. I have it at high for an hour in the morning and from 4pm to 10pm in the evening.

This is the second winter since I had cavity wall insulation put in, which was around about the same time I changed from the traditional dial thermostat to a wireless programmable one, and as yet it hasn't been cold enough out to make the heating activate overnight, -3 is about as low as it has got.

I have the boiler set to maximum for the CH to get the house up to temperature quickly. The boiler modulates the flame so it doesn't run flat out during this process - you can tell the difference just listening to it brining the water in the radiators up to temperature compared to running a hot tap.
 
DorsetDude said:
Ah, didnt realise they were different. How does Exterior work then? Stuff attached over the brickwork or something? Ta
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Yeah, they effectively attach insulating foam panels to the outside of your house and render them.

A couple of places in my street have had it done, they look really good!
 
DorsetDude said:
Ah, didnt realise they were different. How does Exterior work then? Stuff attached over the brickwork or something? Ta
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Basically yes. My brother did a section of wall DIY on a Vicorian terrace he used to live in some years ago.
 
My view is that it's usually better to run for 24 hours. A boiler running for short periods of time to top up the heat is better than starting from cold twice a dat.

However, I think it depends a lot on the amount of insulation.


Steve.
 
It depends on the weather and temperature differential. We have an old stone cottage with 3ft thick walls and a Rayburn in the kitchen. The Rayburn does gravity feed to the HW tank, and we can also circulate that water around the radiators. When the weather is around freezing then I'll run timed (4pm-11pm) but if it turns colder then generally run the circulation 21 hours per day with just a couple of hours off to let the water in the tank get hot for morning showers. When I tried using the same time pattern as usual in very cold weather, not only was the house cold to begin, but I had to really crank up water temperature and that used more fuel than just holding a moderate warmth.
 
We run ours twice a day......30 minutes in the morning to take the nip out of the air and from 5pm until 9pm in the evening..total gas book per month including heating water........ £28.........
 
Hi

We have ours timed most of the time and the wife switches it to all day on occasions, how house is an old very cold Victorian built mid terrace and our combined bill is about £100 a month.

A 92 year old we know who has hers on 24 hours a day 7 days a week and lives in a 30's built mid terrace and her monthly Gas bill is around £175.

Our boiler is a more efficient modern design, hers is a 50 year old item that looks like its come from an old industrial boiler house, its so big.

There is loads of anecdotal information supporting both options.

Paul
 
I just turn mine on when I feel cold and turn it off when I feel warm. There is a temperature dial on the boiler which governs the water temp in the system so I fine tune the radiator temperatures it by adjusting this.
 
This dial on the boiler that adjusts the radiator temperature, this also affects how hot the water will get in the hot water cylinder presumably? i.e it can only get as hot as the water being fed to it(and through the spiral heating tube inside) by the boiler?
I could happily stand my radiator temperatures being lower but the hot water in the shower is only just hot enough with the boiler dial on 75% of max so I'm assuming I cant turn it down to 50% or 25% for example.
 
Some boilers have independent controls for hot water and radiator temperature. Mine doesn't. The hot water is full blast no matter what.

The flow rate will also affect how hot a shower can be as well. You may find dropping the radiator temperature makes no difference and the hot water will be the same regardless.

Just noticed you have a tank... ooops! Yes yours will be dependent on what the tank is set to.
 
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I have a 42Kwh Worcester Bosch combi boiler so hot water is always available on demand.

Heating-wise I leave mine on all day and night but regulate the temperatures via the wireless room stat that allows around 6 time settings.

It starts at 0700 until around 1000 at a temp of 19. It then drops down to 17 until around 1430 when it goes back up to 19 until 2130. Then it drops to 15 for the night.

Cost wise it isn't cheap - around £280 a month for gas and electricity. Mind you, with the old Glowworm boiler we replaced a couple of years ago, we were paying £479 a month!
 
DorsetDude said:
This dial on the boiler that adjusts the radiator temperature, this also affects how hot the water will get in the hot water cylinder presumably?
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Not with ours- that's what a three way valve is for and the thermostat on the tank- we don't have a combi though
 
Tado seems to be working quite intelligently so far. Will be interesting to see what the average gas use will be. I'm not sure I care though as it is nice to be warm but not too warm without any effort at all :)
 
DorsetDude said:
This dial on the boiler that adjusts the radiator temperature, this also affects how hot the water will get in the hot water cylinder presumably? i.e it can only get as hot as the water being fed to it(and through the spiral heating tube inside) by the boiler?
I could happily stand my radiator temperatures being lower but the hot water in the shower is only just hot enough with the boiler dial on 75% of max so I'm assuming I cant turn it down to 50% or 25% for example.
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That's why I always have a couple of hours 'off' on the radiators before we get up in the morning - if your system is like ours, the water going round the tank spiral is affected by the radiators which cool the water, and it doesn't get warm enough.
 
Craig1912 said:
Not with ours- that's what a three way valve is for and the thermostat on the tank- we don't have a combi though
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:thinking: Im getting confused. Surely all the 3 way valve does is decide where to send the hot water thats coming from the boiler: to the hot water tank, to the radiators, or both. The dial on the boiler will determine the temperature of said water boiler is providing.

ancient_mariner has a point about why my hot water may not get hot enough when its really cold in the house. So doing the hot water before (say 5.30am to 6.30am) setting the rads to come on (6.30am -8am) could help that, as long as the hot water tank is insulated well. Which is another game altogether. I suspect mine isn't. Theres also a few exposed copper pipes in the airing cupboard which get hot, wonder if its worth getting some of that grey foam pipe lagging stuff and putting over those or not.
 
I'd suggest running the rads until 2 hours before you rise, then off until you finish ablutions. The house will normally stay warm *enough* in that time & a fan heater in the bathroom provides the extra warmth required briefly. If you turn the rads on while using hot water it can actually cool the water in the tank appreciably except for the top third or so.
 
ancient_mariner said:
I'd suggest running the rads until 2 hours before you rise, then off until you finish ablutions.
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Even with the thick loft insulation my house would be freezing again after that time.

The house will normally stay warm *enough* in that time & a fan heater in the bathroom provides the extra warmth required briefly..
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I do have a fan heater in the bathroom, had one fitted last year. Use it all the time

If you turn the rads on while using hot water it can actually cool the water in the tank appreciably except for the top third or so.
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when you say turn on, you mean when the programmer turns the heating on. Interesting. Surely though if the hot water cylinder is up to temperature, then the demand for heating comes on, the three way valve would only let the water round the heating circuit, so why would the cylinder water get colder?
 
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Keeping it low all day has been proven to work as it is the 'getting the nip out of the air' that puts the boiler under heavy load.

Also insulation is all well and good but if you end up with condensation problems, opening the window undoes all the efficiency stuff. Plus on occasion you might actually want to open the window. (Cooking, bathrooms etc).

External insulation.....can be shown to be more efficient but retrofitting usually creates something visually appalling and also changes the dew point in the wall which has a knock on effect on the condensation issues. Far more complex than most people believe and not fully understood by many in the industry, although the big bucks to be earned from such ventures usually mean they will have a pretty graph to show you that their idea is the best thing since sliced bread. Until next year, when research will tell you margarine is better than butter.
 
DorsetDude said:
when you say turn on, you mean when the programmer turns the heating on. Interesting. Surely though if the hot water cylinder is up to temperature, then the demand for heating comes on, the three way valve would only let the water round the heating circuit, so why would the cylinder water get colder?
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I don't have a 3 way valve, however if your 3 way valve isolates the tank from the radiator circuit then your HWC should stay warm.
 
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