Turn Your Thermostat Down . . Or Do You?

Regulo · January 15

I've been thinking (Oh, no, not twice this decade, I hear you say). Save money and turn your heating thermostat down by 1 degree. That's what the general consensus of the energy conscious tell you. So, how does that work? Let's say you set your 'stat at 21C. When that is reached, your boiler(or whatever) switches off. The temperature falls to 20.8 for example, and the boiler comes back on to raise the temperature back up to 21. The cycle repeats, until you turn it off. So, if you now set the 'stat to 20, the same cycle will occur, but between 19.8 and 20. The boiler runs exactly the same way, using exactly the same amount of fuel . . or does it? The only saving, as far as I can see, is that on start up it won't take as much energy to reach 20 as to reach 21. Where am I missing something? Apart from up top.

Meantime · January 15

The warmer the inside is, the greater the differential between inside and outside and the greater the heating loss or transfer. So heating set to 20 might come on every 60 mins and take 20 mins to get upto temperature. Heating set to 21 might come on every 55 minutes because room will lose the heat quicker and might stay on for 22 minutes. At 23 it might come on every 45 minutes and stay on for 25 minutes etc.

The house and all the furniture in it are one big heat sink, which is why when you have been away and come back and put the heating on it takes so long to get warm and will cycle on more frequently as the building core reabsorbs heat lost whilst the heating was off for an extended period.

Bluebell · January 15

So, in danger of thread drift, what’s the answer to the age old question, is it more economical to leave the heating on low 24/7 or on high(er) twice a day?

floydraser · January 15

2 hours ago, Meantime said:

The house and all the furniture in it are one big heat sink,

Thank you MT, I'm going to have that printed onto a T-shirt, no, on second thoughts, a winter fleece, for Mrs Raser!

rightsaidfred · January 15

No expert but logic tells me keeping topped up once it's on has to be better than starting from cold a bit like the argument for leaving a light on against the surge of switching on and off.

I may not be the best judge here as the priority for me is comfort over cost.

Fred

Smoggy · January 16

We leave the heating on at a low level all year round, in summer it does nowt except run the pump once a day for a few minutes to prevent seizing, when it gets cold it runs at a low level (16 in the day 18 in the evening) to encourage us to light the fire as apart from the odd pint we've not paid for wood in the 10 years we've had it, all rooms have thermostatic valves and the non lived in ones are at just above frost stat, even bedroom is only on 1 as fire is below and chimney runs up giving heat long after the fire has gone out.

Bathroom rad gets turned up before a bath or shower and back down afterwards.

floydraser · January 16

I think we take heating for granted until it gets cold.

I looked into this when the gas prices started to rocket. When we were working the base temp was 15C but went up to 19C from 6.30 to 8.30am. Then 19C again from 5 to 9.30pm. Now retired the morning is set 7 to 9am. During the day we have to put some decent clothes on or get our a**es moving somewhere; the telly stays off! If we do stay in we just boost the heating up as required.

We sometimes go to auctions and see people sitting there without bidding. My wife comments that they only go so that they don't have to put the heating on at home.

When I was working and getting home very late I bought an electric greenhouse heater for our smallest bedroom where the PC is, to save heating the whole house. It's still here like an old friend and it had a second life during lockdown when I worked from home.

Hot water again, we take for granted until fails. Our conventional system is of course designed for four people, with a huge copper tank. The tank in our caravan is 13 litres and that's enough (without a bath) which is why I installed one of similar size in the boat. At home we heat the water for an hour in the morning and again early evening and that's just about enough but again, it's boosted when needed.

Attic is insulated, cavity walls were done for free a while ago but one of the best things we did recently was to put a curtain up on the inside of the front door. Our porch area has always been cold and we were advised to put a radiator in there years ago, which we did. It made a slight improvement but it was never satisfactory. I lined the services cupboard with polystyrene foam to little effect but fitting the lined, swinging curtain has made a huge difference, even though the front door a upvc insulated jobby. A bit old fashioned but so what.

addicted · January 16

We bought our present house as a new build in 2004 and it's insulated to within an inch of it's life! During the winter we are mostly at home all day. The heating comes on at 7.00am and goes off at 9.30am, then again at 4.30pm and goes off at 8.30pm. The thermostat is set at 22deg. The hot water comes on for 20mins at 7.00am and at 5.00pm. we often turn the heating off during the evening as it frequently gets too warm . all internal doors are invariably left open.

Carole

Smoggy · January 17

Hot water wise we confuse plumbers as we have a hot water cylinder and a combi boiler, there's a set of thermostatic valves between so if the cylinder is hot it goes direct to taps, if its warm it goes via boiler to taps.

Reason being we have solar panels and at the time it was the only viable energy storage option as export rate is just guessed at 50% by ofgem with no meter so we just run the immersion all the time, we keep a spreadsheet with leccy/gas/generation meter info and it seems fine, for quite a while we were getting more back in fit tarrif over the year than we spent in gas and leccy, and when they finally force a smart meter on us there's a spare heating coil for thermal solar if I can make a frame for the end of the house.