Programmable Thermostat

[XtraRaptor]

We have just had our boiler changed and the new boiler has a programmable thermostat fitted, we have thermostatic valves on all our radiators.

So I'm after some advice, I can now program temperature as well as on/off times for the heating, so is it better to have the heating running 24/7 but reduce the temp overnight and when we are at work, or just switch on and off as we used to. Also what temeratures would you recommend during the "off" periods.

 

[D_Hailsham]

If the stat has an 'off' switch it will probably put it into 'frost protection' mode. This means the boiler stays off unless the room temp drops below about 5C.

I keep the heating running 24/7, but the overnight temperature is set to 5C, so the boiler never comes on. The house is well insulated so the internal temperature never drops below about 13C, even in cold winters when it is -7C outside.

Start with overnight temperature at about 5C and increase if necessary. Do the same for when you are at work.

If your new stat has 'Optimization', turn it on. It will automatically adjust the turn on time according to the weather. You set the first 'on' time to when you want the house to be warm, e.g 7.am when you get up. On some stats it will do the same when you return from work, i.e bring the boiler on before the time you set, e.g 6pm, so the house is up to temperature by then.

PS A Max/Min thermometer is useful for monitoring temperature variation.

 

[Charnwood]

When we had a decent prog-stat (Honeywell CMT907) I set the nighttime temperature at 16°C so her dog didn't get too cold on winter nights. The other 5 time zones were set for the humans.

 

[DP]

Raptor, my progstat has 6 changes. The room it is fitted in has a design temperature of 18. If the temperature drops below 18, when I am at home and not in bed, I will want the heating to kick in and maintain 18 degrees in the hall. Settings as follows- arise at 7 so 6.30 is 19, 7 am 18. Leave house around 10 so 9.30am reduce to 12. Return at 5 so 4.30pm 17/ 16.5, watch box at 7 so 6.30 up to 19/20. In bet at 11.30 when stat drops to 12.

If the hall ambient temperature is above 18, boiler stays off.

If I am active round the house and am not sitting down or getting out of bed in the morning, I will probably be happy with hall being at 17, 16.5 even, thus saving fuel

Ambient temperature is dependant on external temperature and activity in the house (gas fire running, many cakes being baked in the kitchen, cold and sunny outside but calm day heats internal space)

If a system is well designed, when hall is at 18, living room should be at 20, batrooms at 16 and bathrooms at 25

 

[Charnwood]

18/19 to get up to in the morning? Brrrrr.

I'm not sure how bedrooms would be 25 if the stat in the hall is set to 18.

 

[Galoka]

What temp you find comfortable seems very much down to habituation (within limits), as well as personal physiology, activity, age etc.. Our basic indoor temp is 18C or so. and I find that fine. Sitting her in the kitchen with a T shirt on. If I go to my parents house it always seems sweltering. But it also varies during the day, Probably a bit warmer in the sitting room on an evening,

It's quite possible to get some of our rooms a lot hotter, whilst the base temp is 18. Our room stat is in the hallway/. it has 3 external doors, a stupidly large and lovely single glazed window, and even with all the effort, it's still a bit drafty. so it is by far the coldest part of the house.

 

[Charnwood]

I have a nesh wife, so we have to have the temp at the low 20s.

http://en.wikipedia.org/wiki/Nesh

 

[Galoka]

I have a nesh wife, so we have to have the temp at the low 20s.

http://en.wikipedia.org/wiki/Nesh

Not heasr that word for a while

Sorry, I wasn't meaning to sound like I was judging someone's else's choice of temperature. People should run it at whatever temp they find comfortable or they need. We are all different

 

[DP]

Charnwood wrote

I'm not sure how bedrooms would be 25 if the stat in the hall is set to 18.

Batroom (should read bedroom is 16 NOT 25, but bathroom is )

The temperatures are based on someone sitting down and calculating heat losses for the rooms. Bedroom would have a design temperature of 16 and heat loss of 17 degrees C would then give a size that maintains that temperature when hall attains 18 where that radiator is also based on heat loss, now of 19 degrees C. When the heating kicks in, hall gets to 18, bedrooms 19, living room 20 and bathroom (unless a ladder type rail fitted loaded with towels) 25 degrees C.

 

[Charnwood]

Sorry. I read batroom as batHroom and missed the bathroom following.

 

[XtraRaptor]

Thanks for all the replies and info, our stat is in the hall (if it is returned to its holder) and I'll set our temps as you have suggested and will see how we go.