House not warming up!

Dave_save

quaium wrote: »

So I guess I'll have to check the loft and try out a thermostat program to see if things improve.

One final (so he says) question... when the radiators are warm and the house isn't warming up what is the problem more likely to be, the loft insulation or ineffective use of the thermostat?

Just an example of how effective loft insulation is. Last winter my loft was fully insulated with about 150mm of good quality insulation. During the cold snap in February the bedrooms would never get above 14C. In the summer I increased the insulation by adding another 170mm. The difference is amazing. The bedrooms are now getting to 17C/18C very quickly, even in temperature conditions of -5C outside.

notbritishgas

quaium wrote: »

So I guess I'll have to check the loft and try out a thermostat program to see if things improve.

One final (so he says) question... when the radiators are warm and the house isn't warming up what is the problem more likely to be, the loft insulation or ineffective use of the thermostat?

As long as you have programmed the thermostat for the temperatures you want at certain times of the day then the fault does not lie with the thermostat.
Could be one of the following (most have been covered earlier):

Boiler not big enough to deliver the heat required for the number of radiators.
Temperature of the boiler set too low.
Very poor insulation of the house.
Outside temperature so low that the boiler cannot cope.

Just to give an example, when my heating has been on for about an hour I can only put my hand on a radiator for about a second.
Also last week when the outside temp was minus 7 and did not rise above minus 5 until lunchtime my living room did not get to 21 degrees til mid afternoon, my programmable thermostat is in the living room.

Biggles

The problem is that you don't let the thermostat do your work for you.

There's no way a house, after being allowed to drop to 14°C or below during the day, is going to be snug and warm all evening. Not even by bedtime in fact, in this weather.

You need to experiment, but I'd be inclined to have the background temp during the day at 16°C at least, rising to 20°C or so a couple of hours before you get home. And, no, it won't 'be on continuously' as you suggested earlier. It won't be on at all to begin with (assuming you have the house warm for getting up in the mornings), then it will run occasionally to keep the temperature from dropping below 16°C.

And this weather, you need the boiler temperature set to whatever is the highest recommended setting. Set it a bit lower when the outside temperature rises again, but you need hot water in those pipes right now.

quaium

Thank you everyone for all the advice, it's very much appreciated. I will try a week of programming the thermostat and see what affect that has. I will also be checking out the loft to see if it has been insulated well and if not get that insulated as soon as possible.

quaium

Okay, I couldn't wait until the weekend to check the loft so have looked at the Home Information Pack and and looks as if the loft has pitched 75mm loft insulation. Doesn't mean anything to me but it's nowhere near the recommended 250mm.

Do I need the loft insulation topped up?

macman

Yes, 270mm is the recommended depth. 75m is completely inadequate, so I suggest you get some more down this weekend.

Biggles

In fact, 75mm is probably OK for pitched roof rigid insulation boards (if that's what you've got), which are quite different from fibreglass blanket insulation.

In any event, the temperature difference you are suffering is too great to be accounted for by a little lack of insulation.

My old house is single-glazed, with fibreglass loft insulation of 100mm at most, and draughts coming in at every door and sash window. But my 25-year-old boiler has no problem keeping the temperature up as long as I program it accordingly.

Yes, you will use plenty of gas at this time of year. But that's what having central heating in cold weather is all about.

I think a little tinkering with the programmer, not letting the temp drop too low during the day, and making sure it starts up early enough mornings and evenings, is all you need.

Bear in mind that it can take several hours to raise the temperature of a house just a few degrees (after a holiday in the winter, it takes at least 24 hours before the house reaches anything like a normal temperature); the problem is the fabric of the building itself, which takes a long time to warm up. You may have been expecting it to respond too quickly.