Help with heating costs/combi boiler settings

kayjay1809

Hi, I hope someone can give me some advice on how to get the best out of our combi boiler.

We have a Baxi Combi 105 HE, fitted approx 5 years ago along with radiators with thermostats but no room thermostat.

I know it sounds ridiculous but we don't really know how to use it for the best value. There are two dials for heating and hotwater, which can be turned from "12 o'clock" (the lowest) to "9 o'clock" (the highest). My husband insists on keeping them at 'quarter past' and no higher. But the instructions say for normal winter use, to have the heating one on full.

We're with NPower for both electricity and gas as is my neighbour. She has her heating on full and her thermostat set at 25C but her bills are lower than ours! She has a stone cottage (three floors) whereas we have a dorma bungalow (we had cavity wall insulation fitted last week).

I have no idea why we don't have a room thermostat, it was never suggested to us but the main room has a log burner so I'm assuming it wouldn't be a good idea in there anyway.

So do we (a) have the heating turned high and the radiator thermostats low or do we (b) have the heating dial turned low (at quarter past) and have the radiators higher. We normally have all the radiators at 3 which is the middle setting.

Any advice welcomed, thanks in advance.

HappyMJ

The higher you set the boiler the quicker it gets to temperature and the less time it needs to be on in advance of the time you need to use the room then the less it costs but not by much. If you use the log burner I wouldn't use the central heating whilst you are using the log burner. I'd only use the central heating late in the evening to warm up the bedrooms before you go to bed and in the mornings to heat the bedrooms as you wake up.

macman

Set the DHW and CH stats on the boiler to about 6pm and experiment from there.

spinningsheep

I have a Baxi DuoTec combi which by the looks of things, bar the digital temp readout is virtually identical in controls. We have the hot water set at about 20-15 past which is plenty hot enough, and the heating one I have set about the same for 57-58 degrees, half past for 60-63. Never really needs to be above that. All condensing boilers do not fully condense unless your return temperature on the heating water is 55 degrees or below, so the lower the temperature on the boiler the more efficient it will be running, but macman is right, the house will heat up far faster if you have the boiler set at a higher temperature, but you may well use more gas as a result. Experiment. Set the boiler low and see how long it takes to heat up. I change my setting according to the weather ie higher 60+ if it is sub zero outside, 57 or so if the weather is milder like now.

kayjay1809

Thanks for your replies. I had a plumber out today to service the boiler and he has got it working to 97% efficiency apparently. He explained how a room thermostat would work and quoted £120 inc labour for a remote one. I think we'll be able to afford that by Autumn but for now he said our gas usage should go down a bit now our boiler has been cleaned as it was desperately in need of a service. Our 'heat up time' is very fast now, it's definitely improved. So I think a thermostat would save us money, but will have to wait until we can afford it.

HappyMJ

kayjay1809 wrote: »

Thanks for your replies. I had a plumber out today to service the boiler and he has got it working to 97% efficiency apparently. He explained how a room thermostat would work and quoted £120 inc labour for a remote one. I think we'll be able to afford that by Autumn but for now he said our gas usage should go down a bit now our boiler has been cleaned as it was desperately in need of a service. Our 'heat up time' is very fast now, it's definitely improved. So I think a thermostat would save us money, but will have to wait until we can afford it.

97% efficiency of what? 97% of the original efficiency? I suppose for a boiler 5 years old that's not too bad.