gas usage by hot water query

Cardew

aay1987 wrote: »

so will a thermostat of 4 will consume less gas to maintain a temp of 25 degree? when we compare it to a thermostat of 2? i.e. say between 1pm and 11pm?

is that the case with hot water aswell? say while having a shower we reduce the thermostat to 2?is that saving any gas had i left the thermostat on 4 for the shower?

so why do they say using low thermostat lowers your gas consumption.

I assume by 'thermostat of 4' you mean the setting on your combi boiler?

That simply increases the temperature of the water that the boiler produces.

If you have the room temperature set to 25 degrees, then that largely determines how much gas you will use and the temperature of the water set on the boiler will have little effect on economy. The lower the water temperature, the longer it will take the room to get to the required temperature as the radiators are not as hot.

Generally the hotter the water the boiler produces, the more efficient it is, but it is fairly marginal.

For the shower hot water, it largely doesn't matter what the water temperature is set to on the boiler. If you like the shower water to be at, say 40C, you will mix cold water with the hot water that is produced at, say, 70C.

Set the boiler to, say 60C, and you will use more hot water to maintain the same flow at 40C. but the boiler will use less gas to heat the water to 60C than 70C.

The nett result is roughly the same amount of gas used.

notbritishgas

aay1987 wrote: »

cheers notbg. you said you have a combi boiler. do you have ur eco button on? it if for pre heating. what does it mean? anything to with using less gas?

No sorry aay I have a normal condensing boiler, not a combi.
I have done a bit of googling and it would appear that the eco button may turn off the preheat facility for the hot water (on the Worcester Bosch). I presume this facility keeps some hot water somewhere so you get instant hot as soon as you turn on a tap, but I do not really know.
What make of boiler have you got, does the handbook help?
If what I say is correct then activating the eco button should save you some gas.