Efficient boiler use

pjc16wg

We have a 3 year old A rated condensing boiler. The temparture of the water heated by the boiler can be adjusted. We have thermostatic valves throughout the house.

Now that the weather is getting warmer the boiler does not have to work as hard when we require heating. My question to all MoneySavers is this:

Is it more efficient to run the boiler at maximum temperature - in which case any required heating target temperature will be reached quickly, and the boiler shuts off; OR

Is it more efficient to run the boiler at a lower temperature - but inevitably for longer.

Any thoughts?

Thank you:)

pimento

Can you not just turn down the thermostat?

House_Hunter

Have been thinking the exact same thing!!

Our condensing combi is a 30kw version. By my reckoning it depends on how low the boiler power can modulate. If even at lowest setting (say 3kw) you are still wasting energy/heat; then it would be more efficient to run it hotter for shorter.....

My plumer did tell me "they are most efficient when running hottest" though not sure if thats true or not...

macman

House_Hunter wrote: »

Have been thinking the exact same thing!!

Our condensing combi is a 30kw version. By my reckoning it depends on how low the boiler power can modulate. If even at lowest setting (say 3kw) you are still wasting energy/heat; then it would be more efficient to run it hotter for shorter.....

My plumer did tell me "they are most efficient when running hottest" though not sure if thats true or not...

Efficiency does not equal economy. Your boiler may well be more efficient at turning gas into heat when at a higher temp, but it'll still use more of that gas to produce the higher temp.

ormus

when the engineers designed the boiler they made it so that it is most efficient at a certain point. ie at its normal/usual operating point.
in practice that generally means in the middle of its operating range.
all engines do the same thing. they are inefficient either side of that point.

ie
your car uses approx twice as much fuel at 100mph compared to say 55mph.

House_Hunter

OK...so the question therfore is;

What uses least gas?

Running a boiler at high temps (more efficient, but more gas) for 1 hr?

or

Running a boiler at a lower temp (less efficient, but less gas) for say 2hrs?

I suspect the answer is probably...it depends...

I persoanlly turn my boiler temp down a "tad" during spring and autumn and have it turned up higher during winter.


...of course this is in addition to adjusting TRV positions.