combi boiler

[rbrad]

hi could anyone please advise , i have a worscester 40 he combi , its oversised as i wanted a good water flow rate i could manage with a 30 kw , what water flow rate would this give me compared to a 40 , im only thinking of changing as i think the 40 uses more gas than a 30 to heat up a 4 bed semi , will changing to a 30 save me 25% on gas usage or does it not work like that , is ther a straight forward way of finding out how much gas each model uses per hour , thanks rob

 

[HERTS P&D]

It will cost you more in buying a new boiler and having it fitted than any saving you would make.

Andy

 

[dcawkwell]

Unlikely to save much at all. The big boiler will still modulate down
to meet demand. Perhaps not quite as low as a smaller boiler.

Save your cash and buy more insulation.

 

[Agile]

You only pay for the gas used!

The gas used depends on the heat you are taking from the boiler so it will be the same regardless of which boiler you have.

At part load the 40 kW is probably more efficient as the heat exchanger is larger.

Tony

 

[mcmoby69]

has the heating output been adjusted correctly?

 

[rbrad]

has the heating output been adjusted correctly?

thanks for getting back , sorry for my ignorance but how do I adjust the heating output and what should it be set at cheers rob

 

[mcmoby69]

should have been done when comissioned. you need an RGI to do it. might as well get him to service it at the same time.

IMO it is not a DIY job