If we've currently got an 8 year old Potterton Combi 100 boiler (which
I believe is specc'ed as a 100btu boiler), and which when working
supplies the house fine with heat and hot water, is there any reason
why I should go any higher than a 30kwh boiler as a replacement?

Looking at the WB Greenstar 30CDi at the moment, but noted that their
"calculator" often suggests a 37kwh option instead.

What's the tangible benefit (if there is one) of getting a combi
boiler which supplies over-the-top power?

Matt

wrote:

What's the tangible benefit (if there is one) of getting a combi
boiler which supplies over-the-top power?

Better flow rate of hot water. The extra 7kW would give you another 3lpm
of hot water, or a 30% reduction in the time taken to run a bath.

As long as the heating side can modulate over a decent range, then there
is no real down side to having more power as long as you gas supply has
the capacity.


--
Cheers,

John.

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On Sun, 17 Aug 2008 22:19:06 +0100, John Rumm wrote:

wrote:

What's the tangible benefit (if there is one) of getting a combi boiler
which supplies over-the-top power?

Better flow rate of hot water. The extra 7kW would give you another 3lpm
of hot water, or a 30% reduction in the time taken to run a bath.

As long as the heating side can modulate over a decent range, then there
is no real down side to having more power as long as you gas supply has
the capacity.

It is also possible that the existing unit is _effectively_ operating at
nowhere near the nominal 30kW rating. So that a similarly rated but nnew
unit would give a very noticeable improvement.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html