On Sat, 04 Nov 2006 10:59:47 +0000, visionset wrote:


"Ed Sirett" wrote in message
news

The purpose of TRVs is mainly to prevent certain areas becoming
over-heated. They have the fringe benefit that, eventually, provided the
system is adequately powered, the system will be balanced even if it
wasn't beforehand.

Ideally the system should be balanced initially with the valves off (or
set to max).

Yes that was the intention hence the reason the TRV's are removed at
present.


Many combi models simply have a standard 3-speed pump motor set to max.
The better models and more recent models tend to have the pump speed
adjusted by the boiler's controls. This means that as the required output
power falls the pump power can be reduced. The effect is to greatly reduce
whistling. Different models seem to be more or less prone to whistling and
amazingly the market leader is, IME, one of the worst.


Mine is the probably the one of your 'IME' a Vaillant (ecotecplus 837) since
I know you
tend to fit these.
I'd not read that anywhere in the archives.

Sorry I think the Pump on the latest Vaillant is varied.
I meant to say different models of TRV and the Market leader is Dr*yt*n
isn't it.

Setting a lower pump speed on many combis will simply reduce the HW
production rate.

I've set the speed through option d19 to speed 1 for the heating. So you
think I should put it back to
the default speed 2?


Removing all the TRVs is against the spirit of the building regs if not
the letter.

Like I said it's only while I'm assessing the current situation.

So what I've said rings true then?


HTH

Thanks Ed!
--
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
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards