2 CH questions

[Jethro]

Hi all

We have currently 8 rooms-size rads (in a bungalow) on our Vaillant Turbomax combi. SWMBO would like 2 extra rads ... a little one in the porch, and a little chromey ladder one in the spare loo. Am I right in thinking the boiler should be able to power two more rads OK ? As for fitting :

1) switch off boiler 2) drain CH 3) tap in, and fit plumbing 4) re-fill system. & bleed 5) check for leaks 6) ensure lockshields are tight 7) start up 8) bleed 9) check 2 new rads are getting as hot as the others by judicious opening of the lockshield. 10) drain a bit 12) add inhibitor 13) go back to 4 and check again

(9) is an idiots understanding of CH balancing.

The system is 2 years old, and had inhibitor

advice gratefully received

[mike. buckley]

In message , Jethro writes

On the subject of draining - is it common not to have a drain point? My system doesn't seem to have one and I've had to do the best I can with a bit of hose. I'm blaming the previous bodging owners (4 spurs off one socket - grrrrr)....

[Set Square]

How long is a piece of string? Your question is impossible to answer without adding up the outputs of all your existing radiators, and comparing the result with the boiler output to see how much spare capacity you have.

Having said that, if the boiler has been spec'd to give a good hot water flow rate, it probably has more than enough capacity for the CH - but you can't be absolutely sure without doing the sums.

As for fitting :

That's basically it. Depending on the pipe layout, you may be able to isolate the section where you're connecting your additional radiators without draining the whole lot, and losing all the inhibitor.

There's a bit more to it than that! Adding new rads will change the flow to the existing rads to some extent, so you may have to adjust some these too in order to get the balance right. Aim to get the same temperature drop across all the rads.

[Phil Addison]

You could try the FAQ, or alternatively read the FAQ, and failing that there is always the FAQ as a starting point.

By the way, see the FAQ.

The system is 2 years old, and had inhibitor

Err.... the FAQ?

Phil The uk.d-i-y FAQ is at

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