Central heating filling loop

[D.M. Procida]

Our Baxi 105HE combination boiler -

- has a variety of connectors, some with valves on the pipes.

It looks like this (not a brilliant picture, sorry):

If I understand it correctly, those taps represent left to right:

• heating out

• hot water out

• gas in

• cold water in

• heating return

It's apparenly supposed to have a filling loop, a temporary connection between two of them for repressurising the system, but I can't see one right there.

However, further down and mostly hidden behind a cabinet panel is what might be a section of braided pipe with two valves on it, possibly connected between cold water in and heating return.

Is that the loop I should have?

Daniele

[David WE Roberts]

"D.M. Procida" wrote in message news:1kr17r2.1k1zaasyr4rk9N% [e-mail]...

Can't say for that model of boiler, but yes you should have a connection with isolating taps (and a non-return valve I assume) which allows you to connect the cold mains to the central heating flow or return. You use this for the initial fill and for any subsequent repressurisation.

[Phil L]

Yes. Open the valve slowy and watch the pressure rise on the indicator, don't blast it open, just allow it to re-presurise slightly above what it should be, then turn it off, the pressure will fall slightly.

My valve was knackered so it got replaced with a brass stop-c*ck. On some models of boiler it's a fiddly piece of plastic (WB most noticably) which has to fit into a (usually inaccessable) socket underneath the boiler.

[Halmyre]

Our servicing engineer used to point out that the loop shouldn't be left pe= rmanantly connected, but I don't think they've bothered about it on the las= t few services.

We onc estayed in a holiday cottage where the filling loop was nowhere near= the boiler - it was in a cupboard with the hot water storage tank. This ca= used a bit of bother when I had to bleed all the radiators and then couldn'= t repressurise the system. Oops.

--=20 Halmyre

[D.M. Procida]

permanantly connected, but I don't think they've bothered about it on the last few services.

I presume that would be to prevent the system emptying into the mains.

Daniele

[Chris J Dixon]

Yes, but that would only happen if the double check valve, which is a mandatory part of the installation, failed. It is belt and braces.

I would guess that, around the country, very few loops are actually disconnected when not being used.

Chris