On Sun, 17 Oct 2004 12:12:43 +0100, "Ed Sirett"
wrote:

On Sun, 17 Oct 2004 09:25:19 +0000, Dave£ wrote:


A couple of times recently, the hot taps have been running cold, and
the combi boiler doesn't fire up when a hot tap is turned on in the
house.

I've also noticed a lot of air pockets blasting and sputtering from
the hot taps when thy are first turned on. The unheated water from the
the taps seems to be at a pressure high enough that would normally
cause the boiler to fire up - but the water is coming out ice cold.

The central heating is working fine.

The boiler is a Britony Combi 80 made by Chaffoteaux et Maury.

Anyone tell me what the problem is?

Many thanks,

For sure this is the HW flow sensor. I'm 99% sure this is implemented using a
differential pressure diaphragm on this model. The diaphragm has split or
the pin it move has jammed. Just possibly the microswitch it turns on has
completely failed.

Thanks for that. That item was high on my list of suspects. This
boiler doesn't seem to have a diaphragm such as you mentioned, but I
have found the switch which I think you are talking about. I took it
out of its hosing this morning to look at it. after removing the
spring clip, I pulled it out an some hot water sprayed out for a
moment. Looking at the switch, I see a brass plunger, about 3 or 4mm
diameter. one the exposed part of the wsitch are two eires going to
the control box. Is that the switch you are referring to?

Is there a way to test it - like with a volt meter perhaps? And if it
proves defunct, is there a way to fix it - like cleaning some contacts
inside, perhaps? I was going to replace the whole item today just in
case it's faulty - but all the plumber merchants are closed, and
tomorrow I'm supposed to be going away.

Thanks

Dave L