Very hot radiators; cold water

[rhodes]

In the last few days, our boiler (Chaffoteaux & Maury Britony Combi) has been acting strangely, in that it has been reluctant to heat water. The radiators are working fine - if anything they are hotter than before. In the last few days, we simply turned the tap off and tried again, and it usually worked, but from this afternoon, there is no hot water at all.

We have checked and double checked and triple checked the manual and so on, and the boiler is definitely set to heat tap water and the radiators, and the pressure is within the normal limits (just over 1 something).

Any ideas at all, please? I would be really grateful for any thoughts at all on what it might be.

 

[ChrisR]

Can't remember specifics of your boiler but 10:1 there's a device (diverter valve) which detects water flow and diverts boiler water so it can be heated - and that's packed up. Usually has a rubber diaphragm in it which perforates.

 

[rhodes]

Thank you! That was a quick! Unfair question coming up: is that likely to be a madly expensive thing to get fixed, if it is hat you think it might be?

 

[rhodes]

I have just remembered that, some time in the summer, the radiators came on for no apparent reason. It might be irrelevant, but could that be related to the same thing?

 

[ChrisR]

Depends exactly how the "diverting" works - don't have details to hand. But eg if the boiler comes on to heat water and the diverting isn't complete thwn you would get warm rads.
Hard to say £ - could be just a rubber diaphragm or whole valve, which itself could be over £100 though HRPC spares site shows one for a C&M combi 80 as £32.

You prob will find your hw works a bit if the boiler is on for heating .

 

[rhodes]

Many thanks again. The rads seem to be heating up more than ever, and the water is stone cold. It is sometimes slightly warm to begin with, but my guess is that the pipes carrying the water to the taps are close to a radiator or a pipe leading to a radiator, and the water is being heated in that way.

According to the maintenance and service guide that came with the boiler, it mentions a three way valve, which is probably the diverter you refer to. I do hope that it is nothing too expensive - we could do without that at the moment!

 

[rhodes]

In case anyone is interested, the bit we need, apparently, is a motor that helps the three way valve to do its thing. We should have hot water again by Wednesday, with any luck. No news yet on the price though...

 

[supersparks]

get one and fit yourself....couldent be simpiler andd i think they are universal(ill soon be corrected...)
screwfix sell em for about £30 i think....
its just a screw and 2 wires....

 

[rhodes]

I don't think I would feel confident enough to do that, and my wife would probably be even less confident about me doing it! The plumber is trustworthy enough, anyway, I think, but if he charges too much more than £30 for the motor, I might begin to ask questions. Also, he spent a bit of time diagnosing the fault, so it sems a bit cheeky to get free advice and then trot off and get the bit and fit it myself.

 

[ChrisR]

I doubt it's the common type motor (about £15 in Wickes) and fixing - I've seen several different ones.

Motors generally stop working suddenly and completely. Anything gradual or intermittent os likely to be the mechanics of the valve - change the whole thing.

 

[rhodes]

I doubt it's the common type motor (about £15 in Wickes) and fixing - I've seen several different ones.

Motors generally stop working suddenly and completely. Anything gradual or intermittent os likely to be the mechanics of the valve - change the whole thing.

Oh dear. I think that's what he is going to get. I wasn't around when he popped round earlier. Oh well, we shall see...

 

[ChrisR]

You might be lucky - he has seen the thing. If it's different he can put it into stock - I've got about 20...

 

[rhodes]

I guess he has nothing to lose if the motor is universal. I shall let you people know how we get on. Meanwhile, thanks again.

 

[rhodes]

The plumber came today. He replaced the whole three way valve unit, including the motor, and we have lashings of hot water again.

Thanks, Chris R.