Combi Boiler - no hot water/water gushing noise in boiler

[immcinto]

Hi, I have had a Ferroli 35C condensing combi boiler for 18 months with no probs. Last night boiler started making water gushing noise and when I tried to get HW from the tap nothing came out. I turned off the cold water mains into the boiler and noise went away. CH is working OK.
Also, I think I noticed that the cold water pipe into boiler was really cold (condensation etc.) , it was like this all the way back to the mains water tap into the house. When I turned off the supply to the boiler the mains pipe seemed to return to normal temp (this may have been my imagination)!
Also the gushing noise and cooling effect is observed even when Ferroli is turned off.

anyone know whats up?
cheers for any help
.jim.

 

[chrishutt]

Sounds as if you are losing water from the cold main through the boiler. Could it be that the PRV is releasing water?

The PRV should discharge via a copper pipe to outside, but it seems quite a common installation fault for this to discharge via the condensate drain, so worth checking that too.

What is the pressure shown on the gauge? Does this vary or remain steady? Also what does the boiler installer (was he Corgi registered?) say about the problem?

 

[immcinto]

Thanks for the reply. There is no water coming out of the PRV. The CH pressure is remaining constant. The boiler is definitely cooling the water in the cold water mains pipe...