I have a Vaillaint G3 - Combi Boiler. It was working fine till yesterday, when I noticed the hot water turn cold despite the boiler firing consistantly. ( central heating turned off for investigation purposes as it is working fine)
The same is happening on all the taps in the kitcken,and baths.
I checked the pressure (1.2) OK, still firing ,OK, checked the HOT water outlet - very hot during start but it gradually turns cold. A click sound is also heard within the boiler.
If i turn the (cold) hot water off, and re open the whole process restarts. Very hot -warm then click and cold again.
Can anyone suggest what i can do. I am a maintenance Engineer and should be able to rectify minor problems. If not i have to call a plumber !
The same is happening on all the taps in the kitcken,and baths.
I checked the pressure (1.2) OK, still firing ,OK, checked the HOT water outlet - very hot during start but it gradually turns cold. A click sound is also heard within the boiler.
If i turn the (cold) hot water off, and re open the whole process restarts. Very hot -warm then click and cold again.
Can anyone suggest what i can do. I am a maintenance Engineer and should be able to rectify minor problems. If not i have to call a plumber !