BAXI 80 Eco

[Mike212]

I have a 2 year old 80 Eco combi boiler and the following faults have appeared.

With CH on, runs normally until hot water is demanded. Turn a hot tap on and flame goes out & CH and hot water run cold

With boiler set to hot water only, flame lights and water ranging randomly between luke warm and cool is delivered through the taps.

Boiler has had a new PCB and a new diverter valve (fitted by Corgi engineer - not me) - no change. The microswitch on the diverter valve appears to be working OK and the servo that operates the microswitch is workng.

Green light is on, never seen the red light, and amber light comes on whenever the flame is lit.

We are scratching our heads - anyone got any ideas?

 

[micky p]

sounds like it might be overheating. Was the diverter valve replaced because of sludge/scale. It could also be a faulty themistor.

 

[Mike212]

No, it was replaced because the engineer said that it wasn't switching over correctly - there was a pressure increase (shown on the gauge) in the CH system whenever a hot tap was opened.

 

[baxpoti]

You may have a restriction in your primary circuit, check and clean/replace the plate heat exchanger

 

[Agile]

Sounds like a challenge for Chris from this site if you are in the KT area!

Interesting how that CORGI changed two expensive parts although they were not the cause of the problem!

I wonder if they ever looked at the gas valve, setup, sensors or the pump!

Tony

 

[micky p]

No, it was replaced because the engineer said that it wasn't switching over correctly - there was a pressure increase (shown on the gauge) in the CH system whenever a hot tap was opened.

well usually that is caused by a build up of sludge and scale in the diverter valve. If the system is very clean it is quite rare for these valves to go down. Has he checked the expansion vessel. The system pressure shouldn't move that much maybe between 1 and 2 bar max depending on the size of the system.