Main Combi Eco 30 banging

[tomwelch]

Hi all.

First time poster here. I'm a gas safe registered engineer...
Used this forum a few times when on a job to find answers for some problems but can't seem to find the answer I need now.

Just visited a property which has a Main Eco 30 combi fitted in.
About 6 weeks ago I fitted a new heat exchanger.

Anyway got a call this morning the tenant said they had shut the boiler off as it was making load banging noises.
When I got there and checked the boiler on heating and/or hot water mode would start to "bang" and fluctuate between high flame and low flame. High flame obviously causing the noise. The boiler also sounded as if it was "kettling".

Am I looking at a scaled up main heat exchanger?
I've isolated the appliance for now and made safe but obviously the tenant has no heating or hot water so I need to get the problem sorted ASAP.

Thanks in advance.

 

[TCCHeating]

Wrong forum mate. Send your gas safe details to the mods and then post in the combustion chamber. (Normally takes a few hours to process)

 

[gigz]

Is the pump ok ? Sounds like a circulation issue. Is the temp shooting up to 80/90 degrees in a few seconds ? I always turn the gas off and fire it up to stop it boiling if i think its air/pump. Check F&R valves haven't been closed by mistake (custard turning wrong valves off after topping up) or mag filter. Also check return filter in boiler.

 

[tomwelch]

Tcc - will do that now didn't realise.

Gigz - thanks...that was my 1st thought when I got the phone call that it must be pump related. However when I got there the pump was fine and the noise was definitely coming from the heat exchanger continuously with the boiler trying to go high flame.

 

[gigz]

Was the temp shooting up quickly ? Or normal ?

 

[tomwelch]

Normal.

Steady climb.

 

[gigz]

Was the condense pipe/trap clear ?

 

[tomwelch]

Good question.
I'm popping back to the property tomorrow to fix the toilet so I will take a look.

 

[tomwelch]

Would that cause the kettling though ?