VOKERA 735, sounds like a train!!

[ROSSGR]

Small problem has developed on my Vokera 735.

Fault on DHW only. After running for 30 seconds it sounds like a train, a repetitive noise. Thinking either non return valve not sitting at plate HX or overheating but it's only 18months old, has a magnaclean fitted and was all flushed out when installed.

It is still modulating, the gas isn't cutting out like an overheating symptom
just an annoying noise.

Any thoughts...cheers

 

[nickso]

kettling? if so its probably ****e in the primary h/e.

first thing to check is the aps tubes and venturi are scrupulously clean, if not it can cause all manner of mayhem including holding the BP artificially high. they will need to be removed to check properly.