Ravenheat flame failure

Have installed a Ravenheat LS100T Combi and have a fault which someone may be able to help me with. On first calling for hot water the boiler fires perfectly, but if you then call for water again in the next say 10 minutes the following fault occurs. Pump starts, fan starts, gas valve opens for a second or so (just long enough to blip the manometer) then flame failure light comes on. If boiler is allowed to cool between uses all is OK. It just doesn't seem to want to light when even a little bit warm. Once it is running it will work flat out forever with no overheat lockout.
Do you think there is anything which can be adjusted or shall I call out Ravenheat since boiler is new.
Gas input pressure 21 millibar
Burner pressure 12.5millibar Max - 1.5millibar min (within spec)
Flue length 2.6metres (horizontal)

Thanks

Call Ravenheat. I would be looking for acceptable inlet pressure.

They might want sight of Benchmark logbook.

Thanks DP for prompt reply. What would you call acceptable input pressure. I thought 21mbar was pretty much bang on, or do you mean insuffucient pressure at the burner?

With other gas appliances running, 20 mbar at the boiler with hot tap running.

DP said:

With other gas appliances running, 20 mbar at the boiler with hot tap running.

Click to expand...

I have 21mbar at the boiler input with all appliances on. The other pressures I quoted were outputs from the gas valve to the burner and they are exactly as quoted in the makers manual. I think I will take your advice and call Ravenheat.
Thanks again.

did you manage to find out what was wrong with the boiler?
exactly the same thing happening with mine at the moment.
thanks.

MOD 2

dream on that post is 2 years old

and don't hijack post's start a new thread