Ravenheat combi condensing boiler Ignition cycle failure

I have a Ravenheat CSI 85 A (T) combi condensing boiler which is approx 14 months old.

Until today it has been working fine when a fault appeared on the CH side

The fault only affected the CH aspect and the DHW is working completely normally.-

Normal ignition cycle. Fan Full speed, gas requested, ignition high flame for approx 5-10 secs before dropping in to lower flame for approx 30 – 45 secs and then rising again to required level.

Two conditions exist: Fault condition is Ignition cycle fails mid cycle and goes in to repeating attempt to light the boiler:

When the boiler is at low temp the cycle is longer and lasts to the point where the flame has reduced ready to rise but at this point instead of rising it go out and the cycle begins again.

As the boiler is warm the cycle begins to repeat at an earlier stage. – after ignition it goes out immediately.

Finally if during the ignition cycle the hot water is requested for approx 30 secs or more the ignition is completed the boiler runs normally whilst dispensing the hot water and interestingly when the DHW is switched off by the closing of the hot tap the boiler continues to support the central heating until it no longer requests heat.

My instincts are suggesting CH Themister any thoughts??

KJ

Contact Ravenheat as they provide 3 year parts and labour warranty if fitted correctly and serviced each year.

Pete

Fan Mod PCB

Thanks Pete. will check out guarantee,

SortedPlumbing, would fan module be issue if DHW is working correctly? as in both DHW and CH the fan has to run full speed before ignition, could you please explain further

thanks KevinJP

Yes it would. In this case the fault will show worse just after the HW has been used.

Fluffster said:

Contact Ravenheat as they provide 3 year parts and labour warranty if fitted correctly and serviced each year.

Pete

Click to expand...

Ravenheat are quite strict that their boilers should only be fitted by CORGI engineers who complete the Benchmark Certificate.

If thats not evidenced then they often will not operate the warrantee after the first year.

Tony

Basic Fan Mod fault - doesnt affect H/W as hot water requires the boiler to work at full flame.

The fan mod fault only shows up when the boiler wants to modulate to low flame. The actual fault in the pcb is the board is unable to modulate and just switches off, hence why you get on, off , on, off etc.

Other fault i have found with the fan mod pcb is 'failure to light' (soild red light) and this was caused as power from fan mod PCB to fan was only 120Vs and it should be 240V.

Had this a few time now.

Guys

Just wanted to say thanks for the feed back, I desided to get the experts in and you where right when you identified the fan modulation board.

The DHW can continue to function in a normal manner whilst the CH fails to ignite correctly. The Gas guy who looked at the boiler was himself a little surprised that if the DHW was used at the same time the CH was calling for heat that the CH would stay with flame once the hot tap had been closed until such time as the CH reached temperature

thanks again
Kevinjp