Ravenheat combi CCSI 85 Fires up then stops every 2 min

[Civbuild]

hI I have a Ravenheat condensing fanned combi boiler CCSI 85. Last year when the hot water was turned on the boiler fired up for a minute then stopped and fired up again, so the water was coming hot - cold - hot.
I lowered the hot water control a bit and hey presto I haven't had any problems since then until now! Now the heating system is acting up, the pressure is at 1.5 bar. The boiler will fire up for about one minute and shuts off with the fan, the pump still runs, then after about 30 seconds the boiler fires up and so the cycle continues. I moved the heating control and hot water control in the hope of an easy fix with no luck of course. Was hoping someone could tell me if this is an easy fix or will it require a Corgi lad to come in?

 

[gas4you]

Without being in front of it, it sounds as though it could be the fan modulating board. (I think it is this model that has a problem, bit late for the grey matter to remember now )

 

[Civbuild]

Hi Dave,
Kind of sad we are on the computer at this time of night, thanks for your reply

Gordon

 

[Agile]

I think that Dave is remembering correctly, in spite of being off work sick!

There are other things to be checked first though.

Because the fan pcb is a known fault its just possible that the company will post you a new one free. john will shoot me for suggesting that though!

Your best bet might be to get the local Ravenheat service agent to come to do the repair as they have all the spares and know the boiler well. ( Its really a simple unit though )

Tony

 

[Slugbabydotcom]

Post September 2005 if theres two lights on the front it could well be the fan mod board.
Pre sept 2005 and three lights, it could be the fan stiffening up.
Whatever the case it needs someone who has a bit of patience with Ravenheats and I would be starting with checking out the thermistors if it was in front of me.

 

[rustyj]

I had a similar problem with a customers csi 85 in Cardiff the other week,
changed the ch thermistor and all seems ok. I would test its resistance first.
John

 

[SortedPlumbing]

Remember the if its the fan mod -
Boiler only shuts ON/OFF on CH
If it works fine on HW prob not fan mob pcb

 

[Civbuild]

Thanks lads for your input, the hot water is affected also thought it might be the ignition board!

 

[Agile]

Remember the if its the fan mod -
Boiler only shuts ON/OFF on CH
If it works fine on HW prob not fan mob pcb

Thats because the fault is showing when the fan should slow down.

It rarely shows on DHW because the power input is much higher.

I expect it can be prompted by screwing down the DHW flow.

If it happens at higher power outputs its unlikely to be the fan mod PCB fault.

Tony

 

[Civbuild]

Thanks Tony will check that out

Gordon