NEED HELP for RavenHeat CSI 85 CH problem!

[ukdiyer]

Hi,everyone,i really need someone could help me

i have a RavenHeat CSI 85 boiler and was running fine for few years(Lucky)
but 2 days ago,the central heating stop working at the morning.
i have a room start, when boiler switched on,everything looks fine,
fan was running ok,I saw the flame on, but after few seconds it cut off and back again like a loop.
i found something very interesting is, at that time,if i open the hot tap,keep running for a while,shut it off, the flame keep running,the central heating is coming back!

so at monment,if i need use CH,i have to switched it on,open the hot tap,shut the taps off......

so could anyone give some tips?

PS: i have checked the roomstart is ok. CH bar at 1.5.

 

[Agile]

If you dare to open the PCB cover you could try a couple of things.

There are a few different versions.

If it has a fan mod board at the left then note the position of the CH output power pot on the main board.

Adjust slowly the pot from min to max and see if fan increases speed about halfway.

You can also monitor the fan voltage at the brown wire on the mod PCB. 230v on full power and 175v on low power.

Unfortunately these are rather difficult boilers to work on and neither the MI nor their tech helpline seem to understand how they work. Thats coupled with an inability to properly monitor whats going on inside the boiler. There IS a way but the manufacturers dont seem to know about it or have any details.

I have a problem with one for a customer and whilst its kind of working its not fully resolved yet.

Tony

 

[ukdiyer]

thanks for your help

after changed Fan Control Board,Ch is working now.

 

[Agile]

Could you see anything wrong with it or even post it to me for assessment?

Tony

 

[ukdiyer]

nothing else, just found bad smell one the fan control board.

 

[ukdiyer]

after replaced the fan control board,everthing looks fine until today.
when the boiler switched on and ready to working(time control switched on), I found a question, if sparking make a "PA" noise,
the boiler could not starting fire, but if i heard a continuous "PA PA PA PA",it can be work,anyone could advise me on that?


thanks

 

[Agile]

You could check that the thick ignition wire is properly connected at the right of the main PCB.

Tony

 

[ukdiyer]

You could check that the thick ignition wire is properly connected at the right of the main PCB.

Tony

I have checked both ignition and flame sensor with operly connected at the right of the main PCB.

do you think it is gas valve problem?

thanks

 

[Agile]

Without being at the boiler I cannot say whats wrong.

Unlikely to be the gas valve.

Tony