3yr old Ravenheat Combi Boiler!

[titchyboybach]

My bro has a Ravenheat boiler which takes a few minutes to fire wether it be on ch or hw mode? When turned on it goes through all the motions of lighting i.e fan running etc but just doesn't light? it'll do this a few times then eventually it will fire (sometimes taking up to 5 mins to light). Once it has fired it's ok and will stay lit. I was told this may be the thermister but if this was the case wouldn't it be either ch OR hw rather than both? Is it more likely to be the pilot burner? any help appreciated! Thanks, Kristian. [/i]

 

[idealnumber1]

air pressure switch

 

[bobw1956]

Is the Pilot lighting, and then failing to go to main burner?

 

[titchyboybach]

Is the Pilot lighting, and then failing to go to main burner?

Not sure? i don't think so, but i'll have to check! i don't think it's the air preasure switch?

 

[bobw1956]

Why not the aps?

 

[bengasman]

Odd that it doesn't lock out. Don't know this boiler by heart, but if there is no flame at all, it should stop attempting to fire after about half a minute or so.
Apart from that my first guess would be aps, second would be dodgy pcb (based on the not locking out combined with the slow firing)

 

[Agile]

Odd that it doesn't lock out. Don't know this boiler by heart, but if there is no flame at all, it should stop attempting to fire after about half a minute or so.

Thats not surprising as he has not told us which Ravenheat model it is!

Accessing the APS means opening the combustion chamber. It also means its not a premix boiler.

Tony

 

[titchyboybach]

if it was the aps would the fan not run?

 

[bengasman]

... When turned on it goes through all the motions of lighting i.e fan running ...

Maybe a clearer description of what happens is needed

 

[Agile]

if it was the aps would the fan not run?

I know its very simple logic but think to yourself that the purpose of the APS is to CHECK that the fan is running!

So the fan has to run FIRST so that its operation can be checked.

Tony

 

[bengasman]

Do I have a problem with my reading? The way it is stated in the first post gives me the impression that the fan IS running.

 

[titchyboybach]

Yes the fan is running! i'm pretty sure that it goes as far as the stage of lighting without lighting (don't think the pilot lights) then it keeps reseting itself until it actually lights sometimes taking up to 5mins. Once lit there is no problem with it cutting out because as soon as it lights it'll stay lit until turned off/when theres no longer demand?

 

[Agile]

He clearly said the fan IS running.

Thats confirmed too when he later says it eventually lights up ( which would need the fan to be running! ).

Tony

 

[bengasman]

Does the fan run continuously during that period, or does it stop and start?

 

[titchyboybach]

continuosly i think?