Baxi combi 105e problem

[valhalla728]

Recently we have had some very heavy rain here and unfortunately our guttering failed and water has gushed onto the flue basket. Next day the heating and hot water were playing up. Now checked inside and thought it might just be a sensor as this has gone several times. Replaced that and still nothing...anyway, loosened screws for the boiler backplate and yes you guessed it, loads of water came pouring out onto PCB....sooo, replaced PCB this morning, dried everything out, replaced C/H sensor and fired it up....Fantastic, water got lovely and hot AND the heating had never been so hot....in fact un-nervingly hot...Could not even touch the radiators...so switched off...Have returned later in the day to switch on again and does not want to know now...It goes through all the cycles off starting, i.e neons,pump, fan and then ignites but drops flames immeidiately...This happens only on the C/H...Hot water is fine and remains ignited...
Any advice will be gratefully recieved

 

[holty]

a reason why just anyone shouldt play with boilers.even though youve not tuched the gas, your still replacing somthing fundamental to the workings of gas components.basically you cant just throw a pcb in without the knowledge of setting up its operations, eg checking pots and gas pressures.

 

[powell30]

Seen this loads of times......water ingress down flue, fan gone, water in gas valve and or sensing tube.....time for an RGI.

DON'T mess with it anymore.......

 

[mickyg]

powell, would it not affect the hw as well?

btw, agree it needs checking by an rgi, just interested in fault condition.

 

[valhalla728]

The problem is that it was actually working with the water in it albeit roughly.I t was only the fact that I had got water onto the PCB that I had changed it. Also, its funny how it was working ealier in the day and then this sarvo...no heating. Have had a word with a matey and he seemed to reckon that it might be the flame sensor electrode for that would have been submerged in water and he said that the heating burner flame starts lower than the HW and is not picking it up...

 

[holty]

think you need to get an rgi in who knows what hes on about.your matey is well off the mark.with the flame rec.

 

[baxpoti]

would it not affect the hw as well?

C/H starts on low gas setting

 

[valhalla728]

For those that might of been interested it turns out that the problem was
1-PCB
2-Gas valve...had water ingress and was making the burner fluctuate...There is a breather pipe from the valve which connects into the burner chamber which filled with water....there you go

 

[baxpoti]

water in gas valve and or sensing tube....

 

[valhalla728]

well it just goes to show that some people do know what they are talking about...