Baxi 100/2 HE Plus tripping out

[Slaydeuk]

My boiler is tripping out on over-temperature and it is the fan temperature cutout that is doing it. I have replaced the fan overheat thermostat, which has no effect.
When I remove the fan compartment cover, the fan casing is very hot to the touch and I can understand why it is cutting out. If I leave the fan compartment cover off, the boiler runs OK and the fan casing is cool to the touch. The fan is running.
Can anyone suggest what is causing the fan to over-heat? Following the Servicing Manual fault finding instructions, I end up replacing the PCB, which I am reluctant to do unless there is good reason to believe it is causing the problem. I can't see how the PCB could be causing the fan overheating but I would appreciate any comment or advice on the problem.

 

[baxpoti]

Was there a lot of white or red dust in the compartment?
If so the comb box door seal has perished and will need replacing by a competent person.

 

[Slaydeuk]

There is some dust in the bottom of the fan compartment, but only as much as I would have expected. We have only been in this house just over a year and I understand that the boiler had only recently been installed when we bought the house. Would you suggest I remove the combustion chamber cover to inspect the seal?

 

[Slaydeuk]

I jumped the gun and removed the combustion chamber cover to examine the seal. One side seemed to be brittle and a piece had broken off in removing the cover. I then replaced the seal with a new correct part and the boiler worked OK for a while and then tripped on overheat as before.

The fan casing was too hot to touch, so I can see why it is tripping, but where is the heat coming from? When I run it with the fan compartment cover off it runs quite cool.

 

[RandyMarsh]

Did you ever find a solution for this problem?

I have a customer who's having the same problem and I've also replaced the seal...to no avail...

 

[bengasman]

Hey, the cowboy is back.
You shouldn't meddle with boilers if you are not a RGI.

 

[RandyMarsh]

How would know if I was a RGI or not?

No one can know everything there is to know about every boiler out there! Thats the point of this forum isn't it? If a RGI comes across something unusual in the field they can post a question on here?

I wasnt even asking you anyway, why you getting involved?

Get a life!

 

[bengasman]

Just about every RGI on this forum is present in the cc, you are not; not conclusive evidence, but a good pointer.
I recognised you from another post where you asked a question that did not sound as if it came from a RGI; not conclusive evidence, but a good pointer.
Made me curious so I looked at your profile, doesn't say you are a RGI; not conclusive evidence, but a good pointer.
So I looked at your posts, ahum; not conclusive evidence, but a good pointer.

Conclusion: you are either a chancing cowboy, or you are the worst RGI that has come out of plumbers' shcool in the past 5 years.
My money is on the cowboy.
And I don't like cowboys; they give my trade a bad name.