Boiler flue rain shield

[Moneypit42]

Today our boiler kept tripping the RCD but with no fault code showing, and the engineer found the fault to be moisture around the area of the pcb. Once dry everything was fine. I've never seen this fault and he suggested it could have been rain ingress into the flue as last night was very wet & windy. A hairdryer sorted it! Does such a thing as a proper suitable flue cowl exist to prevent this happening again? If so could I fit it myself? Am experienced diyer.

 

[CBW]

Usually just an aluminium heat resistant sheet above I think. No such cowel I know of exists. I’ve only had one go like that, and I think it was from a blocked gutter and torrential rain.

 

[Madrab]

Depends how the rain is getting in, is it a vertical flue or out the wall? If it's out the wall then and that wall is exposed to the wind and the rain then the water may be getting driven horizontally into the flue.

Did the engineer not suggest anything? May need to look at some type of moisture barrier to stop it getting to the PCB internally.

 

[Moneypit42]

Thanks all, sorry for slow reply, net v busy just now! Flue is coming horizontally through a vertical wall. I thought maybe a curved steel cowl as for extractor fans would stop falling & wind driven rain. Never had this before in our 10yrs in the house!

 

[MeldrewsMate]

...Never had this before in our 10yrs in the house!

Perhaps you have answered your own question. Fitting a cowl around the flue may create unexpected consequences, and if it's unlikely to repeat during the life of this boiler then perhaps it's best not to run the risk. Is there protection you can give to the pcb instead?
As you haven't given the make and model of boiler then it's much harder to give relevant advice.

MM

 

[Moneypit42]

Boiler is Glow Worm 15hxi in kitchen. Flue is on external east facing wall. The rain usually comes in from the SW.