Rainwater ingress to boiler in heavy rain and wind.

[Paul Cumbria]

My partner has a Worcester Bosch condensing boiler, and during bad weather spells with the wind in the wrong direction, rain is being blown in through the air intake (balanced flue). The boiler itself is beginning to suffer with corrosion, and we worry about it affecting the internal electrics; the units under the boiler are also suffering damage.
Can anybody recommend some kind of cowl to fit over the whole of the external flue which will stop this happening without restricting airflow or exhausting? Anything we have seen online seem pretty flimsy, and look as if they will prevent ingress from above, but not horizontal driven rain - on the Cumbrian coast this is not unknown!

 

[Dekzion]

your outlet is two pipes one inside the other. the central one is the exhaust. I would measure it and find a piece of tube that is a sliding fit and allows you to extend it by maybe 100mm, if it slides inside by a 100mm or so so much the better as that'll keep it straight.
Then get yourself a piece of thin, fine stainless mesh. (250mm x 250mm?) The smaller the mesh the better.
Here comes the arty bit, form the mesh into a tube with a closed end much like a cup that will just fit inside the outer tube, cut a cross in the closed end so by pushing it on the inner tube the cross opens and slide the mesh on and into the outer tube. The cross on the tube should grip it okay and the mesh will act like a miners lamp stopping rain
Thin mesh is easy to cut with some heavy-ish scissors.

 

[Paul Cumbria]

your outlet is two pipes one inside the other. the central one is the exhaust. I would measure it and find a piece of tube that is a sliding fit and allows you to extend it by maybe 100mm, if it slides inside by a 100mm or so so much the better as that'll keep it straight.
Then get yourself a piece of thin, fine stainless mesh. (250mm x 250mm?) The smaller the mesh the better.
Here comes the arty bit, form the mesh into a tube with a closed end much like a cup that will just fit inside the outer tube, cut a cross in the closed end so by pushing it on the inner tube the cross opens and slide the mesh on and into the outer tube. The cross on the tube should grip it okay and the mesh will act like a miners lamp stopping rain
Thin mesh is easy to cut with some heavy-ish scissors.

Thanks for the advice. I guess the inner tube would need to be stainless as well to resist corrosion from the exhaust gases. I will have a look around my local hardware store. Cutting won't be a problem as I have tin shears.