Vaillant Ecotec 831 - rainwater ingress

[ingott77]

Hello

We had our 831 installed about 18 months ago never had a problem with it until now. Saturday morning came down stairs to water dripping out the bottom of the boiler. The system pressure was stable at 1.2 bar so I took off the front cover and the inside was awash with water - cleaned this up but couldn't see any leaks - checked around the system and found a puddle of water on the top of the boiler. So called out BG - the BG tech couldn't find any leaks and did not know why there was water on the top either he did find a loose cap on the pump which he done up tight as he thought that might have caused it. It happened again on Monday morning with water dripping out of the boiler had another look inside but again no visible leaks - there had been very heavy rain with strong winds over the weekend so when the BG tech arrived to have another look I mentioned this and he now thinks this could be rainwater coming in through the outside flu and would also explain the water on the top of the boiler.
The outside flu is angled up slightly but the BG tech says this is normal as to stop the acidic condensate from running out of the flu.
Can I chip some of the mortar away from the flu so as to angle it down some to stop the water from getting in or would this stop the correct operation of the boiler? Also does the cap on the pump need to be done up tight as it wasn't before and had never had a issue?
Thanks for any advice
Ingott

 

[ingott77]

anyone ?

 

[RickMoore]

The horizontal flue is supposed to have a slight fall towards the boiler, and angling it down isn't the solution, and without being registered you shouldn't be messing with the flue at all. I doubt this is the problem anyway as it's been fine for 18 months.

You would have to be getting some serious driving rain to get much water into the air intake. Can you post some pictures of the flue ?
I have seen this happen where the inner flue is split and condensate runs back down the intake, did the "bg tech" use a FGA on the intake side of the flue ?

The cap ontop of the pump is probably the auto air vent, which is supposed to be loose so air can escape. They sometimes do leak, but I've never found a leaking one that you couldn't tell it was leaking.

 

[sambotc]

Vaillant flues have the angle built in to the terminal. If it's just the one section it should be pretty much level.

Had a lot of issues like this over the last year or so mainly due to incorrect angle of flue when installed. I'm surprised all the manufacturers don't have the air intake underneath like the old Baxi terminals. At the end of the day if the rain coming in horizontally and hits the terminal it's going to end up in the boiler.

 

[GasBod]

Is it under the guttering?

 

[ingott77]

_

Yes it is under the guttering - the flu was installed through my extension and is about in line with the top of the window. However the guttering is in good repair and not leaking. I did check it when the BG engineer left and had the hose pipe running in it for a couple of mins and all was good....

_

 

[Agile]

I dont remember any excessive winds last weekend.

But gusts and heavy rain can sometimes blow water out of a gutter.

Most flue terminals have a built in slope!

BUT most manufacturers STILL ask you to fit the flue with a slope. When its obvious that no slope is needed one can only expect their staff are unable to engage in any original thought on engineering matters.

You should NOT have removed the front cover of your boiler as that is the gas sealed compartment!

Tony