Water coming in flue pipe after boiler installation

[jontris]

Well, it's definitely rain water. This only happens when it's raining. I've also proved it's not coming along the outside of the flue. A cloth tied round the flue as it enters the boiler remains bone dry. It's not coming down the gas side. I've got one of those directional extensions pointing downward. It must be rain water flowing back down the flue on the air side. Properly installed where would this water go?

 

[Billy Bob Bob]

Well, it's definitely rain water. This only happens when it's raining. I've also proved it's not coming along the outside of the flue. A cloth tied round the flue as it enters the boiler remains bone dry. It's not coming down the gas side. I've got one of those directional extensions pointing downward. It must be rain water flowing back down the flue on the air side. Properly installed where would this water go?

the water would go to the heat exchanger then down the condensate pipe what potterton is it?

 

[jontris]

OK, so is it the same whether it's the gas side or the air side? Potterton seem to think that water on the air side would just come out the bottom.

I presume they think they've designed the flue so that water couldn't get in but I've tried pouring water on top of it and seen that it can curl inside the vents and drop inside.

It's a Performa 24 HE btw.

 

[Billy Bob Bob]

right then,i have installed 156 performas unless the flue elbow seal is damaged or mis aligned there is no way water can come back in,the flue is a good design and i have never had this problem,back to your installer,somethings a miss

 

[jontris]

I'm really grateful for the interest you're taking.

Are you saying that rain water can't come back along the inside of the flue and back into the boiler? Or are you saying that it can come back but it wouldn't drip out of the bottom. Either way you seem to be saying that Potterton have got it wrong about their own boiler.

BTW I have had my installer back and he insisted that the water must be coming along the outside of the flue. I knew it wasn't and I've since proved it.

 

[tamz]

Every condensing boiler made by every manu has the flue fitted at an angle of approx 5 degrees sloping back to the boiler so that the condensate in the flue gas (from the inner pipe) falls back to the boiler and then to drain.
This means that the air intake (outer pipe also slopes to the boiler therefore any driven rain will enter the air intake which leads to the inside of the boiler.
ALL the manu's know this could happen but they are stuck between a rock as the condensate (acidic) must run back to drain.
BTW non condensing FF boiler flues sloped away from the boiler to stop this happening and on older balanced flues, it just happened anyway although nobody noticed for a good few years until it started rotting.

 

[stevetheplumber]

i can see this being a major problem in future as rain water entering through the air inlet has nowhere to run to probably going to need redesign to allow water to enter the condensate pipe work via some kind of seal
in theory this water could be drawn into the fan

 

[jontris]

Thanks again respondents.

So ... the answer is that rain water CAN get back into the boiler. On the gas side it goes back into the condenser and isn't a problem. On the air side it has nowhere to go but down. My installer laughed at me when I suggested this might be happening.

My flue is high up and exposed, so I may be more prone to the problem than most. I suppose one solution would be to build a cover to protect it from the rain.

 

[rob jefkins]

Just had to replace a fan on potterton 70HE because rain water had come in through the flue and blew the fan motor. Obviously a common fault here.

 

[sparky]

A stab in dark but could the inner flue pipe have been cut accidently when cutting flue down? Have seen this before with water coming into boiler.Havent read all posts so apolagise if this has already been mentioned.

 

[Unregistered]

switch boiler off,get gassafe engineer to have a look.your discrpition of fault is to vague,why do you need de humidifyer.the flues are designed to fall back to allow condesate water produced, to run throu boiler and out vai con pipe

this is the boiler i have and i am having the same problem

 

[Dotty]

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