Condensing Boiler water drips from flue

matthead

Hi, I have a Ideal Isar Combi condensing boiler, have noticed that the flue drips water when the boiler has been in use for some time.

Is ths normal, if not what could be ausing the problem

Regards

The_Biff

We had a dreadful Ideal Minimiser condensing boiler that only lasted 8 years. It used to drip all the time and it was sited upstairs but directly above the front door. We & visitors would get dripped on! I would complain about this each yeat to the BG serviceman & one year the guy listened to me, came back with his ladder, tightened a small screw in the exhaust pipe & then placed a small bead of silicon sealant on the exhaust thing to stop the water. I believe the drip then ran backwards & was vapourised. This cured the problem.

RedOnRed

matthead wrote:

Is ths normal, if not what could be ausing the problem

I think it must be normal. My new Worcester Bosch does the same and seems to be functioning normally.

You have to appreciate that a hell of a lot of steam comes out of the flue, so a few moisture drips are inevitable really.

alanobrien

matthead wrote:

Hi, I have a Ideal Isar Combi condensing boiler, have noticed that the flue drips water when the boiler has been in use for some time.

Is ths normal, if not what could be ausing the problem

Regards

This happens as a result of the differential temperature between the boiler exhaust and the outside world. Most of those i have seen drip to some minor extent.

Assuming its not a constant flow of fluid, i would not be to concerned.

aliasojo

Isn't this more to do with the angle your flue runs at? It should be at a slight incline, as The Biff says previously, the condensate should run backwards down the flue and then be discharged elsewhere.

My condensate discharges into a nearby outside drain. No drips at all from flue.

Doglover88

the discharge from some condensing combi's, especially at night and when cold can be loads, Fire Brigade have even been called out to suspected fires and it turns out to be a boiler

the_gasman_2

aliasojo wrote:

Isn't this more to do with the angle your flue runs at? It should be at a slight incline, as The Biff says previously, the condensate should run backwards down the flue and then be discharged elsewhere.

My condensate discharges into a nearby outside drain. No drips at all from flue.

The flue should have a slight incline back to the boiler of usually around 3% of the flues length. The steam vapour you mention is what we call "PLUMING" and is due to the flue gas temperature being close to dew point.(approx 56 degree's)
If your boiler is pluming it's running efficiently. So thats good news cause its saving you pennies :beer: