dripping flue

[ambrosia]

attended a flat where the customer had reported a leak, turned out to be the flue which had quite a long run with 2 elbows and a coupling on it, all internal with no boxing. (pretty ugly)
the flue was level rather than tilted back to the boiler and had sagged slightly. The water was sitting in the flue and was slowly dripping out.

My reasoning was if its dripping water it cant be air tight, so switched it off and told landlord to call the installer to come put it right.

However the installer rang me up ranting about how out of order i was etc, that i'm making a mountain out of a mole hill etc

i dont really careabout the installer, thought he's an idiot before this. But i was wondering how most people would classify this situation, to me a flue that is leaking in an internal room is an ID

(also I need to talk to vaillant to see what the max length of a flue on an eco tec plus 24 is)

 

[mountainman]

Well done mate, the installer is totally at fault.
Got to be made safe as flue is not correct.

 

[ambrosia]

thanks Mountainman,
but would you classify it as ID, had there been no leak because the sag was slight i might have overlooked it on a cp12.

 

[Millsy 82]

I would have classed it as ID. The chances are that a joint has been pinched as I had this problem a few months ago and we sorted out the fall back to the boiler but it carried on leaking changed the seals and it was fine.

The overall length of the flue is quite a distance (Around 12 meters I think for the 24 but I would double check that)

 

[mountainman]

I'd say AR as IMO, ID would pose an immediate risk to the occupants, I don't believe a condensation drip from a flue seal could be classified as such.

However, if you download the MI's for the boiler you will probably find that the installer made a poor job of the flue which COULD have resulted in an ID.

All said though, there should be a continuous fall back of the flue into the boiler, each joint should be secured by a screw secured clamp and appropriately supported.

 

[kozak1968]

Dripping flue would indicate a break in the exhaust / inner flue. Condense would run down exhaust and usually back to boiler and trap. If it only happened when it rained it could be the outer flue damaged. Put the analysiser probe in the intake of the flue turret to see if the co reading goes up and this would indicate a corroded or damaged inner flue. I would

 

[HeatStar]

Agree with above. If found to be a brake in exhaust inner tube after FGA then it's ID.

By the way the max horizontal flue length on an Ecotec plus 824 is 8m with one elbow on the standard 100mm pipe. Seeing as the system in question has 2 elbows then your max allowance should be no more than 7m as each additional elbow after the one allowed subtracts 1m from the max length.

 

[Sniks]

Hi.. have fitted loads of vaillant boilers over the last few years and I have noticed recently, on any flue length over standard rear or side 600 to 800mm long that some of the joints are leaking.. I have also noticed on inspection that the flue seal rubber has disintegrated allowing water to drip into the outer flue and then out of the external joint. It doesnt appear to have any bearing that the flue was screwed together externally, and surely if it is supported correctly it shouldn't leak as a seal should be a seal regardless of orientation !!
i am going to take this up with vaillant as it may be a problem with the recent manufacture of rubber seals.

 

[AWheating]

keep us informed on there responce.

 

[Nostrum]

Had a load of vaillants of all ages suffering from this. I always A.R once I've analysed the air intake which never shows up any issues. Poor seals I think that don't last the life of the boiler. Probably partly caused by rough cut flue lengths jammed together with no lube. Seen quote a few with corrosion damage to outer metal as well.