# Gas Boiler-Excessive Drip from Condensate Pipe



## MG01 (4 Jan 2011)

Hi - noticed that our condensate pipe from the Vokera Mynute gas boiler is dripping excessively outside and by excessively I mean fillinging a small bucket of water across a 24hr period.

The boiler appears to be firing ok, albeit there is a sound of gushing water when the boiler is turned on (more so than normal) and also the water pressure gague is reading zero.

The boiler is located on the top floor of the house, cold water tank in the attic, condensate pipe pokes out the wall of the house just below the boiler and drips down onto the roof of the kitchen extension below (i.e. - it's at first floor level).

any help or ideas appreciated!
Thanks - MG


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## johnnygman (4 Jan 2011)

I would imagine that this is quite normal assuming it is a condensing Boiler, My own would produce a similiar amount of water/steam which will drip off.
If the water pressure is low this can be topped up from the valve below the boiler to the correct normal level, that should be indicated on the pressure gauge.


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## Shane007 (4 Jan 2011)

MG01 said:


> The boiler appears to be firing ok, albeit there is a sound of gushing water when the boiler is turned on (more so than normal) and also the water pressure gague is reading zero.
> Thanks - MG


 
If pressure is at zero, it is highly likely that you have a leak in your heating system. System pressure when cold should be approx 1 bar and will rise to approx 2 bar when hot. Other causes could be faulty pressure relief valve, faulty pressure guage, or defective expansion vessel. More likely to be a leak though with the sound of gushing water. If water from the system has leaked out, it will be replaced with air and when the pump starts up, you will hear the gush.

Would recommend that you have the system inspected by a qualified heating engineer/plumber asap.

With regard to the condensate, the amount will depend on how much the boiler is on in that 24 hour period. There will be a continuous trickle when the boiler is on and in condensing mode. Just make sure that the condensate pipe outside is well insulated, as this will freeze in the weather that we have been having and thus lead to possible boiler shut down. Insulate with exterior grade insulate of least equal diameter of the pipe it is fitted to, so if pipe is 22mm diameter, then insulate with same. Overall cross-section will be 22mm insulation + 22mm pipe + 22mm insulation. Don't leave out bends, etc.


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## MG01 (5 Jan 2011)

Thanks for the responses. I'm going to try and top up the pressure in the system this evening and then I'll monitor it over the coming few days to see if I loose pressure at all (confirming the leak). I have a qualified servicer due out next week to take a more indepth look at it.
Any more advice let me know - greatly appreciated
M


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## MG01 (11 Jan 2011)

Right - saga continues.
Never succeeded in topping up the pressure. Had a guy come out to service / look at the boiler there yesterday. He pointed out that the boiler is not a condensate boiler and the drip was infact the pressure release valve. He corrected that, said everything else looked ok and went to fire it up again - wouldn't fire. Pressure at zero. He figured that the boiler is mounted at the top of the house, just below the water tank in the attic and reckoned there wasn't enough head of pressure to get it going. He by-passed the pressure sensor and got it firing but reckoned that the system wouldn't work later on that day when we came home from work.
Came home from work and the boiler had come on and was behaving itself - leak is fixed (coz he reset the prv) but the guage still reads zero. It fired again this morning on timer - again with a pressure reading of zero.

So - basically it all seems to be working - but the pressure reads zero...any ideas? The best he could offer was that the system could be switched to mains fed from tank fed?
Any thoughts?


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## roker (11 Jan 2011)

If the pressure gauge is on the boiler on the top floor it would obviously read less than if it was on the bottom floor where most boilers are mounted, because of less head of pressure.


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## villa 1 (12 Jan 2011)

I can't understand how your gas boiler has been operating in the past with simply very little static pressure if it was indeed fed from an feed and expansion cistern fitted just above it.
I'd go with your service man's recommendation, that is, to fill/charge the boiler/heating system from the mains which should be in the vicinity of the gas boiler.


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## roker (12 Jan 2011)

depends where the gauge is located. 1 bar = 33.5 foot,
 If the gauge is on the ground floor and the boiler is on the upper there will be near zero pressure at the boiler. or visa versa, if the gauge is on the boiler there will be zero pressure on the gauge and 1 bar on the ground floor.


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## DGOBS (12 Jan 2011)

I have only one thought, your serviceman 'bypassed' a safety device, if it was left in this fashion and your system emptied then you in trouble! (so is he)

Yes to sealing the system


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## MG01 (13 Jan 2011)

ok - bit confused.
The cold water tank (presumably the feed tank) is situated in the attic, boiler is located about 15ft. to the left of this and just below (i.e. - mounted on the wall in the landing). The house is a 3 storey house with kitchen on the bottom floor. Rising main feeds the attic tank and it would be possible to take the feed for the boiler up at the top of the house at the same level as the boiler (this would be easiest I reckon).

The question then is whether the rising main would give 1bar pressure up this high and also - why is my boiler firing if the pressure guage (the one on the boiler itself) is reading zero or close to it??

leave well enough alone or get somebody out to look at it again (and if so - who? BGE?
Thanks


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## villa 1 (13 Jan 2011)

Get some suitably qualified to look at the installation.(plumber/gas serviceman).
Looks like you have just enough static head pressure for the boiler to operate properly, which is surprising.
Get your plumber to check the pressure off the mains in the attic and if it goes above 1/2 bar, 7psi, connect this mains to the boiler. This should satisfy your existing boiler (as it's practically working on a dribble fill at the moment!!).


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## DGOBS (13 Jan 2011)

Mynute water pressure switches can be adjusted downwards so the can operate on open systems (can be adjusted to work at practically zero pressure)


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## MG01 (14 Jan 2011)

Is it safe to turn down the sensitivity on the Mynute to get it to fire with little pressure?


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## DGOBS (14 Jan 2011)

to a point, it's not safe to go to the point where it would fire if empty!
the switch should only be adjust by a qualified person


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