Our boiler (Feroli Optimax 25OV) stopped working this evening with a flashing fault code - I traced the fault to a blocked condensate drain, (presumably frozen), so I've restored functionality by temporarily running the condensate into a bucket. (hero points from SWMBO hopefully !) The boiler is in the loft, and my question is can I safely leave the bucket overnight, or am I likely to have a very damp ceiling if I persue this route? Just how much condensate do you get from a boiler per day? Help please or my hero points may be rapidly removed! Thanks, Mike
A bit of heat to clear the drain and it will run for a while. The drain should be replaced with 32mm pipe, and that will fix the problem long term. You want to make sure there are no sumps in the pipe too - so it can drain empty, no u-bend type things to freeze solid.
See thread
Cold weather condensing boiler breakdowns x 2 Frozen condensate pipes
HTH
Andy (who is glad to have old, inefficient, non-condensing boiler!)
I thought our plumber (who ran the condensate pipe into the soil pipe behing the upstairs toilet - boiler was in the loft) was a bit of a bodger. However I'm beginning to see the advantages!
Hmm? In the loft; off for sufficient time for the bucket of water to gain dripping condensation on the outside ending up where? Needs a "driptray" to surround it methinks.
I am running a temporary *lash up* 26kW combi to bring some flooring up to running temperature. At present the room stats are holding at 13deg.C and the boiler between 40 and 50deg.C Two decent sized rooms plus a bathroom. 24 hours collects about 2 litres.
Andrew Gabriel wibbled on Monday 21 December 2009 10:47
Wouldn't that be a good use for trace heating tape on the outside, wrapped in some insulation?
My BCO questioned my decision to dump the condensate from my future boiler into an internal trap into a internal drain (but he wasn't 100% sure - he just thought it was usual to dump into a gulley). Having seen internal drains mentioned in the installers manual, I'm of a mind it's a far better idea if available.
Do some boilers absolutely require an external discharge, say to do with fumes escaping from the condensate drain?
Having it inside seems more sensible to me. Could be powered only when boiler is firing, and only when air intake is below 1 or 2C, if the boiler provided the drive for it. (That's pretty much what I did with the dehumidifier drain.)
Mine has a U-trap internal to the boiler to prevent fumes leaking out of the condensate pipe, with clear warnings to make sure it's been manually filled before trying to light the boiler for the first time. That U-trap also contains the sensor to detect if the condensate is backing up the pipework, and it generates a specific lock-out code for that (not happened to me yet).
Andrew Gabriel wibbled on Monday 21 December 2009 14:20
I was just thinking about off the shelf products (as ordinary trace tape isn't usually rated to run wet). Otherwise I agree.
I'm wondering about a length of plastic coated greenhouse heating cable, single end fed, trimmed and reterminated to suit 12V and run it off either a transformer or a SELV lighting pack for readiness and simplicity? The greenhouse stuff is of course thoroughly waterproof and SELVs teh backup plan.
Yes - the Viessmann I'm looking into has a U trap and the same warnings.
Yes, I made mine - resistance wire threaded down PTFE sleeve.
I'm not familiar with that. There's heating tape wire which is used on things like external fire sprinkler pipework, which would otherwise freeze no matter how much insulation, as there no flow. Looks a bit like T&E, but it comes in ready made up lengths.
I'm just starting to use a Viessmann Vitodens 100W, 26kW combi.
Mainly because I could buy it cheaper from my builders merchant than the plumber who claims to be trained by them:-) Stainless steel seems a good idea as well.
Do you have anything to note on the install? Gotchas etc. Also, did it appear to be set up correctly from the factory or did it need some adjustment with a gas analyser?
The things should be installed properly with 32mm external drains as per the instructions. I guess it's "trained" Gas Safe/CORGI installers thinking they know better. Why put in 32mm, it's only carrying a dribble of water. Don't need to carry 32mm pipe and adapters...
Mind you I've had a bath waste freeze up solid when there was a slowly dripping tap. Mind that was one of the winters in the early
80's when it was properly cold (daytime maxes below zero for a week in Bristol). Not the current little snap.
Also using electric to heat the drain isn't very green as you have a good source of waste heat available...
Its what I have always done. Seemed preferable to making extra holes etc if there is a perfectly serviceable drain right next to the boiler as is often the case.
The install instructions permit both usually - however that may depend on the boiler.
Not really. The flue has to be specified and ordered. I handed the box over to the plumbers and left them to get on with things. When I came back they were test running hot water down the drain. I haven't bothered with weather compensation although it could be important with under floor heat. Easy retrofit and not requiring a plumber recall.
The gas safety record shows an initial combustion analyser reading of
8.9 (no units mentioned) and a final combustion reading of 8.9 so probably no adjustment necessary. I see the commissioning checklist records CO2 as 8.9 so must be that.
There is a drilling template supplied but they had obviously cocked up the measurements as I now have a spare set of fixing holes. They probably assumed a 12" cavity wall except this one has feather edge cladding.
They filled and pressurised the under floor system but could not test as I had not wired in the thermostats or control valves.
You get two extra years warranty if the installer is Viessmann trained.
Quieter than our Potterton 100E but not silent. The bypass is internal, U bend in condensate pipe.
For the benefit of the archive, there was about 5cm in the bottom of a 'standard' bucket in the morning. Not much more by the following evening!
Why would it have condensation on the outside? - the bucket and its contents are already at room (loft) temperature? Anyway, whatever the theory there didn't seem to be any condensate on the condensate bucket!
I think perhaps the problem I've got is that the condensate is just dripping out at a rate of about 1 drip per second, with no sign of any siphonic action. When I look at the syphon valve it looks like the fluid in the valve is being added to too slowly to start the syphon going. - is that possible?
If the soil pipe runs through the loft then branch into it there. Sometimes it is possible to terminate the condensate pipe into the gutter, depending on circumstances.
A loft is regarded as outside if vented - the roof is just to keep the rain off the house, not insulate it. "ALL" pipe must be lagged in the loft and that includes condensate pipes and copper pressure discharge pipes. A small let by with the PRV may block up the copper discharge pipe.
If it is difficult to get a condensate pipe to outside where it cannot freeze, then use a condensate pump. Or use an Atmos, which get the condensate and spays it into the flue exhaust gasses on the way out of the boiler.
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