Trying not to freeze ...!!

[Dave2002]

Has anyone else here experienced the stupidity of British heating over the last day or two. Our condensing boiler is in the garage, but the pipe for condensate/water goes outside and into a drain. The exposed outside part is perhaps two feet at most, and lagged, but still manages to freeze, and eventually the boiler cuts out with an error code as the pipe gets blocked.

I’m not the only one in our neighbourhood who’ve experienced this problem - two others I know have had this today. My solution is not great, but cheap at present. I’ve been using plastic milk bottles with hot water to pour over the pipe, before replacing the lagging etc. Others have a potentially better solution, which is to use a hair dryer or fan heater. I’d go for that too, but I’d need at least a 20metre cable I think, and the longest I have is probably only about 10 metres. I could join a few together but that’s not ideal and potentially dangerous. I will have a 20m cable on order shortly, but I expect it’ll arrive too late to be of use.

Of course if the designers and installers in this country stopped pretending it hardly ever freezes here, so OK to put pipework outside that might be a great improvement!

If anyone from British Gas or similar companies reads this, perhaps they could make this suggestion to their senior management.

[Anastasius]

But how will you get the condensate out to drain away ? Even if you have it running horizontally through the wall, the dribble that comes out will still freeze.

I'm also slightly struggling to understand why there is any condensate (not doubting you for one moment as clearly there is) since condensing boilers only condense (and hence actually reach the claimed 90% plus efficiency figures) when their temperature is less than 55 degrees or so. And most people run their boilers much higher than that. I'm guessing that it's because of the on/off action of a combi boiler (irrespective of fuel type). It has to start from relative cold ...ie below the 55 degrees and so condenses for a little bit before going into non-condensing low-efficiency mode.

Combi boilers are inefficient.

[Dave2002]

I don’t think it’s a combi boiler - but it is a condensing boiler. I believe there is a difference.

The pipe is not quite horizontal. Surely it should be closer to vertical for fast drain off anyway - not horizontal. Most of the pipe run internally must be vertical. Indeed the dribble does freeze, and block the pipe if the temperature is low enough. Wind doesn’t help either. It’s not just peculiar to us - I already mentioned that a couple of other houses within a few miles of us have been similarly affected.

I’m interested in your comments re boiler efficiency - something I should look into. Is there any sensible online literature to explain the modes of operation you mention?

PS: We seem to have survived the night without the heating cutting out, judging by the temperature of the towel rails, but I’ll still need to be “on to this” later in the morning as the temperature is not scheduled to go above zero until tomorrow.

[Anastasius]

I don’t think it’s a combi boiler - but it is a condensing boiler. I believe there is a difference.

The pipe is not quite horizontal. Surely it should be closer to vertical for fast drain off anyway - not horizontal. Most of the pipe run internally must be vertical. Indeed the dribble does freeze, and block the pipe if the temperature is low enough. Wind doesn’t help either. It’s not just peculiar to us - I already mentioned that a couple of other houses within a few miles of us have been similarly affected.

I’m interested in your comments re boiler efficiency - something I should look into. Is there any sensible online literature to explain the modes of operation you mention?

PS: We seem to have survived the night without the heating cutting out, judging by the temperature of the towel rails, but I’ll still need to be “on to this” later in the morning as the temperature is not scheduled to go above zero until tomorrow.

Plenty of information out there. eg https://www.greenmatch.co.uk/blog/20...densing-boiler

Do you have a hot-water tank? If yes then chances are you don't have a combi. If you don't have a tank then you have a combi (unless you have a separate hot water system like a Megaflow.

Oil boilers are also more inefficient than gas as they have a pre and post purge phase which does waste a certain (albeit small) amount of fuel. So nice long burns are the most efficient. When we moved to the current house we inherited a very large and well-insulated thermal store. Ideally it would actually be inside the thermal envelope of the house but it is in the next best location ie my workshop! So any heat losses from it warm up the workshop (which is well insulated in itself). So I have long burns on the boiler to pump heat into the heat store. Then the heating for the house and hot water is taken out of that heat store. When the heat drops by a set amount, the long burn cycle starts again.

In an ideal world I would have underfloor heating (although I loathe it which is why we haven't put it in!) as that would enable the boiler to run in condensing mode all the time.

[Dave2002]

Plenty of information out there. eg https://www.greenmatch.co.uk/blog/20...densing-boiler. If you don't have a tank then you have a combi (unless you have a separate hot water system like a Megaflow.

We do have a MegaFlo. There are problems sometimes - the water pressure from the mains has to be high enough to avoid problems with showers etc.

[oddoneout]

The pipe for my boiler is inside, but convenient as that currently is I'm not sure it offsets the downsides of having drains under the kitchen extension - legally I should add, the constraints of being a mid terrace, and inherited,not my decision.
The boiler is a condensing combi - so the worst of both worlds probably - but again inherited, not old enough to justify replacement and in any case the choices seem to be limited unless starting from scratch or self-build.

[Cockney Sparrow]

We had a new condensing (not combi) boiler installed in late 2016. Would not fire yesterday. Looking at the error code, and the installer's manual, it could relate to several things, including gas pressure. There is a procedure to purge the gas supply (no naked flames around, obviously) and I was thinking of trying that. But this morning when I was about to try it I noticed the condensate drain pipe, which is a push fit over a 1inch plastic drain pipe which goes through the wall and then down to an outside drain.

With a bucket underneath, about a pint of water came out after disconnecting the pipe - and the boiler then fired. So, I will empty the bucket at lunchtime, now collecting condensate and yes deploy a hair drier and then lag the drain pipe! If I had no other means, with this type of plastic pipe I would cut it, and protect the brick wall somehow, and try a larger pipe over the end of the cut pipe. As there is no pressure on the drain pipe it would be easy to get a joint fitting to push fit over the cut and re-unite it later on.

This was after spending two and three quarters of an hour last night listening to all sorts of messages on the British Gas Service helpline** before I got through to book a service visit. I couldn't afford to miss a live human at the end so it was something of a trying time - a bit like other's experience of Essential Classics perhaps. And I was offered an appointment on 12 March - not being vulnerable, having electric heaters and an immersion heater.
(**For some reason it wouldn't let me book a visit online!)

[oddoneout]

There is at least one British Gas video online which deals with this problem and demonstrates the solution; sorry I don't have a link as I didn't need the info, but should be easy enough to find given that there is increasing awareness.
Wonder how colder parts of mainland Europe deal with the issue? Probably 'by not starting from there'. I have a vague recollection of being told that draining into the existing plumbing(such as kitchen sink waste) is not permitted unless there is no alternative, to prevent the risk of blockage shutting the boiler down. I suppose in the scheme of things the risk of blockage in a kitchen sink waste is higher than the risk of an external drain freezing....

[Dave2002]

We had a new condensing (not combi) boiler installed in late 2016. Would not fire yesterday. Looking at the error code, and the installer's manual, it could relate to several things, including gas pressure. There is a procedure to purge the gas supply (no naked flames around, obviously) and I was thinking of trying that. But this morning when I was about to try it I noticed the condensate drain pipe, which is a push fit over a 1inch plastic drain pipe which goes through the wall and then down to an outside drain.

With a bucket underneath, about a pint of water came out after disconnecting the pipe - and the boiler then fired. So, I will empty the bucket at lunchtime, now collecting condensate and yes deploy a hair drier and then lag the drain pipe! If I had no other means, with this type of plastic pipe I would cut it, and protect the brick wall somehow, and try a larger pipe over the end of the cut pipe. As there is no pressure on the drain pipe it would be easy to get a joint fitting to push fit over the cut and re-unite it later on.

This was after spending two and three quarters of an hour last night listening to all sorts of messages on the British Gas Service helpline** before I got through to book a service visit. I couldn't afford to miss a live human at the end so it was something of a trying time - a bit like other's experience of Essential Classics perhaps. And I was offered an appointment on 12 March - not being vulnerable, having electric heaters and an immersion heater.
(**For some reason it wouldn't let me book a visit online!)

Hopefully you can now keep this problem under control, and avoid any charges. My "solution" was only temporary - but as the weather should improve from now on - with luck it won't recur for another year or two. I ended up with an old plastic box under the pipe, which I filled with about 5 plastic milk bottles filled with hot water, and I put extra lagging from earlier Hello Fresh food deliveries over the top, and a bit more improvised lagging to block the wind. All this after clearing the pipe by pouring hot water over it beforehand - about half a bath full I'd say! I did mention that hair dryers or fans would have been better, but would have required a long cable.

Interestingly the milk bottles were not frozen this morning, and the boiler was still running - and still is - so on this occasion the temporary solution has worked. Lagging by itself was insufficient - I'd already lagged the pipes having had problems in previous years.

Resetting the boiler is quite easy - and only takes maybe 10-20 seconds - though in our case it takes longer because of the trek into the garage - and clambering over junk to get to it. Anyway, maybe others have benefited from this discussion - and the end is in sight.

[Anastasius]

From another forum...the guy that posted this is an engineer par excellence and this is his permanent solution

When fitting our condensing boiler I took the 22mm pipe through the wall in a 40 mm sleeve to create an Insulating air gap and into a 68 mm gutter down pipe. The exposed length is less than 50 mm. The same scheme for the prv outlet. There is also a condensate Syphon which has to fill then drain out in a rush when full. No way that will freeze.

Not rocket science to retro-fit for a competent DIY'er

[gradus]

We use a fairly elderly wall hung oil boiler that seems to cope. There is no gas supply in the village so it's oil or solid fuel. In fact we also use a wood burner and an open fire but have switched to kiln dried logs which though more substantially expensive than buying 'seasoned' wood is considerably more reliable and much less work.
The down side of all this is the relatively high cost.

Anyone found a cheap effective electric system?

[BBMmk2]

A good friend of mine has a. Ice wood burning stove!

[Anastasius]

....
Anyone found a cheap effective electric system?

Is an oxymoron ! I'm afraid that there is no such thing. It's the running costs that are the killer. How well insulated is your house ? How draughty is it?

This is quite a useful link if you wanted to know why kiln dried logs give out more heat

https://www.stovax.com/kiln-dried-or-seasoned-logs/

[Dave2002]

From another forum...the guy that posted this is an engineer par excellence and this is his permanent solution

When fitting our condensing boiler I took the 22mm pipe through the wall in a 40 mm sleeve to create an Insulating air gap and into a 68 mm gutter down pipe. The exposed length is less than 50 mm. The same scheme for the prv outlet. There is also a condensate Syphon which has to fill then drain out in a rush when full. No way that will freeze.

Not rocket science to retro-fit for a competent DIY'er

I had a report of yet another person who had this failure this morning - but problems are receding.

Re the solution above - it'll probably work 90% of the time - but I notice that the end of my pipe which goes downwards into the drain can be exposed to the wind, as well as the cold. A small mound of ice can start there, and if that continues to grow then the problem will come back. My pipe end is also not very long. Lagging, which has worked in the past was not good enough this year.

Another solution is to box the pipework in - assuming that can be done neatly and easily.

Being British we'll probably rely on statistics - it won't happen again for another 5 years at least - maybe! Additionally as the spring and summer approach we probably (all) won't get round to dealing with this until the problem recurs.

[Dave2002]

A good friend of mine has a. Ice wood burning stove!

Where can I get some ice wood? Best wishes