Is the ice in the vertical section or the near horizontal part?
Fit a wider bore pipe if the former.
Got up this morning, ran the hot water tap and couldn't get hot water, at this point my day started to go downhill. Central heating boiler problems are an absolute pain, always occur at the least convenient time and like many I rely totally on a combi boiler to provide heating and hot water so when it packs up I`m screwed. Boiler's only 18 months old, problem turned out to be the condensate drain line blocked solid with bloody ice. Fortunately it's v. easy to get to, with approx. 3 feet running vertically down the bungalow wall into a drain. 15 mins with a hair dryer fixed it and the boiler's now running OK again.
What I can`t work out is how to prevent this happening again, ideally the condensate line could've been run into the drain pipe from the dishwasher indoors, but now the kitchen's been refitted it's a sizeable job to modify so I`m stuck with the vertical pipe outside. Thought about lagging it but I`m not convinced it'll help, the temperature of the line follows the ambient cycle, warming above freezing (usually) in the daytime and dropping at night, if it's lagged it won't warm up as readily.
After a couple of days of sub-zero temperatures with no sunlight the line has blocked and I see no reason why it won't happen again, despite it being a simple problem to understand I`m struggling to find a solution.
If this was in an industrial setting the line would be trace heated and lagged, problem solved, I find domestic plumbing frustrating in this respect !.
All suggestions welcome. Modifying the line to make it easy to dismantle and allow the condensate to drip freely when the temp is sub-zero is one answer but it's hardly subtle.
Is the ice in the vertical section or the near horizontal part?
Fit a wider bore pipe if the former.
You could get someone to fit some type of heat tracing.
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For the price of a piece of lagging, I’d give it a try first. Whilst it won’t warm as quickly, it may be just enough to keep the temp above freezing inside, so then won’t have to thaw.
Modification to remove bad required would be my other approach, but only if needed.
It’s not all great having it inside either. Ours had a slight leak at a joint & required so many pieces of kitchen cupboards to access as was behind the cabinet and of course in the tightest, hardest to reach place.
As an aside, would a kettle be quicker than a hair dryer? Having just used the layer to melt the ice on my car window so it would drop as I left the handle and clear itself from the roof, it seemed to take forever.
Lag it, and run some heat-trace down the inside (from inside at the boiler - down as far as you can inside 2-3m of cable will do. Use a timer on the plug, but it is self-regulating anyway.
But, I would run the tail of the heat-trace out the bottom of the pipe and seal the exit. Reason is that the condensate is mildly acidic - so you may have trouble sealing the end of the heat-trace against that.
https://www.ebay.co.uk/itm/122049395...Bk9SR4qEs-WiYQ
Could you construct a crude wooden (temp) oblong box filled with loft insulation to cover the pipe during the couple of months it’s that cold?
Or a length on white guttering filled with insulation with an end cap on the top?
It appears there are some trace heating kits that are OK to use with plastic pipes, something simple that can be controlled from the kitchen would suffice but the fridge freezer will need taking out to fit. Id prefer something low voltage running off a transformer but haven`t found anything. Anything using direct 240v needs doing carefully and thinking about.
Judging from the icicles that came out, the pipe definitely froze in the vertical section.
Pouring hot water on the pipe is a way of clearing it but there's a risk of cracking the plastic due to thermal stress. I was surprised how much ice had formed, I think it's built up over a few days. Took a while to fully thaw out, plastic's a poor conductor of heat so I ended up using the hair dryer for a good 10 mins. Not ideal.
Might try some lagging and gaffer tape as a short-term measure. By coincidence I've spent the last 2 days lagging central heating pipes in the loft to eliminate heat losses, the pipe runs are approx. 25' and weren't lagged as thoroughly as they should be when the boiler was fitted. One of these jobs I`ve been putting off doing for a while.
Make sure any lagging is waterproof closed cell.
As has been said above, as early as possible in the run, use a larger diameter pipe, 32mm waste pipe will suffice.
Assuming it's the nearest pipe in your photo that's looks like a smaller bore than usual. Less diameter equal less ice build up to block it maybe?
Mine blocked during the beast from the east, but it followed a very shallow path from our attic to the rainwater gutter. The problem was ice forming in the gutter like a stalagmite from the pipe outlet which ultimately built up and into the pipe. I couldn't stop it reoccurring except by sawing the pipe off before it reached the gutter, the only remedy actually during the storm. Still a nightmare job up a ladder durimg that storm.
Its completely rerouted now and stops about 4 inches above a drain, so far so good.
Move the pipe inside
I had that problem for years. Thought we solved it last winter with much larger diameter pipe. Minus 12 in Manchester last night meant that isn’t a solution. It was lagged as well. Was at B&Q by 8 am. Got the fitting closest to the boiler pulled apart and added a new fitting and pipe that dangles inside to a bucket. Fills quite slowly and a temporary fix whilst we suffer this very cold spell
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Ours is a 32mm diameter pipe with a condensate trap on the inside - never had any issues.
When you look long into an abyss, the abyss looks long into you.........
Cant it join the other pipe inside, before it goes through the wall?
Started out with nothing. Still have most of it left.
We've already done this in the Check your outside pipes thread:
https://forum.tz-uk.com/showthread.p...-outside-pipes
If you tee-off your run-off pipe from the boiler into a container of some sort it will eradicate the problem. When the outside feedout is blocked by ice the condensate has nowhere to go so this mod is a failsafe costing pennies. I'm just waiting for a pic to illustrate the solution.
It goes into the bucket. Be careful because the resultant liquid is acidic.
Last edited by Harry Smith; 15th December 2022 at 17:54.
I used the grey foam pipe lagging you can buy at diy stores at my last house. Changed the lagging after 6 years when it started deteriorating. Never had an issue in the eight years we were there.
Is there not a minimum diameter now to stop exactly this and that looks too thin.
Plenty of lagging on Amazon.
Think most options have already been covered here but for what it’s worth.
We use 32mm for outside condense runs, if you do this and use a suitable condensate lagging it SHOULD be fine. If you want to leave and use the existing pipe, the most successful option we have seen is and boxing in with lagging / insulation.
Under extreme weather conditions there is always a risk of freezing and running internally should always be the preferred method.
As already said, trace heaters can also work very well.
Just returned home after an evening of 'socialising', taken the dog for a short walk, it's absolutely bitter cold outside! Hopefully this problem won't re-occur but the ambient temp is definitely sub-zero.
Had a think about this problem, if I drill a small (2mm) hole in the top of the protruding horizontal section of pipe this should prevent the boiler sensing a blockage, even if the vertical leg becomes blocked with ice. Can`t see why this shouldn't work as a short-term solution. If the 1 metre long vertical section becomes totally full of ice we'll be into a full-blown Arctic winter...........I thought global warming was supposed to avoid this scenario!
Thanks to all who've contributed with comments and suggestions.
Acidic water may spray on the brickwork…………
that might be an issue?
Yes, split and usually self-adhesive. Look at these https://amazon.co.uk/s?k=condensate+pipe+lagging
Obv. choose one suitable for outside.
What I don't understand is why this problem isn't accounted for at the time of fitting?
Surely it's pretty common over winter so why not ensure the pipe is properly protected against freezing in the first place rather than leave the homeowner to figure it out while sitting in their freezing cold house?
Any heating engineers care to shed light on this?
Another current thread on same topic https://forum.tz-uk.com/showthread.p...-outside-pipes
We use trace heating at work. It's normally about 5w per mtr and you can cut and seal one end and make off the other to accept a plug with shrink-wrap.
Obviously fused down correctly.
I used a full coil once in the filter of a koi pond to keep the chill off.
It's easy stuff to work with providing the ends get the correct seal
In my old house there was something like this installed:
https://www.tlc-direct.co.uk/Products/BNPW03.html
The good thing is that the heating of the pipe starts when temps are below 3-4 degrees - regulates itself. And did work very well.
You can keep it unplugged most of the year, then on when temperatures drop.
I used pipe insulation on mine after a similar event in the beast from the east and, fingers crossed, it has never repeated since doing that. Never been as cold as that mind you but I am pretty confident.
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Just happened to me for the first time this morning. Only noticed as the utility room where the boiler etc are located had a wet floor.
Wasn’t sure what caused it but thought to look outside and sure enough could see the end of an ice plug at the bottom of the pipe.
10 mins with a hair dryer and then a thin drain cleaner up the pipe and the block of ice fell out.
Now re-reading this thread to work out a long term solution.
First time this has happened though so maybe we’ve been lucky.
Obviously I'm not a heating expert but after recent events 'gifted amateur' might be on the horizon lol.
Plumbers do know about these problems but some are lazy buggers and others are loathe to suggest cost increases on already expensive builds. Also if the refit is replacement of an old boiler and/or immersion system (also warm air system as in the case of my Daughter's house) there is just not the provision for supplementary drainage.
My Worcester Greenstar combo boiler stopped working yesterday evening - error code 227. The boiler is 12 months old. I suspect it is a frozen condensate pipe (-10 last night) which runs down the outside of the house from the first floor to the ground, and is not lagged. I don’t fancy trying to thaw several meters of pipe using a hair dryer. I can’t reach the top half anyway. I think I am going to have to suffer until the thaw on Sunday.
It is really cold in the house. No central heating, no hot water. Fortunately I have got two small oil filled heaters.
If it's any consolation, I had a problem a couple of years ago with a WB Greenstar boiler still in warranty, and WB were brilliant, sending engineers the next day and fixing the problem. The female engineer was pretty fit as well, which was a bonus.
Good luck. At least the weather is set to become milder over the weekend.
If you can identify the outlet pipe, seperate it inside the house - assuming it is a plastic pipe like ours - then attach some hose or pipe to empty the condensate into a bucket. At least you can temporarily get your hot water back until a more permanent solution is possible.
Thanks for the suggestions, I will have time tomorrow to look at it. I am waiting until the better weather on Sunday to see whether I need to call out an engineer - I imagine they are very busy now, and I won’t be able to get anyone for some days anyway.
Yep mine has frozen too. Well, the condensate pipe itself hasn’t, but the plastic pipe work it drains into outside has. This is shared with the washing machine waste and caused a minor flood earlier, thankfully the Mrs was in the vicinity and managed to prevent disaster.
I have a bit of a workaround so we can still have shortish blasts of heating and hot water. But I’ll work out a proper fix when it has all defrosted on Sunday (hopefully!).
I’m over this cold blast now. Bring on our usual wet, mild Christmas!
I had this very problem and my plumber suggested a pump. All the condensate drains into the pump which is located below the boiler indoors, once it full the pump kicks in and it goes thru the pipe under pressure to the outside drain. No residue is left in the pipe so no icing up can occur outside of the building, easy to install about an hours work and the pump was around £100.