Frozen condensate pipe

gjn

I have a frozen condensate pipe. It's on the first floor, about mid-window height. What's the best way to fix it?

I'd normally phone for an engineer, but it doesn't seem to be a problem with the boiler itself from what I can gather.

Gareth

spadoosh

You should have a plastic pipe coming out from your boiler somewhere, can go outside or to the sink waste. Pour hot water on it. Ill let you worry about how youre accessing it.

If its still struggling it could be backlogged with water.

You should have a flexi pipe connecting to the plastic pipe that goes outside/sink.



Disconnect it and be ready to catch some water. Make sure you reconnect before firing up the boiler again.

bris

You pour hot (not boiling) water over the pipe until it clears, if safe to do so.


Boil the kettle a few times but as said let it cool slightly before pouring on the pipe.


You can also apply heat with a hairdryer etc but please don't do that if its still snowing.

gjn

Thanks for the info and diagram. Do you think it's possible to defrost it from the inside, perhaps through the disconnected pipe?

How much condensate (it's just water, right?) comes out when the boiler is on? Can I divert it into a bucket while the weather is like this?

daveyjp

The water is slightly acidic, no stronger than vinegar. You can let it drain into a bucket as an interim measure.

spadoosh

gjn wrote: »

Thanks for the info and diagram. Do you think it's possible to defrost it from the inside, perhaps through the disconnected pipe?

How much condensate (it's just water, right?) comes out when the boiler is on? Can I divert it into a bucket while the weather is like this?

In theory i cant see why you couldnt just run the hot water though from where you disconnect the pipe, although accessibility could be an issue.

Its not just water, it collects some CO2 whilst its being burnt so is slightly acidic hence the need for plastic piping and not copper. Nothing too dangerous though, its water and carbon dioxide mainly.

Depends how much is in there but a typical bucket will hold all of it coming out for the initial drain.

As for leaving it to drain in a bucket its an option that should prevent it freezing. The issue is if the condesate pipe trap has lost its liquid it will vent combustion gasses (carbon monoxide) through the pipe. Id say make sure you have a working and tested CO alarm if going with that. Its not overly likely to happen as the trap is usually inside the boiler and thus normally requires someone wanting to empty it for it to happen but better safe than sorry.

Water should keep coming out at a fairly slow rate, it wont be gushing so if you do drain it to a bucket youll need to keep an eye on it, probably emptying every day.

VfM4meplse

bris wrote: »

You pour hot (not boiling) water over the pipe until it clears, if safe to do so.


Boil the kettle a few times but as said let it cool slightly before pouring on the pipe.

I saw the same message on social media but thought it was a hoax. Isn't there a risk of the pipe cracking due to rapid expansion? (I speak as a scientist with theoretical knowledge only - happy to admit my status as DIY novice).

SuzieSue

VfM4meplse wrote: »

I saw the same message on social media but thought it was a hoax. Isn't there a risk of the pipe cracking due to rapid expansion? (I speak as a scientist with theoretical knowledge only - happy to admit my status as DIY novice).

That's why it mustn't be boiling water. It has worked for us twice this week.

calleyw

VfM4meplse wrote: »

I saw the same message on social media but thought it was a hoax. Isn't there a risk of the pipe cracking due to rapid expansion? (I speak as a scientist with theoretical knowledge only - happy to admit my status as DIY novice).

If you go on youtube there are videos from worcester bosch and BG telling you to do this. With hot and not boiling water

I did that and used a electric heater to heat the porch up. Not sure which it worked but I now have an boiler that works.

Yours

Calley X

peachyprice

VfM4meplse wrote: »

I saw the same message on social media but thought it was a hoax. Isn't there a risk of the pipe cracking due to rapid expansion? (I speak as a scientist with theoretical knowledge only - happy to admit my status as DIY novice).

Ice expands more than hot water, that's why frozen pipes burst, the ice breaks the pipe, the pipe leaks when the ice melts.

It's rapid temperature change that causes glass to break if you pour hot water on it, the same doesn't happen to plastic or copper.

Ectophile

VfM4meplse wrote: »

I saw the same message on social media but thought it was a hoax. Isn't there a risk of the pipe cracking due to rapid expansion? (I speak as a scientist with theoretical knowledge only - happy to admit my status as DIY novice).

Modern plastic pipe is pretty robust. I've been regularly tipping near-boiling water over my condensate pipe for the last few days, and nothing bad has happened.

I do wish that plumbers would stop installing condensate pipes outdoors. It's a rubbish way to do it. Unfortunately, that's the way it was installed when I bought the house. With a bit of extra effort, it could have been run into the bathroom, and would never freeze then.