Frozen Internal Mains Water Pipe

[chuckalicious]

Quick question:

woke up this morning to find we had no running water (central Scotland - think it got to -10 last night).

Found one running tap, in the utility room. This runs at full mains pressure.

The mains comes in through the utility room and feeds that sink, then goes up an external wall (the pipe is on the inside but behind plasterboard).

From there I *think* the first place it feeds is the bathroom. Nothing in the bathroom works.

So to me that says the pipe is frozen somewhere as it goes between the sink and the bathroom.

I intend to pull down the plasterboard (it's in a cupboard) and see if I can thaw the pipe, assuming it hasn't burst.

I've also turned off the water mains at the stopcock as I'm at work all day.

My question is this:

assuming the pipe has frozen at the point I think it has, what is the best thing to do? Should I leave the pipes exposed to the rest of the room and let the room heat keep the pipes unfrozen, or should I lag and recover? As it's an external brick wall that the pipe is attached to I know it will get very very cold and so don't know if lagging will help in extended periods of cold.

Thanks

 

[studips]

i'll assume your whole house is on mains and is not tank fed, it doesn't matter how quickly the ice melts within reason - copper is quite good at stretching, but you can't keep freezing it as eventually it will fail. i'd put a heater near it and let that play over it, or turn the water back on and run the upstream taps - partial thawing will allow water flow and this can help melt the plug of ice.

to prevent the problem reoccuring, some armaflex would be a good idea if the dish water freezes overnight, but other than that ambient heat from the house should keep it clear. trace heating tape is a bit overkill if you don't mind having the pipes on show.

 

[chuckalicious]

That's right, everything is mains fed.

Yeah - the thawing part I'm not so concerned about, it's more why the pipe froze and how I can stop it.

So would you suggest leaving the pipes on show? I don't think the dishwater freezes overnight, but the room can be very very cold during this type of weather.

 

[studips]

just leave them exposed, if anything pop some armaflex around them or something behind to stop the wall drawing heat off the pipes.

 

[chuckalicious]

thanks. I will do as suggested and leave them open to the air.

Should be fun ripping out the wall tonight Just what I want to be doing on a Friday night!

 

[cumbriahandyman]

Deleted, wrong thread

 

[chuckalicious]

So I've cut some decent sized air holes in the wall and can clearly see the unlagged pipes.

turned water back on and all seems to be flowing correctly.

Will be interesting to see if it freezes again. I assume if it does then it's not that site that's the issue.

Out of interest, our Worcester Greenstart CDi had errored (I'd left it on all day). I'm wondering if that was due to the water being turned off at the mains, although I thought it was totally sealed and didn't rely on a constant mains pressure.

reset and it seems to be running. Fingers crossed!