our expansion pipe on top of the cylinder keeps freezing with the frosts we are having, its a pain as cylinder is on wet back and wet cant turn fire on while its frozen for fear of cylinder exploding. Any ideas on how we can stop the pipe from freezing, MTIA
bill1451,
Jul 10, 3:41am
Get some of that pipe wrap and wrap in that greasy tape that plumbers use, cant remember what it, s called, but any plumbers merchant will help you Mico, s etc or Bunnings, or that black spongy tube that plumbers use made of rubber foam.
freedreamz,
Jul 10, 3:52am
thanks bill, will get onto it.
shakespeare6,
Jul 10, 4:28am
Denso tape is what it is called plumbing or electrical wholesale have it.
biddy6,
Jul 10, 3:34pm
Measure the outside dia of the pipe,(the insulation comes in a couple of sizes) and get some of the split black foam insulation tubes from bunning etc, and get enough to wrap in the attic space as well as outside, and just use ordinary black tape to hold it together.
aredwood,
Jul 12, 2:44am
Get a plumber to install a pressure relief valve on the cylinder outlet. But keep the open vent pipe as well. This means that if the vent pipe freezes the relief valve will still work.
trade4us2,
Jul 12, 4:03am
I've put on the black spongy foam and pushed a PVC pipe over the outside to protect the foam from the weather. But the top part of the pipe is not insulated, however we never get a frost so hopefully the tank won't explode!
trade4us2,
Jul 12, 3:35pm
We just got a frost! How do I stop the top of the expansion pipe from freezing?
tweake,
Jul 12, 7:52pm
don't worry. the heat from the hot water will stop it freezing solid in auckland temps. but it doesn't hurt to cut down the heat loss. just measure the pipe diameter and go down to hardware store and get the pipe insulation.
trade4us2,
Jul 13, 12:09am
The overflow pipe is 10 metres long (because part of it is horizontal). I doubt that any hot water reaches the end of the pipe, therefore it might freeze. There was ice on the roof all around the pipe. I'll just turn off the hot water heater when it's a freezing night, then the tank can't burst.
tweake,
Jul 13, 12:47am
i wouldn't bother turning it off. never heard of one bursting yet. even when they had snow! if you think its a big problem change it to a relief valve setup. otherwise a bit of insulation wouldn't hurt just to cut down heat loss.
trade4us2,
Jul 13, 2:24am
Relief valves are unsuitable for the purpose they are sold for. I've had four relief valves or replacement springs (they go rusty) so I ripped out the valve and put back the overflow pipe that used to be on the house.
freedreamz,
Jul 22, 2:41pm
ok so the worst happened, big frost Monday morn, expansion pipe froze solid and cracked the top out of cylinder, not happy, neither is insurance company.
pauldw,
Jul 22, 2:53pm
Post #6 on the 11th was a plumber's answer.
tweake,
Jul 22, 4:58pm
well thats what insurance is for.
tho i'm curious why it hasn't happened before and is your setup any different to anyone else's in the aera ?
aredwood,
Jul 23, 5:55am
Outch! What exactly did the insurance company say? Since it was technically caused by the weather. Or do they know about this thread and are saying that you were negligent in using the hot water cylinder during the frost?
Note that the code says to use an expansion valve instead of a relief valve. I said to use a relief valve because they can control vacuum conditions as well as over pressure conditions. And a vacuum condition will occur if both the incoming watermain to your house and the vent pipe freeze. Because as the water in the cylinder cools, it contracts. And if neither air or more water can enter the cylinder. The inside of it will crumple as if it was made of cardboard.
aredwood,
Nov 15, 6:58am
An expansion valve will NOT control a vacuum condition.
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