Heat tape question

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rwhite

Minister of Fire
Nov 8, 2011
1,986
North Central Idaho
I probably know the answer but I'll ask anyway. I have a floor drain in my shop that tends to freeze. Melting snow etc just makes an annoying puddle. The drain is in concrete and just runs outside the shop wall and empties on the ground. Ii is covered by a 1/2 barrel outside so it's not packed under snow. I don't feel like digging out 4 feet of snow to use a hair dryer on it. Can I run a heat tape inside the pipe? Any other ideas to keep it from freezing? Its 2" black PVC. Not sure how deep since was here when i bought the house.
 
Right now I got a trough heater just sitting in 6" of water hoping it will warm enough to thaw it out.

Edit: Gave up on the trough heater. After a few hours it had done nothing. I dumped about a cup of salt down the drain. Ill see what happens in the morning. I'm thinking I might try a mesh kitchen strainer basket in the drain and keep some salt pellets in that. Maybe it would make enough of a brine to keep it from freezing.
 
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I probably know the answer but I'll ask anyway. I have a floor drain in my shop that tends to freeze. Melting snow etc just makes an annoying puddle. The drain is in concrete and just runs outside the shop wall and empties on the ground. Ii is covered by a 1/2 barrel outside so it's not packed under snow. I don't feel like digging out 4 feet of snow to use a hair dryer on it. Can I run a heat tape inside the pipe? Any other ideas to keep it from freezing? Its 2" black PVC. Not sure how deep since was here when i bought the house.
So most 3 and 4 story ski resorts run "heat trace" across the roof overhangs and down the downspouts, with a loop showing at the bottom j-bend downspout outlet. With that said, it's probably too late to install now cause you have an ice blockage, which most heat trace won't be hot enough to melt (3 watts per foot from memory).

You can try a DIY "hot water drill" design, where you take a 20' roll of plastic tubing, hook it to a fish tank pump, drop the pump in a 5 gal pail of hot water, and snake the tube down the pipe until you hit the ice block. Turn on the pump and advance the tube as able. Suck up the return water backing up the drain with your shop vac. If you got a hot water tap it's even easier, but more messy.

I learned that trick many years ago from a plumber in VT who got our vacation cabin well working within 20 minutes of arrival. That saved our week and I tipped him generously!:)
 
You can run a heat tape inside the pipe they make one that runs in a pipe or you can use the standard heat tape.. I would suggest adding or plugging it into a GFI receptical. start running it up from the outside and it will melt out the ice so you can shove it in all the way. I have thawed out frozen trains in about 20 min. For stubborn ice i have a old hand steamer for cleaning. I hook a clear tube up to it and shove it in the hole. It will actually pull itself in as it melts the ice. Iv cleared about 40 feet of frozen waterline in about 5 min..
 
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I finally consented and dug out the snow. That took 2 hours. Then about 10 minutes with a hair dryer to unthaw the drain. Luckily the wife was gone as she doesn't take kindly to me burning up her good hair dryers on pipes.
 
Yes calcium chloride and other various ice melters will work if the soil downstream can handle it. If it is a reoccurring problem like a gutter, heat tape works. The trick is that the heat tape doesnt have to be left on 24/7. It only needs to be when freezing is likely to occur. One of houses I grew up in was in a development that was built in the seventies and every house had ice damming issues. We installed the cables on valleys, the lower edge of the roof and down the gutters. We found that if we just turned them on on sunny days when there was snow on the roof for a couple of hours, that would get the melt water running and then we could turn them off. We hooked them to the front porch light circuit to remind us to turn them off that night if we forget to run them off as they do eat up a lot power for nothing. I expect they could be put on timer with photocell in series so they would go on automatically. Generally when a drain freezes its not sloped properly and probably has a low spot.

The other trick is to get some stiff tubing and a source of hot water. All it takes is a 1/4" tube like PEX. Hot water is run through the tube and stuck down the pipe. It melts a hole in the ice in the drain.and the meltwater flows back out the drain to the opening until it melts through. Steam works better but its more dangerous and metal tubing is needed. I have a box of dekabon (synflex) which is aluminum tubing covered with nylon. We used it to melt a buried water line once under road about 700 feet in from where we could feed the tubing. Its stiff enough to push up the pipe as the hot water we were pumping through it was flowing back and was acting as a lubricant. Our facility normally used it for temporary instrument tubing and they didnt want it put back in stock as it was "dirty" so I carefully rolled it up, threw in in the box and its sitting in my garage. (the perks of being a project manager on a remote site).
 
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gutter heat tape will work fine and it's 9 to 10 watts a foot depending on the brand. if you run a loop the wire can't touch the other or the will melt so one line in from outside on a gfi outlet with a switch. the flat heat tape for outside wrapping of a pipe i don't think it's rated for sitting in water.
 
U would think it would be rated... it's to be used around water with the possibility of being under water.. I have about 30 of them in service where the tail is regularly under water. I have 1 fail about every 8-10 years

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it can get wet but not sure that it can continuously sit in water they are meant to be wrapped around a pipe and not in it or sitting in a puddle. you would have to look in the directions for the tape to be sure. and it should be on a gfi receptacle. the new models made for roof and gutters are better that they use to be. few years back it would have to be hook into a 30 milliamp gfi because they would pop the standard 5 milliamp gfi. now it ok to install on a reg 5 milliamp gfi
 
The industrial self regulating heat tape is (or was) rated for full immersion use. Its slick stuff, the chemistry of the product itself regulates the temperature, If its above freezing, it barely pulls any power as it gets colder the resistance goes up and if pulls more power. The other big plus is that it can be wrapped over itself. If regular homeowner grade heat tape is wrapped over itself it will burn out quickly.

Working in a pulp and paper mill that occasionally saw minus 30 F and had very negative pressure buildings due to lots of exhaust fans we went though reels of heat tracing.
 
Thanks for the tips. I think I'll try and slope the outside 10ft of pipe this spring. It only seems to freeze where it comes out of the wall so I may just put a heat tape on that section and plug in as needed. I usually don't have an issue for 90% of the winter. Just when we start getting into freeze/thaw cycles that stuff starts melting and the drain is used. The shop was built with the door on the eave side so all the snow slides off the roof in front of the door then melts and runs under the door.