heat tracing well water line in vermont

fitter1 · Aug 28, 2016

In order to have running water this winter at my camp in Vt. I need to dig up and replace the water line. I want to heat trace, insulate and encapsulate in 4" pvc. Now the well company I had installed the well say's I cannot bury heat tracing under ground. I'm at a loss for words. Because of ledge, I'm only 1-2ft. under ground @ 100ft. in length. Can any Green Mountain men up there shed some light on this problem. I'm off grid. Ken

Billrog · Aug 28, 2016

Because of rock some of my 1,200' of water line is only 8 to 12" deep but it has never froze in the last 25 years. I laded 12" wide 1.5" Styrofoam over it before burying. 2' wide foam would be even better & I'm not so sure that even sleeving it in 4" PVC wouldn't prevent freezing.

SPYDERLK · Aug 28, 2016

Here.

McMaster-Carr

...Click "Self Regulating Heat Cable". You are enclosing in conduit so theres no underground contact. This stuff actively adjusts to heat needs at every point along its length. The heat rating is nominal for max steady output but it usually throttles itself way back. The HD 3Watt per foot version should be fine, taped straight along your water pipe, itself inside a seamless run of 2" black poly. ---The heat tape never gets above 150F.

CCWKen · Aug 28, 2016

Now the well company I had installed the well say's I cannot bury heat tracing under ground.

Did you happen to ask why? Unless there's some local restrictions, I can't see why not. It's been done since the 1930s. There's even an IEEE standard for it.

The only concern I would have is the draw on your "off-grid" supply. If you figure 100' of straight line heater wire you're talking about 700 Watts. If the pipe is wrapped, length may double as will current draw. If you use the self regulating wire, the inrush current will be much higher though. That's the draw back of self regulating wire.

How do you heat your cabin? Another possibility is using a geothermal system to heat the pipe.

fitter1 · Aug 29, 2016

Thanks for your input guy's. Preferably I'd like not to rely on the heat trace but will put in anyway while the line is dug up. The well co. cannot quote me why not. Off grid living sucks. I'm on my third generator and have a small 2500w solar system. I've thought about getting a diesel, 1800rpm, water cooled genset and running an under ground heating loop. Now I'd need two fuel supply's. My neighbor had signed off for a power right of way and power co. had staked out 5 poles, then her son moved in and shut it down. Needless to say we now don't get along. Might be time sell. Yeah, I'm on a rant.

PILOON · Aug 29, 2016

Been there, done that!
We are in Quebec, north of Montreal and it gets cold in winters.
On our lake there is minimal soil covering the bed rock in many places.
I have installations that are merely 1 ft deep and heat 'tracing wire' is the solution.
One installation is 12" deep with tracing wire taped to the water line and the line inside of 4" pvc pipe with the pipe covered by 2" pink foam insulation board.
That line never froze even with the tracing wire disconnected. Theory was that the warmer airs would circulate in the 4" pipe to even out the temperature. It worked.
Old time locals even merely laid 12" hemlock planks over their water lines to prevent frost from attacking the lines and it worked.
Instructions were to never walk over the water line as compacted snow allowed frost to penetrate.
Loose straw over the water line (covered with plastic sheeting) also works.
Frost line is considered to be about 4' in this area.
Tracing wire is sold in 2 types, 3 watts/ft and 6 watts/ft.
The 6 watt version will thaw a frozen line while the 3 watt version will not. Tracing wire also comes in 110 VAC or 220 VAC depending on available power. I know of installations that are over 300 ft long and operating for over 25 years without any problems.
My preference is for 6 watt/ft installed inside of the water line. (they sell special fittings to do this)
For an ultimate system you'd also use a GFI circuit for your tracing heater circuit.

Had one installation that used 3 watt/ft that suffered a power failure and we had to wait 'til spring to restore water supply, hence using the 6 watt in later installations.
Note that the modern tracing lines only heat in the zones that need heat and therefor draw minimal current.

nybirdman · Aug 29, 2016

I had that problem one time;not fun.My weld driller installed a Heat trace "inside the line",I didn;'t know that they made such a product.Don't remember the name of it but it works well.

Egon · Aug 29, 2016

Just some pictures of various heat tracing systems.

[video]https://www.google.ca/search?q=insulated+heat+traced+pipe&client=safari&hl=en-ca&prmd=isvn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwib1qCpkOfOAhWKvRQKHT8UAqcQ_AUIBygB&biw=1024&bih=681[/video]