Frozen household water pipes can be an expensive and messy problem that can be prevented by installing heat trace on your pipes.
With the cold temperatures across New Zealand, we have had customers calling to find out about heat tracing their pipes. We recently helped a customer in the South Island prevent her water valves from bursting after freezing. For her situation, here is the advice we gave:
What do we use?
We recommend using a self-regulating heat trace cable like Thermon CSR-620. You will still need a thermostat to turn the heat trace on and off. A simple way would be to maintain the water at say 10deg.c this gives you a bit of security when temperatures drop. Remember that water valves will be the coldest part of your application, and could get colder than where you may place the thermostat probe.
How much will it cost?
For a couple of meters, running costs will be less than running a light-bulb. It would not run all the time even at -12deg.c.
How do I control it?
You don’t have to control the heat trace if you don’t want to, but I would advise using some form control for a couple of reasons:
1. If you were to rely on yourself to remember to turn it on and off, personally I would forget. If you forget, you might have the same problem where the valves burst again.
2: Control is autonomous and you would never have to worry about it again.
Any small controller would be fine and should be able to switch the heat trace on and off directly.
Do I need insulation?
Yes, insulation should be used on both the valve and the pipe.
Valve allowances of approximately 20cm should be insulated if possible or the heat will be wasted and escape to the atmosphere.
Heat tracing runs along the pipe so the insulation will keep the heat in. The thicker the insulation the more heat that will be kept in, and less the heat trace will have to work to maintain the pipe from freezing.
How do I install heat trace?
Heat trace is best installed by an electrician. They will tape the heat tracing on with aluminium tape. SX-Term-1BC is needed to seal the cable off from water getting into it. One end is an end seal, and the other end seals but also enables it to be connected to the power.
Your electrician can take this heat trace directly into a Junction Box and connect that into power or they may use heat shrink and crimps. Then they should use thick-walled glued heat shrink over the heat trace and power cable, and connect it into the power supply.
Each household will have different heat tracing needs. To find out about heat tracing your home, talk to your electrician, local electrical wholesaler or call Vaughan on 021 401 444.