The cross-linked polyethylene, commonly referred to as PEX, is a pipe popular for home plumbing. It is made up of colorful rolls of plastic tubing, which makes it quite aesthetic. Since it is made of plastic, the PEX pipe is not rigid; it is pretty flexible.
As with flexible objects, the pipe is bound to expand or contract depending on the weather. For this reason, it is a valid concern whether it is safe to use heat tape on PEX pipes.
The simple answer is yes, you can use heat tape on PEX, provided you follow the instructions provided by the manufacturer. This article provides more information about using heat tape on PEX, so read on.
Can You Use Heat Tape on PEX Pipe?
Despite its name, heat tape is not some kind of adhesive. Rather it is an electrical cable whose purpose is to prevent an object from freezing over by applying a certain amount of controlled heat.
Thus, you can use heat tape to prevent a PEX pipe from freezing during cold weather. Usually, people are concerned that heat tape would melt a PEX pipe since the latter is made of plastic.
However, you should note that PEX pipes are used on radiant heating systems. Therefore, it is unlikely that they would be destroyed by heat tapes.
Still, it is crucial to stick to the manufacturer’s recommendations when using heat tape on PEX pipes.
Different brands of PEX pipes have different heat limits, beyond which the pipe starts sagging.
To prevent this from happening, you should always maintain the temperature of the heat tape below the pipe’s heat limit.
Some PEX pipes have the heat limit indicated on them, which is convenient. You would have to be on high alert to ensure the tape does not exceed this limit. Alternatively, you can get a self-regulating heat tape.
What is PEX?
PEX was created in 1968 by a scientist called Thomas Engle. Engle’s idea was to come up with a strong and durable plastic. Therefore, he cross-linked different types of basic plastics and produced one more robust plastic through the process of radiation.
PEX is used to create pipes that are commonly used for radiant heating systems. As such, PEX is malleable, making it flexible enough to take any shape without breaking.
Also, it is quite sensitive to UV light from the sun, and too much exposure to sunlight may lead to the plastic disintegrating.
PEX’s flexibility makes it easy to install, which is one of the reasons it is popular for home plumbing. Furthermore, the flexibility makes it ideal for extreme weather as it allows room for expansion.
For instance, when it is cold, the pipe expands accordingly when the water inside starts freezing. This reduces the chance of the pipe freezing. Also, this is where a heat tape comes in, as it also prevents a PEX pipe from freezing over when it is cold.
Is PEX any better than copper? Here is a video with detailed comparisons:
Types of Heating Tapes
Self-Regulating Heat Tapes
These are the most widely used heating tapes. The tapes have a heat sensor, which will monitor the prevalent temperature and self-adjust.
When the temperatures are above the freezing point, there is no heat emission. Not only is this convenient and safer, but it will also help you save a few dollars on your energy bills.
Thermostat- Controlled Heat Tapes
TCHT is a hybrid version of the self-regulating heat tape. It basically works the same but has a thermostat to regulate the temperature.
It’s important to note that the thermostat is separate from the tape and requires its own installation kit. For optimum functionality and accurate readings, you should place the thermostat in the coldest area directly on top of the PEX pipe.
Manual Heat Tapes
These are more traditional tapes that require you to plug or unplug them from a power source manually. It would be best if you remain vigilant when using such tapes to prevent igniting fires or wreaking havoc on your property.
These tapes tend to overheat if you leave them plugged in for long periods while the pipe temperature gets warmer.
How Does a Self-Regulating Heat Tape Work?
A self-regulating heat tape looks like a heavy-duty TV antenna dual-lead cable of the older generations. You should have a house current of 120V to run a self-regulating heat tape.
Essentially, a self-regulating heat tape works by heating only when it needs to, to ensure that the temperature of the PEX pipe stays above freezing point. It has two conductors which are only several millimeters apart and are enclosed in a plastic sheath.
Between the conductors are several positive temperature-coefficient thermistors. The thermistors are made of metal oxides which can regulate the required temperature. In this case, they hold a temperature right above the freezing point and maintain it there.
When a part of the pipe starts falling towards the freezing point, the thermistors in that part of the tape conduct current and self-heat to raise the temperature.
Once they stabilize the temperature again, the thermistors stop conducting, and the heating stops. Thus, they do not get too hot to the point of melting the plastic.
In the warmer parts of the PEX pipe, the thermistors do not conduct any current, so there is no unnecessary wastage of electricity. Thus, one vital pro of a self-regulating heat tape is that it can read its temperature the whole time.
Also, it is simple to use and way more effective than manually controlling the temperature of a heat tape. In addition, it is an economical method of protecting a PEX pipe as it conserves electrical energy.
How To Use Heat Tape on PVC?
First, you ought to look to ensure that the heat tape is labeled safe to use on PVC. Also, check whether the tape has a temperature regulator. If these conditions are met, then you are clear to use the tape on a PVC pipe.
Heat tapes are attached to PVC pipes by wrapping the former onto the latter. Wrap the tape around the pipe in a spiral motion, starting from the electrical outlet.
Starting the wrapping action at the electrical outlet will provide you with adequate length to plug the tape without much trouble.
Ensure that the tape covers all the areas that could be exposed to freezing. As you do this, leave some space between the wraps, as wrapping them too close to each other can result in overheating.
Also, avoid wrapping the tape on itself as this could cause a short and possibly, a fire. The end of the wrap should not touch the ground because it could get exposed to moisture.
In addition, you should check whether the heat tape is for use outdoors or indoors – they are usually indicated. If a tape is for the outdoors, use it outside.
Similarly, if the tape is made to be used indoors, then use it inside a building or in protected areas.
More importantly, avoid extension cords at all costs. Always plug the heat tape directly into a three-prong GFCI outlet.
Tips for Using a Heat Tape on A PEX Pipe
Before you can install a heat tape on a PEX pipe, here are a few things you need to consider:
- The Size of the Pipe – This will primarily determine the correct measurements of the heat tape. Before you head to the store, measure the pipes so that you have enough tape, especially if you will be wrapping them. The length of the tape should be significantly longer to cover the entirety of the PEX pipe.
- The Flexibility of the Tape – The tape should fit snuggly but not rigidly. It should allow for some degree of maneuverability for the PEX pipe to expand and contract with the temperature fluctuations.
- Plugs – You attach these at the ends of the heat tape. You can have multiple plugs depending on the size of the tape. For a first-time installation, we recommend you buy a heat tape kit rather than raw heat tape. It may be slightly expensive but comes with pre-attached plugs for easy installation.
Frequently Asked Questions
At what temperature does a PEX pipe melt?
Check for maximum temperature limits as indicated on the pipe. While the highest temperature will differ from one manufacturer to another, 200 degrees Fahrenheit is the general limit. Exceeding this temperature will cause the pipe to melt.
Are there PEX pipes for hot water supply?
Different colors of PEX pipes serve a specific purpose. They come in red, blue, and white, and these color codes are constant across all manufacturers.
Red PEX pipes are used for hot water supply. Blue is for cold water lines, while white can be used for both hot and cold water.
The color codes are only for convenience purposes but are built exactly the same – so they do not affect the performance of the pipes.
Is PEX a good choice for domestic plumbing needs?
Yes, PEX is excellent for your plumbing needs at home. It is easy to install and flexible enough to withstand different temperatures, including freezing cold. They are more withstanding compared to pipes made with copper or PVC.
How do I fix the tape on the PEX Pipe?
Sometimes wrapping the tape around the pipe won’t hold for long. You can use electric tape or a zip tie to fasten the tape. Adhesive heat tapes are available for more permanent installations.
Final Thoughts
You can use heat tape in PEX pipes, provided you adhere to the temperature limits. PEX pipes have maximum temperatures beyond which they could melt. Heat tapes prevent the pipes from freezing when it is very cold.
Self-regulating heat tapes are the best for this purpose as they are simple to use and are economical as they conserve energy. Ensure you follow the manufacturer’s instructions before you wrap heat tape on your PEX pipe.
