What Is the Maximum Safe PEX Tube Temperature?

PEX tube on a blue background.

PEX tube material is durable under the extremes of temperature and is a great material for other applications and hot water. The PEX tube is intended for hot and cold potable water distribution systems.

Maximum Safe Temperature

The PEX tube can withstand a maximum heat temperature of 200 degrees Fahrenheit. In a plumbing project, the PEX is able to stand a maximum heat of up to 180 degrees Fahrenheit. Usually, the highest temperature limitation is listed on the PEX tubing in small prints. All of the PEX tubing systems are tested, and you can use them with the standard P and T relief valves, which can be used at 210 degrees Fahrenheit.


Green PEX on the ground.

The strength and flexibility of PEX tubing make it the most ideal material to use for piping. Not only can it withstand a maximum heat temperature of 200 degrees Fahrenheit, but it can also withstand temperatures below freezing. It is widely used in cold and hot water plumbing systems, radiant hydronic heating systems, and applications for snow melting. PEX tubing is popular to use and so significant that it is even used in refrigeration warehouses and ice rinks because of the temperatures it can endure.

Safe PEX Tube Temperature FAQ

Is PEX pipe OK for hot water?

PEX pipe is made to withstand both hot and cold temperatures of water within a standard range. No pipe is made to withstand extreme cold or extreme hot, including PEX.

PEX pipe can be used for residential and commercial water lines in both hot and cold temperatures. It will not melt and will stay resistant to heat up to temperatures of 200 degrees F.

How long does PEX pipe last?

PEX is very durable pipe and will last for many decades under normal conditions. Unless the pipe is damaged by weather or some other interference, PEX pipe should last for about 50 years before it needs to be replaced.

What is the drawback of PEX pipe?

PEX is a popular choice for plumbing because of the way it expands. The flexibility of the pipe gives it high tolerance to freezing and other damage that commonly causes leaks in pipes.

However, PEX pipe does have some disadvantages. UV light will cause PEX to crack and break, so this pipe is not suitable for use outside unless it's buried or otherwise covered.

PEX also is very different from other types of pipe, which means it requires special tools to cut and to join pieces of it together. PEX is also made with material that is not environmentally friendly, which means it's not easy to dispose of and it's actually illegal to use in some places.

What is the difference between blue and red PEX pipe?

PEX pipe is sold in a variety of colors, but these o[tions are not made for looks. Red PEX is used for hot water lines and blue is used for cold water lines.

White or gray PEX can be used for either hot or cold.

Why is PEX banned in California?

PEX pipe was banned in California before 2010 but since then, there have been conflicting arguments for and against PEX. The pipe is banned statewide because the plastic material used to make PEX could add chemicals to drinking water as it passes through the pipes.

However, local jurisdictions inside California can choose to allow PEX pipe so PEX is not illegal everywhere in California.