What pipe should not be used for hot water?

Author: Bettye Schoen IV  |  Last update: Monday, January 5, 2026

Most newer homes use PVC piping which costs less but is not reliable at high temperatures. If the water temperature is over 140 degrees, PVC pipes and fittings start to degrade. This makes it less than a stellar choice for hot water heaters.

Which pipe is not recommended for hot water?

Susceptibility to warping: PVC is not equipped to transport hot water because, like other thermoplastics, PVC can warp and melt when in contact with heat. Size: There are a few sizing options for PVC pipes, which can be an issue if you have specific size requirements.

Is it OK to use PVC pipe for hot water?

PVC is not suitable for hot water supply lines because of temperature limitations - CPVC is suitable for all supply lines but it requires the same amount of fittings and joints as hard copper. The joints are solvent welded (``glued''); no heat is involved, so fire risks are eliminated.

What type of pipe is best for hot water?

CPVC pipes are an ideal choice for hot water plumbing. They are made after adding material that goes through extra chlorination process which gives CPVC higher quality.

Is PEX pipe safe for hot water?

PEX pipe is approved for residential and commercial hot and cold water distribution systems, municipal water service lines, radiant panel heating systems, hydronic baseboard heating systems, snow and ice melting systems and building services pipe. Can PEX save me money? Yes, PEX pipe can save money in numerous ways.

What Pipes Are Suitable For Hot Water Plumbing?

How hot is too hot for a PEX pipe?

PEX tubing can be used up to 200° Fahrenheit for heating applications. For plumbing, PEX is limited to 180° F at 100 psi. Temperature limitations are always noted on the print line of the PEX tubing.

Where should you not use PEX?

PEX pipe can be used as a service line based on its corrosion resistance to soil and water, its long life and its oxidative resistance. Our PEX pipe is not suitable for use in areas where the soil is or may become contaminated, including soil used for backfilling.

Which pipe material is not a good conductor of hot water?

When contrasted with metal pipes, CPVC exhibits poor thermal conductivity. Less condensation on cold water pipe materials and less heat loss from hot water improve insulation and decrease energy loss.

Is PEX better than CPVC for hot water?

CPVC pipe can withstand higher temperatures than PVC or PEX pipe (up to 200 degrees Fahrenheit vs. 140 degrees Fahrenheit).

What PVC pipe is rated for hot water?

As mentioned before, CPVC is more suitable for hot water applications up to 200F. PVC is still often used for unheated water as well as for vent and drainage systems; however, CPVC has become widely used for both hot and cold potable water.

Why is CPVC not used anymore?

Fragility and Brittleness. ASTM F441 CPVC pipes can become brittle over time, particularly under stress or extreme temperatures. This brittleness makes them more prone to cracking and failure. In colder climates, this issue is exacerbated as pipes can freeze and break easily.

Will hot water crack PVC pipe?

It is okay to pour boiling water down the sink if your plumbing is clear. However, a blockage can trap the water in the pipe. This can melt PVC pipes and seals, causing serious damage. Additionally, using boiling water to unclog a toilet can melt the wax seal around the toilet.

Which plastic pipe for hot water?

PEX piping is the most commonly used plastic pipe in the UK. A multilayer high-density polyethylene pipe. Durable and flexible and can bend 90-degrees. PEX pipe ideal for both domestic and commercial hot and cold water installations.

Why can't you use PVC for hot water?

While PVC is excellent for water service lines and DWV applications, it's not recommended for hot-water distribution systems because it can only withstand temperatures up to 140℉. CPVC and PEX, however, can withstand temperatures up to 200℉.

What is the best material for hot water lines?

PEX is cross-linked polyethylene, a flexible plastic option for hot and cold water residential pipes. This lightweight material makes a flexible pipe that can easily run through the twists and turns of a residential plumbing system. It's suitable for cold and hot water and has few connections between the pipes.

What are the disadvantages of CPVC pipes?

Although being a plastic it doesn't support combustion as it requires 60 % of oxygen to burn. Additionally, CPVC also has low thermal conductivity, ensuring reduced heat loss. Cons: Some of CPVC's drawbacks include being more expensive than PVC and potential to become brittle over time.

What is the best plumbing pipe for hot water?

PEX Pipe. PEX, a cross-linked polyethylene pipe, is considered by some to be the greatest innovation for DIY plumbers. PEX pipes often replace copper for hot and cold water in residential retrofits. They are easy to cut, install and connect and less costly than copper.

Is there a lawsuit against PEX pipe?

PEX Pipe Class Action Lawsuits

A number of manufacturers, including Uponor, Viega, Nibco and Zurn, have already been sued over their PEX piping products.

What lasts longer PEX or PVC?

Longevity. In the right conditions, PVC pipes can last upwards of 70 years. Both ABS and PEX pipes have about 40-50 years of life.

What pipe should not be used for hot water systems?

If the water temperature is over 140 degrees, PVC pipes and fittings start to degrade. This makes it less than a stellar choice for hot water heaters.

What pipe can I use for hot water?

Copper pipes are used in hot and water applications in many places. This piping system is a common one both in underground and above the groundwater systems. The major advantage of copper pipes is making multiple connections by a plumber.

What are the worst heat conductors?

Plastic, Rubber and Asbestos are worst conductors of heat. because they don't have a proper structure in place. All these materials don't have a proper lattice structure.

Why do plumbers not like PEX?

Material Concerns: One of the primary concerns about Pex plumbing is the material itself. While Pex pipes are undoubtedly flexible, making them easier to install in tight spaces, they are not as durable as traditional materials like copper or even PVC.

Why is PEX banned in California?

Currently, PEX plumbing is one of the most widely used plumbing systems around the world. It was temporarily banned in California for a while due to concerns about toxic materials but this was later disproven by laboratory tests.

Do mice eat PEX pipe?

PEX Pipe Is Vulnerable

Rodents Chewing Through PEX Pipe is a common problem in our area. It doesn't matter how old your home is, if you have an attic, you need to watch for rodent damage to PEX Pipe or PVC. If you're hearing rustling noises coming from the attic, it's time to do an inspection.

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