Water Heaters and Thermal Expansion: Does Your Water Heater Need a Thermal Expansion Tank?
Water Heaters: Friend or Foe?
Your Water Heater is one of the most expensive and important parts of your plumbing system. Without your water heater life just wouldn't be the same. Imagine cold showers every day! But did you know that your water heater could be causing a problem in your pipes?
Hot Water Expands
Hot water heaters do their job by using either an electric heating element or a gas burner to heat cold water and make it hot. The problem is that water expands when it is heated. This is called "Thermal Expansion".
A 40 Gallon Water Heater Can Cause An Extra Half Gallon
Due to Thermal Expansion, a regular 40 gallon hot water heater creates about an extra half gallon of water in the pipes while heating water from 70 degrees to 120 degrees. If the extra water doesn't have anywhere to go it causes the pressure in the pipes to go up, sometimes way up.
Water Heater Plus Closed System Equals A Problem
If you have a "Closed System", meaning there is a check valve or Backflow Preventer" on the incoming water line, the extra water volume caused by thermal expansion has nowhere to go. This means that the pressure in your pipes can get too high, possibly causing problems.
Too Much Pressure Is Bad
If your pressure gets too high because of thermal expansion it can cause several problems. One of the main issues is that your T and P Relief Valve on the water heater can start to drip or run. This valve is designed to release pressure if it gets up to 150 psi. The problem is that it's really a safety valve and isn't designed to open and close a lot. Too much could cause it to fail.
Thermal Expansion Can Cause Running Toilets
Another symptom of thermal expansion problems is a toilet that keeps running or kicking on from time to time. This is caused by the excess pressure overcoming the float on the fill valve, allowing water to run into the tank. Over time this can cause the fill valve to stop working and make it run constantly.
A Thermal Expansion Tank At The Water Heater Will Solve These Problems
If you are experiencing either of these problems, or if you are just replacing your water heater, it is a good idea to install a Thermal Expansion Tank. This is a small tank with an air bladder inside that is installed in the cold water pipe near the water heater. When the water heater comes on and starts heating, the extra water that is created is forced into the tank and compresses the air bladder. As the water cools, or a faucet is opened, the bladder pushes the extra water back out of the tank,
A Fairly Simple Job
Installing a Thermal Expansion Tank at your water heater is a fairly simple job. You just need to turn the main water off, install a tee and female adapter in the cold water pipe near the water heater and then screw the Expansion Tank into the adapter. A few basic tools and a little knowledge and you can eliminate thermal expansion from your piping system.
Your Water Heater is one of the most expensive and important parts of your plumbing system. Without your water heater life just wouldn't be the same. Imagine cold showers every day! But did you know that your water heater could be causing a problem in your pipes?
Hot Water Expands
Hot water heaters do their job by using either an electric heating element or a gas burner to heat cold water and make it hot. The problem is that water expands when it is heated. This is called "Thermal Expansion".
A 40 Gallon Water Heater Can Cause An Extra Half Gallon
Due to Thermal Expansion, a regular 40 gallon hot water heater creates about an extra half gallon of water in the pipes while heating water from 70 degrees to 120 degrees. If the extra water doesn't have anywhere to go it causes the pressure in the pipes to go up, sometimes way up.
Water Heater Plus Closed System Equals A Problem
If you have a "Closed System", meaning there is a check valve or Backflow Preventer" on the incoming water line, the extra water volume caused by thermal expansion has nowhere to go. This means that the pressure in your pipes can get too high, possibly causing problems.
Too Much Pressure Is Bad
If your pressure gets too high because of thermal expansion it can cause several problems. One of the main issues is that your T and P Relief Valve on the water heater can start to drip or run. This valve is designed to release pressure if it gets up to 150 psi. The problem is that it's really a safety valve and isn't designed to open and close a lot. Too much could cause it to fail.
Thermal Expansion Can Cause Running Toilets
Another symptom of thermal expansion problems is a toilet that keeps running or kicking on from time to time. This is caused by the excess pressure overcoming the float on the fill valve, allowing water to run into the tank. Over time this can cause the fill valve to stop working and make it run constantly.
A Thermal Expansion Tank At The Water Heater Will Solve These Problems
If you are experiencing either of these problems, or if you are just replacing your water heater, it is a good idea to install a Thermal Expansion Tank. This is a small tank with an air bladder inside that is installed in the cold water pipe near the water heater. When the water heater comes on and starts heating, the extra water that is created is forced into the tank and compresses the air bladder. As the water cools, or a faucet is opened, the bladder pushes the extra water back out of the tank,
A Fairly Simple Job
Installing a Thermal Expansion Tank at your water heater is a fairly simple job. You just need to turn the main water off, install a tee and female adapter in the cold water pipe near the water heater and then screw the Expansion Tank into the adapter. A few basic tools and a little knowledge and you can eliminate thermal expansion from your piping system.
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