Is a thermal expansion tank necessary for your home water heater? On the outside, it may just look like a smaller accessory to your main hot water tank, but it is specifically designed for the safety and health of your system by offloading excess water pressure from your hot water tank.

This appliance is named thermal expansion tank because of its function of accommodating thermal expansion in your hot water heater. With a little understanding of how your water heater functions, you can develop good habits to make this essential appliance work more effectively and last longer.

Thermal Expansion and Your Hot Water Heater

If you’ve ever had a pot boil over, you might understand the complications of thermal expansion. As the water heats up and gets closer to a boiling point it responds by expanding. In the case of your kitchen pot, this means a mess on your stove, but in the case of hot water heaters, the effects can be much more dramatic and dangerous.

A functional thermal expansion tank is made specifically to relieve pressure from your main water heater as the temperature rises inside the main tank. Forty gallons of water will expand to almost 42 gallons once heated, and your thermal expansion tank is built to handle the excess and prevent damage to your hot water heater.

System Safety and Risks of Thermal Expansion

It is in the best interests of any homeowner to make sure their hot water heater and all of its components, including the thermal expansion tank, are routinely inspected and up to code. The reason local laws require a thermal expansion tank is that without one a water heater cannot be considered safe. In addition, rapid thermal expansion inside your hot water heater can lead to a total system failure that will require repair or a new hot water system.

In addition, the results of a faulty thermal expansion tank may cause water damage to the surrounding property or your home. Water in the wrong places is usually a recipe for disaster in any home, and in some cases, this will point directly to an issue with your thermal expansion tank.

Signs of Thermal Expansion Tank Failure

If you’re wondering if your thermal expansion tank is working correctly, there are a few early indicators that there may be a problem. It’s important to keep in mind that not all issues your thermal expansion tank can experience will be evident from what you can see or feel. Only a qualified specialist will be able to determine the health of your thermal expansion tank and your hot water heater.

Feel for Condensation

An early sign that your expansion tank may need service is apparent condensation on the outside of the unit. This condensation can indicate a blockage and can eventually lead to rusting, or damage to nearby electronics or flooring. If you can feel or see excess condensation you should act fast to schedule an inspection.

Check the Temperature

Another sign is a change in temperature on the thermal expansion tank. A functioning expansion tank should have cool compressed air at the top of the tank and will be warmer on the bottom. If you touch the top and bottom of the tank and they feel about the same temperature this indicates the tank is not functioning properly.

Look at the Pressure Reduction Valve (PRV)

Located elsewhere in your hot water system is a pressure reduction valve. This valve relieves pressure from the water heater and thermal expansion tank when it reaches critical levels. If this valve is frequently dripping it means that your system is frequently not able to handle the water pressure it is producing.

These are common strategies to help you keep your hot water heater healthy between inspections but are not replacements for expert assessment of your thermal expansion tank. What is asked of our hot water tanks every day is considerable, and the key is to stay proactive and address any problems before they grow into larger ones.

Get Professional Hot Water Heater Inspections

As with any household appliance, your hot water heater and thermal expansion tank require regular inspection and maintenance long before these symptoms become apparent. Just because issues with your thermal expansion tank may not always immediately impact the pressure or temperature of your hot water does not mean there isn’t an issue present that may eventually lead to system failure. A licensed specialist can help you ensure your hot water heater’s health and longevity and can help postpone the need for a new hot water heater

If you can’t remember the last time you’ve had your hot water heater inspected, or you identify any common symptoms of thermal expansion tank failure reach out to schedule an appointment with a professional today!