FAQs: Frequently Asked Questions
Do I need a water heater expansion tank?
Heated water expands. Without an expansion tank, the water heater pressure relief valve can open, spilling water onto the floor or down the drain. It is water you paid to heat.
The pressure relief valve on the water tank is an emergency control and is not intended to operate on a regular basis. If it fails, a system pressure can build to dangerous levels. Elevated system pressure can damage your water heater, cause fittings to leak, toilets to run and faucets to drip.
Installing a heater expansion tank will allow for thermal expansion of the water and will control the pressure it generates and keep it within a normal, safe operating range; well below the emergency setting of an emergency relief valve.