Inspect thermal expansion tank air precharge
Why it matters
A failed expansion tank bladder causes the relief valve to weep water, leading to water hammer, pressure spikes, premature water heater failure, and potential bursting. Replacement is $200–$400.
Stop forgetting to do this.
Hearth generates a personalized maintenance schedule so you never miss another inspect thermal expansion tank air precharge.
How to do it
- 1
Turn off the cold water supply to the water heater and depressurize by opening a hot tap.
- 2
Locate the expansion tank (typically mounted near the water heater).
- 3
Remove the rubber cap from the small air-precharge stem (Schrader valve) on tank end.
- 4
Connect a tire pressure gauge and read the air pressure.
- 5
If low, use a hand air pump to restore pressure to match your home's static water pressure.
- 6
Replace the rubber cap, restore water supply, and check for leaks at the tank.