The way that it works is this.
Water heater thermal expansion tank leaking.
If the extra volume has nowhere to go it pushes on the walls of your plumbing.
You see as water is heated it expands.
This prevents a water heater from exploding or turning into a missile.
Go to the expansion tank and connect the pump outlet to the schrader valve.
Turn on the tap drain all the pressure from the system.
When this happens excess water is immediately sent to the expansion tank to lower pressure levels inside the water heater.
Just replace the valve.
Finally if none of the prior inspections showed a cause for leaking then it is likely that the tank inside the water heater has gone bad.
This tank sits off to the side of your water heater and is designed to catch any excess water from the water heater tank.
Close the water to your home with the main shut off valve.
The risk of pressure damage from thermal expansion is seldom a concern for tankless water heaters but if you own a tank style heater your plumbing system may be at risk.
Even in the best boiler system your expansion tank may begin to experience some leaks.
You can think of this process as bending a paper clip.
The changes in pressure inside the expansion tank can bring about the degradation of the water heating system and cause leaks you will need the following tools to fix and repair you.
With enough bending the paper clip will break.
The expansion tank is a pressurized system.
A water heater expansion tank also called a thermal expansion tank is a safety device designed to protect your household plumbing from thermal expansion.
An expansion tank is a small tank that protects closed and domestic water heating systems from excessive pressure.
If your water heater holds 50 gallons of cold water it will expand to about 52 gallons when it is heated.
But sometimes due to wear and tear your expansion tank may start leaking.
If the tank has ruptured and is leaking the water heater cannot be fixed and it must be replaced.
When a tprv at a water heater leaks it s usually a simple fix.
Hang the meter on the tap to determine the water pressure in the current system.
Normally this will be a major flooding leak not small dripping.
When water is heated or the hot water is shut off quickly the tanks filled with both air and water will equalize the resulting water pressure.
Step 1 investigate to find source of leak.