For "restoring the air pocket". The trailers water system only needs to be depressurized. The pump needs to be turned off, not disconnected. The city water supply needs to be shut off or water hose disconnected from the outside water supply (city water).
A) Then as it was suggested turn on an inside hot water faucet to bleed off the pressure. Then manually flip the aluminum lever on the water heater relief valve 90 degrees on the outside of the trailer inside the access door. Water will flow out of the relief valve. When it stops flip the lever on the relief valve to reset the lever. Close the hot water faucet you opened and then turn the pump back on or restore the city water supply. Then open a hot water faucet until it stops spitting air to restabilize the water level in the hot water heater.
or
B) Instead of using the relief valve to restore the air pocket, turn on an inside hot water faucet to bleed off the pressure. Then open the hot water low point drain for about a minute. This will also drain some water from the water heater without having to run outside to use the relief valve. Close the low point drain and hot water faucet. Then turn the pump back on or restore the city water supply. Then open a hot water faucet until it stops spitting air to restabilize the water level in the hot water heater.
If the relief valve keeps sweeping you may have debris (sand, calcium deposit, piece of Teflon tape, etc.) trapped under the relief valve seat. You may need to manually cycle the relief valve lever quickly a couple times to flush it out.
If the valve keeps leaking it may need to be replaced.
