water heater

Replace with a brass swing check valve.

The check valve on WH is plastic plunger/spring & O-ring. It is inside the nipple on WH tank.

Old-Biscuit wrote:
Sounds like the 'instant hot' was back-feeding into WH which caused the PRV to operate.....opened and allowed the 'hot' water/steam to vent

Either you don't have a check valve on WH tank hot out or if you have one it is stuck open.

After i gave it some time to cool down it seemed to operate normal again.Almost as if it corrected itself.If the chck valve is stuck open how do i correct it?

Sounds like the 'instant hot' was back-feeding into WH which caused the PRV to operate.....opened and allowed the 'hot' water/steam to vent

Either you don't have a check valve on WH tank hot out or if you have one it is stuck open.

westend wrote:
Your instant heater make be stuck in the "on" position. Find the circuit breaker that controls it and switch that breaker "off".

It seems the instant hot water device on the sink caused the hot water heater to pour water out of it.The smoke was actually steam from the hot water coming out of the hot water heater outside.I waited for about an hour to let it cool down and turned the pump on to fill it back up and the pump shut off.So that told me it wasnt leaking anymore.So i fired up the hot water heater and no leak and the hot water is working.Do you have any idea what could have happened?

Your instant heater make be stuck in the "on" position. Find the circuit breaker that controls it and switch that breaker "off".