Opening Return Side - MPV position

[Cprtrails]

My pool equipment is above water level. If I need to open plumbing on the return/pressure side for a repair, couldn’t I set MPV to re-circulate to prevent water and DE from Draining out of the filter? On suction side I have a check valve between pump and MPV/filter and for extra measure a Jandy valve before pump I can close.

I had a slow leak at one of the heater connectors at glue joint last year and can’t remember which one. I’m going to replace both before I re-open for the season, but was just curious in case I need to open the return/pressure side during the season. Picture from when equipment was installed.

 

[Texas Splash]

couldn’t I set MPV to re-circulate to prevent water and DE from Draining out of the filter?

I was thinking CLOSED. Did you ever get this taken care of?

 

[1poolman1]

My pool equipment is above water level. If I need to open plumbing on the return/pressure side for a repair, couldn’t I set MPV to re-circulate to prevent water and DE from Draining out of the filter? On suction side I have a check valve between pump and MPV/filter and for extra measure a Jandy valve before pump I can close.

I had a slow leak at one of the heater connectors at glue joint last year and can’t remember which one. I’m going to replace both before I re-open for the season, but was just curious in case I need to open the return/pressure side during the season. Picture from when equipment was installed.

DE can only drain out backwards through the system. A check valve between the pump and MPV will prevent that from happening. The amount of water lost on the other side if the heater plumbing is opened is negligible.