My main circulation pump failed a few days ago and while waiting for repair I noted that my hot tub drained. From various sites on the web I understand that this is normally indicative of a failed check valve which is allowing water from the hot tub to drain back to the pool.
My question is regarding how I might identify the particular valve that has failed. I've attached a picture of my pool return configuration. Essentially what I see is that water flows from the heater through a check valve and into a diverter valve that has outputs to both the pool and spa. There is, on the spa return line, a connection with a second check valve that goes into the ground. I can't for the life of me figure what this is for but I'm thinking that this check valve may be the one that has failed.
However it appears that there is a separate jet pump that provides water to the water feature (waterfall over side of spa) that also has a check valve on the discharge side (see the attached pic). I don't know where the suction for this pump is but assuming that it comes from the pool failure of this check valve could also result in drainage from the hot tub to the pool.
Is there a way to figure out which of these two check valves is the one that has failed?
Also, when replacing the check valve do I need to close any valves to isolate the system or is it sufficient to simply have the pump turned off?


My question is regarding how I might identify the particular valve that has failed. I've attached a picture of my pool return configuration. Essentially what I see is that water flows from the heater through a check valve and into a diverter valve that has outputs to both the pool and spa. There is, on the spa return line, a connection with a second check valve that goes into the ground. I can't for the life of me figure what this is for but I'm thinking that this check valve may be the one that has failed.
However it appears that there is a separate jet pump that provides water to the water feature (waterfall over side of spa) that also has a check valve on the discharge side (see the attached pic). I don't know where the suction for this pump is but assuming that it comes from the pool failure of this check valve could also result in drainage from the hot tub to the pool.
Is there a way to figure out which of these two check valves is the one that has failed?
Also, when replacing the check valve do I need to close any valves to isolate the system or is it sufficient to simply have the pump turned off?

