My built-in spa appears to have two backflow prevention devices on the same return line. One is a check valve near the 3-way valves and the other is a plunger style port. See photos below. Anyone seen one of these plunger style ports before? I am having trouble finding them online.
On occasion, the plunger style port does not retract fully (as shown in the photo) when the pump turns off - just a slight touch will make it retract. If I leave it sticking out, the water level in the spa drops several inches to match the pool level (and I get DE powder in the pool). So that tells me the in-line check valve does not appear to be working either. Perhaps the prior owner added the plunger style valve instead of replacing the failed check valve.
When the plunger style port does retract, I still lose about 1 or 2 inches of water from the spa overnight. That was not the case in prior seasons so perhaps the gasket on the plunger style port is getting worn out.
Not sure why there are two devices - they seem redundant. Is it better to have two devices like these on the same return line?
On occasion, the plunger style port does not retract fully (as shown in the photo) when the pump turns off - just a slight touch will make it retract. If I leave it sticking out, the water level in the spa drops several inches to match the pool level (and I get DE powder in the pool). So that tells me the in-line check valve does not appear to be working either. Perhaps the prior owner added the plunger style valve instead of replacing the failed check valve.
When the plunger style port does retract, I still lose about 1 or 2 inches of water from the spa overnight. That was not the case in prior seasons so perhaps the gasket on the plunger style port is getting worn out.
Not sure why there are two devices - they seem redundant. Is it better to have two devices like these on the same return line?
