Mechanic,
Did you ever confirm if the circulator moving water through the desuperheater coil is moving water? If not, here is an idea to try that doesn't require cutting into your lines. I saw you reference the pex lines, so I'm assuming that the circulator plumbing somewhere is a pex line that you can "squeeze" thereby causing a restriction.
Assuming that the pump is working properly and is indeed moving water, if you monitor the amps driving your pump, you should see it go down when you constrict that pex line. When you stop water from flowing with your pinch point the amount of work being performed by the pump should go down, hence the amps will be lower. If you pinch/unpinch and you don't see your circulator pumps amp change whatsoever, that would be a good indicator that there is another restriction somewhere and the pump isn't doing anything to start with. A simple clamp on meter and a pair of vice grips with some duct tape to protect the pex line from the jaws is all you would need.
I agree with the others and I believe that in cooling mode your desuperheater should work well. The symptoms you described earlier are consistent with either the pump not on or it is on, yet a restriction is not allowing the water to flow in that circuit.
Len
|