Hayward Summit Heat Pump HP Error

[thadius65]

My heat pump is currently throwing an HP error and as I wait for authorized repair to check, I am trying to troubleshoot. Here is my setup:

Bottom Drain (2")
Skimmer A (2")
Skimmer B (2")

Return A (1.5")
Return B (1.5")

I have a Hayward 1HP dual speed super pump and a 244T sand filter. When on high, my pressure at filter reads 21psi, which is where it stays when things are running clean.

If I have drain and both skimmers open and attempt to start the heat pump, it will start and once compression kicks on, stop and throw the HP error. If I valve all off but one of the skimmers, heat pump works fine. Another test was to open all valves for drain/skimmers, but have the multiport valve on circulate. In this setup, the heat pump works fine, no error. During all these setups, the pressure remains the same at 21psi.

I have no visible leaks (no air bubbles in pump basket area. Any recommendations of other things to try prior to repairman getting here. It may just be a faulty switch on heat pump, but want to make sure I am not missing anything. I guess my biggest gripe is that I really want the bottom drains circulating while heating to get the cool water off the bottom of the pool.

Thoughts?

Thanks!

Ted

 

[Poolsean]

Make sure there's no debris around the evaporator coil (radiator looking perimeter of the heat pump). Make sure you have sufficient flow to the heat pump. You can check the inlet and outlet of the heat pump with it working properly, then with your main drains opened. You should see 1-5 degrees difference in the water temperature (check at your skimmer and at the closest return line). If you get more than that, it usually means you have lower than normal flow and are not cooling off the freon quick enough.
Also, if you check the air tempeture difference, it should be about 7-10 degrees colder (checking the air temperature away from the heat pump, then directly over the fan discharge air flow).
Again, make sure you have free flow of air to the unit, and sufficient water flow through the unit.