Rheem heat pump installation doubles filter pressure

I recently had a new Rheem/Raypak model 6450PD installed to replacement my malfunctioning Hayward unit. Once the installation was completed the pool heater did a good job heating the pool however, I noticed that the pressure on my pool filter had more than doubled its normal operating pressure.

Since the heat pump is the only unit on the bypass I shut off the heat pump powered and ran a bypass test. With the heater completely bypassed, the filter pressure gauge reads 12 psi. With the bypass closed to return the water flow directly through the heat pump the pressure gauge reads 25 psi. I understand that the addition of a pool heater can increase the pool filter pressure by a few of pounds of pressure, but an increase of 13 psi seems to be a bit much.

After my installer talked with Raypak technical support they told him the heat pump should be run in a partially bypassed mode to bring the pressure down to 20 psi. Should I accept this as the proper solution to the pressure problem or should I have the Raypak replaced?

The max flow rate through that heat pump is 60 gpm. It’s possible that your pool pump is pushing more than 60 gpm, causing the back pressure to increase 13psi. It is common for pool owners to keep the bypass slightly open so that all of the water doesn’t flow through the heat pump.

My opinion is that another Raypak 6450PD would cause the same issue.

Thank you for your input InyoRob. Your second opinion was very helpful. I will keep the heat pump and run it partially bypassed.

1 Like