Brand new Pentair Heat Pump

OP
OP
Yeshelloo
Mar 13, 2019
18
Safety Harbor, Fl
#21
The heat pump is a reverse AC unit. Have you had the pressures and refrigerant levels checked?

I would remove the side panels if you can and then can better listen and identify which internal component the knock is coming from. It should be more obvious if it is coming from the water pressure control valve or the compressor.
Yeah, refrigerant levels are all good. The banging is coming the area circled in red in the picture attached. I'm wondering if it's just the water bypass check valve banging open and closing.
 

Attachments

OP
OP
Yeshelloo
Mar 13, 2019
18
Safety Harbor, Fl
#22
There is a check valve on the pvc line coming out of the heat pump with a clear lid. Look in the clear part to see if the flapper is banging. Is the check valve pointing in the right direction?
Check valve flap after the heat pump stays open and is facing the correct direction. The noise is definitely coming from inside the heat pump. Attached a picture of the inside with the area circled where I'm getting the noise.
 

JamesW

TFP Expert
Mar 2, 2011
13,068
#23
I suspect that it's probably the check valve right there by the red box you drew.

The check valve says "Flow" on it.

The check valve is available but probably not replaceable because it's glued in.

R172305 Water Bypass Check Valve

You can get the manifold bypass kit.

475176Z Manifold Bypass Kit.

If you're getting air in the system, that can cause the check valve to bang. It's a strong 12 lb spring, so water would open the flapper and a big bubble of air would allow the flapper to slam shut.
 
Last edited:
OP
OP
Yeshelloo
Mar 13, 2019
18
Safety Harbor, Fl
#24
I suspect that it's probably the check valve right there by the red box you drew.

The check valve says "Flow" on it.

The check valve is available but probably not replaceable because it's glued in.

R172305 Water Bypass Check Valve

You can get the manifold bypass kit.

475176Z Manifold Bypass Kit.

If you're getting air in the system, that can cause the check valve to bang. It's a strong 12 lb spring, so water would open the flapper and a big bubble of air would allow the flapper to slam shut.
I'm not getting any air in the system, no bubbles coming out of the pool jets. I'm wondering if the pressure from my current pump is what's causing the check valve to open and then bang shut because it really seems like it's quite high for a pool. Plus, at the cost of the manifold bypass kit and check valve, I'm halfway to the cost of a variable speed pool pump so I'm figuring I might as well try replacing the pump before I buy those two parts.

This is probably a stupid question, but regarding the manifold bypass kit, it just looks like a standard PVC wye, what is so special about this piece that it costs $325 to replace?
 

JamesW

TFP Expert
Mar 2, 2011
13,068
#25
The flow shouldn't be high enough to cause any problems.

The manifold bypass kit is nothing special. The price is just what they think they can get away with.

Maybe just eliminate the internal bypass and install an external bypass.

Maybe there is something in the plumbing that is causing a blockage in the heater?
 
OP
OP
Yeshelloo
Mar 13, 2019
18
Safety Harbor, Fl
#26
The flow shouldn't be high enough to cause any problems.

The manifold bypass kit is nothing special. The price is just what they think they can get away with.

Maybe just eliminate the internal bypass and install an external bypass.

Maybe there is something in the plumbing that is causing a blockage in the heater?
So just to clarify, what you’re saying I should do it remove the wye bypass manifold valve and the check valve with the flow sticker on it. Where the water enters the system, tie together the inlet line with the part that coils and goes through the refrigerant and then tie the end part of that system to the outlet line. Pretty much just make it a closed system and then add a valve outside the system to control the flow of water actually going through the heat pump. Hope that makes sense.
 

JamesW

TFP Expert
Mar 2, 2011
13,068
#27
That's probably what I would do. It's just replumbing to eliminate the internal bypass.

As long as you control the flow to the heat pump, it should work the same.

I won't recommend it because you're modifying the heat pump outside its design.

You will have to decide what to do based on your own assessment.
 

JamesW

TFP Expert
Mar 2, 2011
13,068
#29
Maybe try flushing out the heater by putting some water through it in reverse to see if anything comes out.

At this point, we don't know why it's knocking or if removing the internal bypass would do anything.
 
OP
OP
Yeshelloo
Mar 13, 2019
18
Safety Harbor, Fl
#30
Maybe try flushing out the heater by putting some water through it in reverse to see if anything comes out.

At this point, we don't know why it's knocking or if removing the internal bypass would do anything.
Ya know, I went on a walk and I literally thought to myself this same thing. So this weekend I'm going to disconnect everything and see if I can flush it in reverse.