Pool heater question

xpert66

Active member
Apr 11, 2021
29
Central NJ
Pool Size
13500
Surface
Vinyl
Chlorine
Liquid Chlorine
I have a Hayward HeatPro Heat pump. I installed bypass valves per the manufacturer's direction. Duting the warm weather we had I did not run the heater and shut the valves off to bypass it. Should I have just left the valves open and have water run through the heater (with the heater off) or leave the bypass valves closed?
1. Would water harm the heater sitting in it while bypass valves are off?
2. Would water (with chemicals, ie. chlorine/shock, etc.) harm the heater if contiously flowing through the heater unnecessarily without the heater being used?
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
18,608
Tucson, AZ
Pool Size
16000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Heat pumps have terrible head loss so constantly running water through it when it’s not in use is only going to restrict the water flow throughout your system. A bypass is a good idea but it’s always advisable to open up the bypass every week to flush the heat exchanger. You could leave the bypass very slightly open so that there is always a trickle of water through the heater as another option. As long as you follow the TFP method of pool care and you don’t add chemicals into your skimmer, your heater will not be affected by the chemicals you use to maintain your pool.
 

xpert66

Active member
Apr 11, 2021
29
Central NJ
Pool Size
13500
Surface
Vinyl
Chlorine
Liquid Chlorine
Heat pumps have terrible head loss so constantly running water through it when it’s not in use is only going to restrict the water flow throughout your system. A bypass is a good idea but it’s always advisable to open up the bypass every week to flush the heat exchanger. You could leave the bypass very slightly open so that there is always a trickle of water through the heater as another option. As long as you follow the TFP method of pool care and you don’t add chemicals into your skimmer, your heater will not be affected by the chemicals you use to maintain your pool.
Thanks for the info. The bypass I installed will keep the water inside (see pic) unless I unscrew both inlet and outlet ports and move the heater a bit. Would I need to add valves at each inlet/outlet port before the bypass valves to drain the water while keeping pool functional? IMG_20210616_142856_01.jpg
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
18,608
Tucson, AZ
Pool Size
16000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
I looked at the manual online and it doesn't look like that Hayward Heatpump has a drain plug. So, in order to winterize it, you would need to undo the couplings and let the water drain out.

Also, I know that you followed the diagram in the manual, but that same bypass could have been achieved using one 3-way Jandy valve on the input side and a check valve on the output side. Those cheap ball valves are not reliable and the handles often degrade and fall apart within a few years. You could add valves to drain the heatpump but that would just be asking for a leak. Simply undo the couplings and allow the water to drain.
 
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xpert66

Active member
Apr 11, 2021
29
Central NJ
Pool Size
13500
Surface
Vinyl
Chlorine
Liquid Chlorine
I looked at the manual online and it doesn't look like that Hayward Heatpump has a drain plug. So, in order to winterize it, you would need to undo the couplings and let the water drain out.

Also, I know that you followed the diagram in the manual, but that same bypass could have been achieved using one 3-way Jandy valve on the input side and a check valve on the output side. Those cheap ball valves are not reliable and the handles often degrade and fall apart within a few years. You could add valves to drain the heatpump but that would just be asking for a leak. Simply undo the couplings and allow the water to drain.
Thanks Matt. I will be disconnecting the connections at the heater to drain properly to winterize. My question is during the season when I am not using the heater for extended periods of time. Is it ok to have water constantly running through it or if I bypass it will the water that remains in the heater affect it in any way?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
29,085
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
My question is during the season when I am not using the heater for extended periods of time. Is it ok to have water constantly running through it or if I bypass it will the water that remains in the heater affect it in any way?

Pool heaters are designed to be continuously in the water loop. Continuous water flowing will not wear out a heat pump.

Heat pumps create a lot of restriction in the water flow and you need to run a VS pump at higher RPM to get a desired GPM water flow. Thus some folks decide to bypass the heater when not in use do they can save electricity and run their VS pump at lower RPM.

Either way is fine. No one is better then the other. It’s your choice.
 

xpert66

Active member
Apr 11, 2021
29
Central NJ
Pool Size
13500
Surface
Vinyl
Chlorine
Liquid Chlorine
Pool heaters are designed to be continuously in the water loop. Continuous water flowing will not wear out a heat pump.

Heat pumps create a lot of restriction in the water flow and you need to run a VS pump at higher RPM to get a desired GPM water flow. Thus some folks decide to bypass the heater when not in use do they can save electricity and run their VS pump at lower RPM.

Either way is fine. No one is better then the other. It’s your choice.
OK just want to be sure water sitting in the heater while bypassing will not damage anything. I have a VS and run at 1900 RPM. That fine?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
29,085
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
OK just want to be sure water sitting in the heater while bypassing will not damage anything. I have a VS and run at 1900 RPM. That fine?

Yes, but I still don't understand why you are so fixated on bypassing your heater.
 

xpert66

Active member
Apr 11, 2021
29
Central NJ
Pool Size
13500
Surface
Vinyl
Chlorine
Liquid Chlorine
Yes, but I still don't understand why you are so fixated on bypassing your heater.
just want to make sure I do not damage this very expernsive heater. I was told that in the spring when adding more chemicals to start up the pool, that bypassing the heater is highly recommended.
 

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ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
29,085
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
just want to make sure I do not damage this very expernsive heater. I was told that in the spring when adding more chemicals to start up the pool, that bypassing the heater is highly recommended.
Told by who?

That type of bypass is fine for a while if the pH will be unstable and especially below 7.0. A bypass during spring startup is different then the questions you have been asking.
 
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