Completely confused over solar panel plumbing with heat pump

mmusone

New member
Jul 11, 2019
2
Buffalo, ny
Hi All,

I've been having years of problems with my pool...and i've been going through the existing plumbing versus what the pentair manual says..and it looks completely backwards and just plain jacked up! It looks so backwards that i'm posting to see if i'm missing anything..

What all the diagrams I see online, the piping is supposed to go from the filter to the 3-way valve, which directs it either to the solar panel or directly to the pool heater. If going to the solar panel, it still goes to the pool heater INLET.

Mine however seems to Tee BEFORE the heater, so even if the solar panel is on, some water still goes to the heater. Additionally, the solar panels return AFTER the heater at another Tee, i.e. at the heater OUTLET. it almost seems like in either case, there's constant back pressure..either the solar panel water trying to go in the OUTLET of the pool heater..or the water BEFORE the heater trying to push up past the solar panel check valve..

it just seems completely backwards. This is also a property that I rent out as a vacation rental..and it seems as though with all the valves, that I can probably manually set them to operate in heater-only or solar-only..but nothing on an automated basis for tenants..

Should the best solution be to simply re-plumb to the standard "correct" way, or am I missing something?

The photo is my actual plumbing, and the diagram is what I pulled up on the internet.
I can make a diagram of my actual setup if it would be helpful.

Thanks for any help,
Mark

UPDATE: I added a diagram I just drew of the existing plumbing...
 

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Last edited:
I am actually surprised that your setup actually works very well. Most of the water is going to bypass solar through the heater the way it is setup now so efficiency is going to suffer. Mine is setup like this:

1640632330805.jpeg
 
Welcome to TFP.

Your HP creates a greater restriction in the floe ("head") then a gas heater. I suspect that is why your solar output is setup to bypass the HP. It gives a greater flow rate bypassing the HP.

The manual valve on the HP input looks like it should turn off the water into the HP when you want to run the solar and open the valve into the HP when you want to run the HP.

Depending what HP and automation you have you may be able to put an actuator on the HP manual valve and have the automation open the valve when the HP is turned on.
 
That’s a dangerous setup as well since the pressure switch in the HP can still be activated even when no water is flowing through it (back pressure from the solar return line on the HP output). If someone inadvertently turned on the heat pump with the valves not correctly set, it could run with no flow. That’s very bad for the heater.

I would redo the plumbing so that the heaters are in series and each has bypass plumbing and valves associated with it.

The only way to automate the system would be if you have a decent automation controller that can run multiple heat sources. The Pentair EasyTouch OR IntelliCenter could do that. I’m sure Hayward and Jandy have equivalent controllers. You’d also need actuators on each heat source 3 way valves.
 
That’s a dangerous setup as well since the pressure switch in the HP can still be activated even when no water is flowing through it (back pressure from the solar return line on the HP output). If someone inadvertently turned on the heat pump with the valves not correctly set, it could run with no flow. That’s very bad for the heater.

I would redo the plumbing so that the heaters are in series and each has bypass plumbing and valves associated with it.

The only way to automate the system would be if you have a decent automation controller that can run multiple heat sources. The Pentair EasyTouch OR IntelliCenter could do that. I’m sure Hayward and Jandy have equivalent controllers. You’d also need actuators on each heat source 3 way valves.
So, the interesting thing about what you just said..is this all started because my heat pump CONSTANTLY shows a "FL3" code (every day), which means it has to be manually reset, versus the normal "FL0"..indicating a flapping of the pressure switch 3 times over a single hour. It's this problem I've been trying to figure out that made me realize the plumbing is all wrong...and possibly by re-plumbing correctly, it'll fix the problem.

Thanks again,
Mark
 
I would guess your HP was the last thing added and where it Ts off to the HP originally there was 90s. The return of the solar should go into HP inlet or HP bypass and return to pool. Automation would give you more control as stated above.
 
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