Solar pool heater makes a gulping sound the whole night even when turned off

[kp326470]

Hello there,


First of all I should say that I have learned a lot from these forums. So thank you so much for all these amazing discussions and suggestions.

We replaced our old solar pool heater panels with new ones. All the plumbing and valves setup is still the same. We have a relatively simple setup. First we have a Pentair pool filter and then a Jandy swing check valve. Then the pipe from the Jandy swing valve goes to the Pentair diverter valve. Left side pipe of the diverter valve goes to our Solar pool heater which is mounted on the second floor roof with a vacuum release valve. The solar return pipe has another Pentair swing check valve installed and after the check valve the pipe connects back to the pool return.

Since we started using our solar pool heater at the start of the summer, I hear this constant gulping sound intermittently all night even when the pump is turned off. Just for sake of it, I replaced the Pentair diverter valve's internal assembly and also installed a new Pentair check valve in the solar return line. But still this annoying gulping sound hasn't stopped. As the solar pool heater panels as well as the inlet and return pipes are next to our master bedroom this sound is a bit distracting.

Does anyone have any idea why the solar pool heater is making a gulping sound?

I have attached a photo of my system. I will appreciate your help and thanks in advance.

 

[ajw22]

Welcome to TFP.

Just for sake of it, I replaced the Pentair diverter valve's internal assembly

Did you use a solar diverter valve?

Only Compool, now Pentair makes proper Solar Diverter Valves.

• 263047 - 3-Way Solar Valve with Drain-Down, CPVC 2 in. (2½ in. slip outside)
• 263057 - 3-Way Solar Valve with Drain-Down, CPVC 2½ in. (3 in. slip outside)

These valves are included in the Pentair Solar Touch and Sun Touch control systems.

Installers will use other model standard 3-way diverter valves and drill a 1/4" hole in the center of the diverter.

A Solar Diverter Valve is different then a standard 3-way diverter valve. A Solar Diverter Valve has a drain hole that allows the solar panels to drain down from the supply side of the panels, which can be important (depending on how your system is configured) when the valve is closed. The "hole" is actually a small check valve in the diverter

 

[MSchutzer]

The Jandy check valve that follows your filter needs its flapper replaced. The Pentair one in the solar return line isn’t causing the problem.

When the system shuts off at the end of the day the filter is full of water that is trying to drain back into the pool by flowing back through the pump. This is prevented by the Jandy check valve that is just after the filter. That valve is slowly leaking when the system is off. As air leaks back through that valve (air because the solar vacuum breaker lets air into the system to drain the pipes) the water in the filter slowly drains back to pool via the pump intake line.

Just as with a water cooler you will hear the air gulping into the filter every so often as the water slowly leaks back to the pool.

I had the same problem with my solar system, and a leaky check valve is the cause, in this case it’s your Jandy one that’s just after your filter output.

 

[kp326470]

Welcome to TFP.



Did you use a solar diverter valve?

Only Compool, now Pentair makes proper Solar Diverter Valves.

• 263047 - 3-Way Solar Valve with Drain-Down, CPVC 2 in. (2½ in. slip outside)
• 263057 - 3-Way Solar Valve with Drain-Down, CPVC 2½ in. (3 in. slip outside)

These valves are included in the Pentair Solar Touch and Sun Touch control systems.

Installers will use other model standard 3-way diverter valves and drill a 1/4" hole in the center of the diverter.

A Solar Diverter Valve is different then a standard 3-way diverter valve. A Solar Diverter Valve has a drain hole that allows the solar panels to drain down from the supply side of the panels, which can be important (depending on how your system is configured) when the valve is closed. The "hole" is actually a small check valve in the diverter

Hello Allen,
Yes I have installed the diverter that has solar drain back. But thanks for pointing that out.

 

[kp326470]

The Jandy check valve that follows your filter needs its flapper replaced. The Pentair one in the solar return line isn’t causing the problem.

When the system shuts off at the end of the day the filter is full of water that is trying to drain back into the pool by flowing back through the pump. This is prevented by the Jandy check valve that is just after the filter. That valve is slowly leaking when the system is off. As air leaks back through that valve (air because the solar vacuum breaker lets air into the system to drain the pipes) the water in the filter slowly drains back to pool via the pump intake line.

Just as with a water cooler you will hear the air gulping into the filter every so often as the water slowly leaks back to the pool.

I had the same problem with my solar system, and a leaky check valve is the cause, in this case it’s your Jandy one that’s just after your filter output.

Hello Mark,

I think you are right that perhaps my flapper on the Jandy check valve might have a leak and hence burping that air out through my solar feed pipe. I will replace the flapper and see if that resolves the issue. Thank you for your suggestion.

 

[kp326470]

Hello All,

So now I am facing another issue with the Pentair Solar Diverter valve. As I mentioned earlier I completely changed the internal assembly of the diverter valve and installed a new Pentair check valve on the return. Now when I shut off the solar by turning the diverter valve to off position pointing to the solar side and basically diverting the water to the bypass. But still I hear some amount of water going to the solar panels.

Is there a possibility that the whole diverter valve housing itself is faulty?

I have seen online that some systems have an additional isolation valve (Pentair shut off valve/Ball Valve) after the diverter valve on the solar line. This generally is recommended to isolate the solar panels completely either for servicing or winterization. Indeed I am trying to shut off the system for winterization. What is your opinion on having this additional backup shut off valve to shut off the water to solar after diverter?

Thanks