Rooftop solar pool heater leaking even while turned off

[TonyAl]

I have a rooftop solar heater, not sure which brand. It was already here when I moved in a couple years ago. I noticed that during the past couple days there is water coming off my roof any time the pool pump is on. The heater is turned off, and the valve is closed. When I turn the pump off I can hear the vacuum breaker on the roof draining the panels. The filter pressure is at 10 psi with the solar heater off, it goes up to 16-17 with the heater on.

I am trying to figure out why the solar heater is being filled with water even when it is turned off. Any suggestions on where to start? Thanks

 

[ps0303]

Do you have a hand valve and a check valve on the solar?

 

[TonyAl]

Not sure what a hand valve is. The valve that opens to send water to the rooftop heater has a motor on it and is controlled by the heater temperature controller.
There is a check valve in the pipe coming down from the roof.

 

[Pool Clown]

When you say your heater is off, do you mean that it, the solar is turned off and has been winterized for the season? Or it is just turned off? And if it is winterized, did you call a company to come and do it?

 

[Isaac-1]

Many of those automatic valves have a pin hole drilled in them to allow the water to drain back with the pump is off, this has the side effect of filling up the solar panels slowly when the pump is running.

Ike