Did you ever get this resolved? I'm curious.
This is a plumbing mess. Yes, you should have a check valve to prevent back washing the filter into the pool when the pump shuts off. The heater should really be plumbed in after the solar in case you do want to run both simultaneously, however gas heaters do require a high flow rate, and poorly designed solar pool heaters can prevent that. I don't like the proximity of that 3 way valve to the pump outlet. The solar actuator appears to be on backward. If it turns 180 degrees the solar probably won't get enough flow. It should turn 90 degrees clockwise from the picture. There are other minor issues with the plumbing, too. Not very pro.
Anyway, a clogged filter sounds like a likely diagnosis of your issue. Otherwise it could be a failed flow sensor in the heater. It may just be coincidental with your solar install.
Sent from my SAMSUNG-SM-G900A using Tapatalk
This is a plumbing mess. Yes, you should have a check valve to prevent back washing the filter into the pool when the pump shuts off. The heater should really be plumbed in after the solar in case you do want to run both simultaneously, however gas heaters do require a high flow rate, and poorly designed solar pool heaters can prevent that. I don't like the proximity of that 3 way valve to the pump outlet. The solar actuator appears to be on backward. If it turns 180 degrees the solar probably won't get enough flow. It should turn 90 degrees clockwise from the picture. There are other minor issues with the plumbing, too. Not very pro.
Anyway, a clogged filter sounds like a likely diagnosis of your issue. Otherwise it could be a failed flow sensor in the heater. It may just be coincidental with your solar install.
Sent from my SAMSUNG-SM-G900A using Tapatalk