Solar heating only works when pump is in high-speed mode; in low-speed mode, solar never activates.

Safety first: Turn off power before adjusting wiring; programming changes can be done with power on per manual.

• Adjust pump programming: Set a dedicated higher-speed schedule or relay trigger for when solar is active to ensure adequate flow.
• Check flow switch: If equipped, verify that the flow switch is correctly oriented and not sticking. Replace if it requires excessive flow to close.
• Optimize plumbing: Ensure all solar valves are fully open and that there are no unnecessary restrictions in the solar loop.
• Consult installer: If plumbing runs are long or undersized, a professional may need to reconfigure piping or recommend a different pump speed strategy.