Pool heater runs but pool water does not reach the set temperature or heats very slowly.

Safety first: Turn off power and pump before cleaning or adjusting hydraulic components.

• Clean evaporator coil: Remove debris and gently wash the coil with low‑pressure water. Do not bend fins.
• Check water flow: Verify that the pool pump is operating correctly and that valves are set to provide adequate flow through the Hewalex heater. Adjust bypass according to the installation manual.
• Inspect filter and baskets: Clean skimmer and pump baskets and backwash or clean the filter to restore design flow.
• Check setpoint and timers: Ensure the temperature setpoint is higher than current water temperature and that any timers allow sufficient run time.
• Call technician if needed: If performance remains poor, a technician should check refrigerant charge and inspect the titanium heat exchanger for scaling.