Heater frequently stops with no code when pump speed is reduced (variable-speed pump)

Safety first: Adjust pump settings according to manufacturer instructions.

• Increase pump speed: Program a higher minimum RPM for the heating schedule so that the BWT flow switch remains closed.
• Clean filter: Ensure the filter is clean to maximize flow at lower speeds.
• Adjust bypass: If a bypass is installed, partially close it to force more flow through the heater while maintaining safe system pressure.

If the heater still drops out at low speeds, consult BWT documentation for minimum required flow and adjust pump programming accordingly.