PWM circulator control in a heat pump: what it is and how it works

Many modern circulators can be controlled with a PWM signal so that the heat pump can dynamically vary the water flow.

What is PWM

Pulse Width Modulation transmits a command by changing the duty cycle of an electrical signal.

Why it is used

The controller can increase or decrease the circulator speed depending on the required ΔT or flow.

Benefits

Electrical consumption is reduced and adaptation to load changes is improved.

Diagnosis

If the circulator does not follow the command, check the power supply, PWM signal, and actual water flow.