Expansion vessel in a heat pump system: proper operation and essential checks

The expansion vessel absorbs the change in water volume as the system temperature changes.

Why it is necessary

Without a sufficient vessel, the pressure can rise excessively when the water heats up.

Pre-charge

The pre-charge pressure must be compatible with the static height and the filling pressure of the system.

Symptoms of a problem

Large pressure fluctuations or frequent activation of the safety valve may indicate a problem with the vessel.

Check

The condition of the membrane and the pre-charge are checked periodically according to the manufacturer's instructions.