Problem

The heat pump starts too often (short cycling)

Short cycling means the compressor repeatedly starts and stops within a short time. This wears the compressor and lowers efficiency, since every start is the least efficient part of a cycle.

How to recognise short cycling

If there are more than 10–12 compressor starts per day in moderate weather, or cycle length is under 10 minutes, that's a strong indicator of short cycling.

Common causes

Oversized unit capacity relative to the house's heat demand, too small a water volume in the system, closed thermostatic valves in most rooms, or too narrow a hysteresis.

What's safe to try

Open thermostatic valves in more rooms to increase active heating surface, and monitor the number of starts. Changing buffer volume or hysteresis is an installer's job — we don't recommend doing it yourself.

Frequently asked questions

Does short cycling damage the compressor?+

It may not cause an immediate fault, but frequent starts shorten lifespan and raise consumption.

Does a buffer tank solve the problem?+

Often helps if the cause is a small water volume. The need should be assessed by a specialist based on measurements.

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