Worcester Bosch Short cycling due to control settings

Thermostat shows correct temperature but boiler cycles on and off very frequently.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Too tight temperature hysteresis, Incorrect boiler modulation settings, Oversized boiler, Minimum run‑time not configured

Safety first: Boiler parameter changes should be made by a competent person following the manual.

Adjust hysteresis: In thermostat installer settings, increase the temperature differential (e.g. from 0.2°C to 0.5°C) to reduce cycling.
Minimum on/off times: Set appropriate minimum run and off times if available.
Boiler settings: Ask a heating engineer to check boiler modulation and pump overrun settings to better match the property.

Medium 3/5