Ariston Short Cycling / Poor Boiler-Thermostat Matching

Thermostat shows large temperature swings and the boiler short-cycles (frequent on/off).

Safety Warning

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

Cycle rate set too high, Boiler minimum output too large for system, Thermostat located in small or rapidly heated room, No anti-cycling time configured

How to Fix / Troubleshooting

Safety: No mains work required.

Adjust cycle settings: Reduce cycles per hour or increase minimum on/off times in the thermostat installer menu.
Enable anti-cycling: If available, set a minimum off time between boiler starts.
Relocate thermostat: Move it to a larger, representative room that heats more slowly.
Boiler settings: Ask a technician to adjust boiler minimum modulation and pump overrun to better match the system.

Repair Difficulty

Medium 3/5