Vokera Short cycling due to control settings or system mismatch

Thermostat causes boiler to short-cycle (frequent on/off) even when house is not warm

Advertisements

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.

Advertisements

Possible Causes

Cycle rate set too high in thermostat, Oversized boiler for small system, Thermostat installed too close to radiator, Incorrect minimum run time configuration

How to Fix / Troubleshooting

Safety first: No special hazards.

  • Adjust cycle rate: In the thermostat installer settings, reduce the cycle rate (e.g., from 6 cycles/hour to 3) or enable TPI/OpenTherm modulation.
  • Increase minimum run time: Set a longer minimum on time (e.g., 5–10 minutes) to prevent rapid cycling.
  • Relocate thermostat: Move the thermostat away from radiators and heat sources so it senses room temperature more accurately.
  • Check boiler settings: On the boiler, reduce the CH flow temperature slightly to lengthen run times and reduce overshoot.
  • If cycling remains severe: Consult a heating engineer to review boiler sizing and system design.
Advertisements

Repair Difficulty

Medium 3/5
Advertisements