Heatline Combi boiler’s faulty mechanical controls


My newly bought Heatline combi boiler is facing a strange issue from last 3-4 days. The temperature of the boiler seems extremely hot or cold vice versa that it displays on the thermostat. Moreover, the thermostat is buzzing a lot. I am unable to understand the actual reason behind it. Please help me to sort it out

Thanks in advance


Hello Pat, it is quite common in the majority of the boiler. This will give the impression that there are some other faults however; they are only electrical. Well, this can be a mechanical timer, thermostat or the frost thermostat. The controls of the boiler are expected to be faulty if:

  • The boiler turns off and one when it is not meant to
  • The thermostat of the boiler is not clicking & buzzing
  • You are getting extremely hot water
  • The radiators controllers are not decreasing or increasing temperature according to the setting

Sometimes, it is much better & economical to replace the faulty controls instead of repairing them.