Within this Johnson & Starley Thermostats category we list main boiler control thermostats which are normally a secondary boiler protection device as most systems
are now controlled by external thermostats, but it adds simple protection of the Johnson & Starley appliance by managing the internal temperature of the boiler or
appliance. Also Johnson & Starley Overheat thermostats which switch the boiler off in the unlikely event of the boiler overheating. Hi and low limit thermostats which
basically govern the higher and lower temperatures required for the Johnson & Starley appliance.