Worcester Bosch Control Thermostat 87161078740

The Worcester Bosch 87161078740 is a control thermostat supplied by Worcester Bosch for its Boulter Camray 5 and Cam 5 combi appliance range. It sits in the heating circuit and senses water temperature, switching the burner on and off to hold the appliance at the temperature set on the control dial. When it drifts out of calibration or fails, the appliance loses accurate control of its heating output.

• The appliance runs but the heating circuit never reaches the temperature set on the control dial.
• The burner cycles on and off far more often than normal, or short-cycles before the system is up to temperature.
• Radiator or stored water temperature drifts noticeably between cycles instead of holding steady.
• Turning the control thermostat up or down has little or no effect on appliance behaviour.
• The appliance locks out intermittently with no other obvious fault found during diagnosis.

• Confirm the appliance model and serial number against the compatibility list, as the thermostat is used across several Camray 5 and Cam 5 combi variants.
• Check the existing thermostat against the alternative numbers 1021122 and EL00237 before ordering, as earlier builds may carry a different number on the label.
• Inspect the thermostat pocket and any sealing washer or O-ring at the same time, and replace if worn or hardened.
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.