Chaffoteaux Overheat Thermostat 105C 61010191

The Chaffoteaux 61010191 is an overheat thermostat with a 105°C cut-out, used as a safety limit device on a range of Chaffoteaux gas boilers. It monitors boiler temperature and breaks the circuit if the set point is exceeded, shutting the appliance down before overheating occurs. It is listed under thermostats in the gas boiler spares range.

• The boiler locks out repeatedly with no other fault found, particularly after the appliance has been running for some time.
• The overheat trip operates at normal operating temperature, cutting the burner before the boiler reaches its usual set point.
• The thermostat shows no continuity across its terminals when cold, or fails to open when heated.
• The boiler requires a manual reset far more often than it used to.
• Visible damage, corrosion or a loose or burnt connection at the thermostat terminals.

• Confirm the boiler model against the fit list above, as the same appliance family is supplied in several variants.
• Check the existing thermostat's cut-out temperature marking matches 105°C.
• Inspect the wiring and terminal condition before fitting, since a poor connection can mimic a failed thermostat.
• If the boiler has tripped on overheat, establish the underlying cause — circulation, pump or scale — before replacing the limit device.