Baxi Overheat Thermostat 231825BAX

The Baxi 231825BAX is an overheat thermostat manufactured by Baxi for the Solo 2 RS range of gas boilers. It is a safety device mounted on the appliance heat exchanger, where it monitors temperature and interrupts the burner circuit if the boiler runs hotter than it should. Once tripped, the boiler will not fire again until the thermostat has cooled and the reset condition is cleared, which protects the heat exchanger and the surrounding components from damage.

• The boiler fires and then cuts out shortly afterwards, with the overheat trip operating before the appliance reaches its normal working temperature.
• Repeated lockouts or shutdowns with no other fault found on the burner, gas or water side.
• The boiler will not restart after cooling, or needs repeated manual intervention to run.
• The thermostat shows no continuity across its terminals when cold, or the reading is erratic compared with a known good unit.
• Visible damage, corrosion or a loose or degraded mounting at the thermostat position on the heat exchanger.

• Check the GC number on the appliance data badge against the numbers listed above before ordering, as the Solo 2 RS variants use different thermostat fitments.
• Confirm the part number on the existing thermostat, and check whether the previous number 9906171 or the alternative number 1112350 is marked on the component being replaced.
• Note the full appliance model and serial number so the correct thermostat is matched to the boiler.
• Inspect the thermostat seating and any seal or gasket at the mounting point, and replace these if they are perished or damaged.