Ideal NTC Sensor 178130

The Ideal 178130 is an NTC (negative temperature coefficient) sensor used on Ideal Commercial heating appliances. It is a thermistor probe that changes resistance as water temperature rises, feeding that signal back to the appliance control board so the boiler can regulate flow and return temperatures accurately.

This sensor is listed against the Ideal Commercial Imax XEL range, including the 715kW, 1090kW and 1240kW output models. It is supplied under the Ideal Domestic Boiler Spares brand and carries the alternative part number 9051215.

• The appliance locks out or shuts down shortly after firing, with a temperature-related fault code on the display.
• Flow or return temperature readings on the controls are erratic, stuck, or clearly wrong compared with a clamp thermometer.
• Domestic hot water or heating output fluctuates, with the burner cycling more often than normal.
• The boiler runs for a short period and then trips, particularly once the system has warmed up.
• A resistance check across the sensor terminals gives a reading outside the expected curve for the ambient or water temperature at the time of testing.

• Confirm the appliance model and serial number against the compatibility list, as the Imax XEL range uses more than one sensor position and variant.
• Cross-reference the number on the existing sensor against 178130 or 9051215 before ordering.
• Inspect the sensor pocket, O-ring and retaining clip on removal, as these are commonly disturbed when the probe is withdrawn.
• Work on the appliance only with the electrical supply isolated, and follow the manufacturer's commissioning checks after fitting.