Lochinvar Inlet Sensor Fault: Inlet Sensor Fault
What the Lochinvar Inlet Sensor Fault fault means, what causes it, and why it's a job for a licensed BC gas technician — not a DIY reset.
Severity
Moderate — book a service visit
What the Lochinvar Inlet Sensor Fault fault means
The inlet (return) temperature sensor is reading out of range.
On Lochinvar Knight, WHN and SMART System series, Inlet Sensor Fault is a temperature-sensor fault. It is a protective response — the boiler is telling you something needs attention, and the safe, lasting fix is a proper diagnosis rather than repeated resets.
Symptoms you may notice
- Erratic heating or hot-water temperature
- Boiler locks out or refuses to fire
- Wrong temperature shown on the display
Common causes of Lochinvar Inlet Sensor Fault
Why this is not a DIY fix
A faulty NTC/thermistor reading (open, shorted or out-of-range) can mask a real overheating or circulation problem. A technician verifies whether the sensor itself has failed or whether it is correctly reporting a deeper fault before any part is replaced.
In British Columbia, gas work must be performed by a TSBC-licensed gas fitter. GasBoilers.ca — a CanroHeat division — sends Red Seal–certified, gas-licensed technicians who diagnose the true cause, repair it correctly, and verify safe operation before they leave.
How our technicians diagnose & repair it
- 1Measure sensor resistance against the manufacturer temperature curve
- 2Inspect wiring, connectors and sensor mounting/contact
- 3Confirm actual water temperature with calibrated instruments
- 4Replace the sensor and verify correct readings across the range
Related Lochinvar codes
Lochinvar Inlet Sensor Fault — FAQ
What does the Lochinvar Inlet Sensor Fault fault mean?
The inlet (return) temperature sensor is reading out of range. On Lochinvar Knight, WHN and SMART System series, this is categorised as a temperature-sensor fault.
What causes Lochinvar Inlet Sensor Fault?
The most common causes are: Failed sensor; Wiring fault; Connector corrosion. A licensed technician confirms which one applies before any part is replaced.
Can I fix Lochinvar Inlet Sensor Fault myself?
No. A faulty NTC/thermistor reading (open, shorted or out-of-range) can mask a real overheating or circulation problem. A technician verifies whether the sensor itself has failed or whether it is correctly reporting a deeper fault before any part is replaced. Repeatedly resetting the boiler without fixing the root cause can be unsafe and can cause further damage. Call GasBoilers.ca at 604-359-1081 for a licensed diagnosis.
Is the Lochinvar Inlet Sensor Fault fault dangerous?
This is a protective fault — the boiler has shut down a function to protect itself. It is best diagnosed promptly by a licensed technician so the underlying cause does not lead to a more expensive failure.
How much does it cost to fix Lochinvar Inlet Sensor Fault in Greater Vancouver?
Cost depends on the root cause and any parts needed. We start with a flat-rate diagnostic, then quote the repair before any work begins — no surprises. Call 604-359-1081 for current pricing and same-day availability.
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Lochinvar showing Inlet Sensor Fault? We'll fix it right.
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