Weil-McLain Evergreen TEMPERATURE SENSOR FAULT — Temperature Sensor Shorted or Disconnected, or Dual Sensors Spread by More Than 10° F
TEMPERATURE SENSOR FAULT
Temperature sensor shorted or disconnected, or dual sensors spread by more than 10° F. This fault occurs if a temperature sensor has electrically shorted or become disconnected, or if dual temperature sensor values have spread by more than 10º F while the burner is on. The table classifies it as Will automatically reset if the condition clears. Automatically resets when sensors are within 10º F..
Applies to
This sensor fault code is displayed by the Evergreen control (display messages) on Evergreen models (EVG 110, EVG 155, EVG 220, EVG 299, EVG 399), as documented in Evergreen Boiler Manual sizes 220–399, doc 550-100-211/0122 (fault set matches doc 550-100-210 for sizes 110/155) (550-100-211/0122). Codes can differ between controller generations, so always check the manual that matches your unit.
- Weil-McLain Evergreen
- Weil-McLain Evergreen EVG-110
- Weil-McLain Evergreen EVG-155
- Weil-McLain Evergreen EVG-220
- Weil-McLain Evergreen EVG-299
- Weil-McLain Evergreen EVG-399
Controller: Evergreen control (display messages). Source manual: 550-100-211/0122 (2022-01).
Why a code is not a diagnosis
A sensor code usually means the sensor, its wiring or its mounting is faulty; the physical condition the sensor measures (temperature, pressure, flow) may be perfectly normal.
Safe things to observe
- Note the code; there is no homeowner-accessible check for sensor circuits.
- If the appliance still runs, watch whether the code returns and report it when you call.
Do not
- Do not open the appliance to test or replace sensors yourself.
How professional service helps
- A technician measures the sensor and harness against the manual's values and replaces the faulty component.
- Combustion and safety devices are verified with an analyser and the manufacturer's procedure after any repair.
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Parts and service
Parts commonly involved
These parts appear in the documented text for this alert. A code reports a condition, not a failed part — a technician confirms the cause by testing before anything is replaced.
Burner assembly
The burner assembly is where gas and air meet and burn inside a boiler, and its condition decides whether combustion is clean or makes carbon…
What a technician checks →Boiler sensors (thermistors)
Boiler sensors are small temperature probes, usually thermistors, that tell the control how hot the water and flue gases are so it can fire safely…
What a technician checks →
Service for this alert
- Gas Boiler Repair
Licensed gas technicians from ROMA Heating & Cooling diagnose and repair residential and light-commercial gas boilers across…
Every boiler part explained — what it does, how it fails and what a technician checks.
Documented for Weil-McLain Evergreen.
Frequently asked questions
Can I clear this code myself?
Clearing a code without fixing its cause usually just brings it back. Note the code, check the safe items on this page, then call a licensed technician. If your appliance manual describes a user reset for this exact code and it stays away, no call may be needed.
Boiler locked out? Call with the alert text ready.
The brand, model and this alert are passed along when you request service online, so the technician arrives prepared.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
- Evergreen Boiler Manual sizes 220–399, doc 550-100-211/0122 (fault set matches doc 550-100-210 for sizes 110/155) · 550-100-211/0122 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.