Weil-McLain Boiler Error Codes — Meanings, Causes & Repair in Greater Vancouver

Seeing a fault code on your Weil-McLain boiler? This guide explains what the most common Weil-McLain boiler error codes mean, what’s safe to check yourself, and when to call HeatLand’s licensed, TSBC-certified gas technicians for Weil-McLain boiler repair across Metro Vancouver and the Fraser Valley.

The codes below apply across common Weil-McLain models (Evergreen, ECO, ECO Tec, Ultra). Meanings follow Weil-McLain’s documented fault codes — always confirm against your unit’s own manual, because exact wording can vary by model, control board and firmware.

How to read Weil-McLain boiler error codes

Weil-McLain uses TWO different fault-display systems. (1) Modern boilers with the U-Control / EVG color graphic display — Evergreen, ECO Tec Series 2, and the current Ultra Series 3 — do NOT use numeric codes; they show a PLAIN-TEXT fault NAME on the display (e.g. IGNITION FAULT, FLAME FAULT, LOW WTR CUTOFF OPEN, BLOWER FAULT). The display banner/screen turns RED on an error or limit event; a SOLID red screen is a non-lockout error, while a FLASHING red screen (toggling red to gray) means a lockout condition that may need a manual reset. The control also logs the last 3-6 lockouts under DIAGNOSTICS > PAST ERRORS with a FAULT NAME and FAULT TYPE. (2) The ORIGINAL/older Ultra gas boilers (Ultra-80/105/155/230/310, roughly 2002-2008, e.g. Ultra-105 service manual 550-100-090) use a 2-digit NUMERIC code: a HARD lockout shows the letter 'E' followed by a 2-digit number (the display flashes the 'E' then the last two digits, e.g. E-02), requires manual reset; a SOFT lockout shows '9' then a 2-digit number and auto-clears when the condition corrects; a single status digit (0-8, H, L) shows the current operating phase. The text below pairs each item with the series/display it applies to.

Weil-McLain boiler error codes & what they mean

These are the Weil-McLain boiler codes our Greater Vancouver technicians see most. Anything marked pro repair involves gas, electrical, sealed-combustion or control-board work that must be done by a licensed gas technician (TSBC-certified in BC) — never open gas or electrical components yourself.

Code	What it usually means	Common causes	Safe to check yourself
IGNITION FAULT (text display) / E-02 (older Ultra numeric)	Ignition lockout — the boiler went through 5 ignition attempts and never detected (or never reached the minimum flame-sense threshold for) a flame, so it locked out. On U-Control boilers it auto-resets after about 1 hour or can be manually reset; the older Ultra shows hard-lockout E-02 requiring manual reset pro repair	No gas supply / manual gas cock closed or low incoming gas pressure; Blocked or frozen condensate trap/drain allowing condensate to back up into the heat exchanger; Fouled, worn, bent, or faulty ignition electrode / wrong spark gap	Confirm the gas is on and other gas appliances work; Check the condensate drain line/trap is not blocked or frozen; thaw the visible outdoor section with warm (not boiling) water if frozen; Confirm the vent and air intake terminations outside are clear of snow, ice, leaves, or debris
IGNITION 1 FAULT (ECO Tec)	Ignition lockout, stage 1 — the boiler went through 5 ignition attempts and never detected flame, or the flame-sense value never reached the minimum threshold for the boiler model. Auto-resets after about 1 hour or by manual reset pro repair	Blocked condensate trap letting condensate accumulate inside the heat exchanger; Loose ignition cable connection or fouled/worn/faulty igniter; No or low gas supply	Confirm the gas supply is on; Check the condensate drain/trap is clear and not frozen; Check vent and air intake terminations outside are unobstructed
IGNITION 2 FAULT (ECO Tec)	Ignition lockout, stage 2 — the boiler went through 5 ignition attempts and did not meet the RUNNING flame threshold for the boiler model (flame was sensed at light-off but was not strong enough to hold). Auto-resets after about 1 hour or by manual reset pro repair	Weak or unstable flame from incorrect combustion settings; Fouled or worn ignition/flame-sense electrode; Low or fluctuating gas pressure	Confirm the gas supply is on; Check vent and air intake terminations outside are clear; Perform a single manual reset and observe whether it returns
FLAME LOSS FAULT (ECO Tec)	Flame-loss lockout — the boiler went through 5 ignition attempts and the flame signal dropped below the proof-of-ignition level during the stabilization period of the ignition sequence (flame established but was lost while stabilizing) pro repair	Fouled or worn flame-sense electrode; Marginal/incorrect combustion (gas pressure or air settings); Condensate or debris affecting the burner/heat exchanger	Confirm the gas supply is on; Check vent and air intake terminations outside are clear; Perform a single manual reset and observe whether it returns
FLAME FAULT / FALSE FLAME (text display) / E-00 (older Ultra numeric)	False flame — the control detected (or sensed) a flame when there should be none (for example flame still present after the gas valve closed, or flame detected on start-up before ignition). On the older Ultra this is hard-lockout E-00 'flame detected on startup.' Requires manual reset pro repair	Gas valve not closing fully / leaking by; Burner running too hot from incorrect combustion; Faulty or contaminated flame-sense electrode giving a false flame signal	Perform a single manual reset and note whether the fault returns immediately (a repeat fault should be left to a technician)
BLOWER FAULT (text display) / E-28 (older Ultra numeric)	Blower fault — the blower could not reach the required speed, or did not return to 0 RPM when it was commanded off. On the older Ultra, hard-lockout E-28 means 'no signal from blower.' U-Control boilers auto-retry after about 1 hour and restart if corrected; the ECO Tec splits this into Blower Fault 1 (won't stop), Blower Fault 2 (won't reach prepurge/ignition speed or failed calibration), and Blower Fault 3 (speed out of range) pro repair	Loose or damaged blower wiring (low-voltage and line-voltage harnesses); Failed or seized blower motor; Blower needs recalibration (ECO Tec)	Confirm the boiler has power and is switched on; Perform a single manual reset and observe whether it clears
GAS VALVE FAULT / GAS RELAY FAULT 1-4 (text display) / E-07 (older Ultra numeric)	Gas valve / gas relay circuit fault — the control detected a problem in the gas-valve output circuit. The control performs an automatic retry; if the retry is unsuccessful it locks out and retries about 1 hour after lockout, restarting if the condition cleared or requiring manual reset if it is still present. On the older Ultra the equivalent hard-lockout codes are gas-valve relay / internal control faults pro repair	Wiring problem at the gas valve output circuit; Faulty gas valve; Internal control fault (replace control if the lockout recurs)	Perform a single manual reset and note whether the fault recurs (a repeat fault needs a technician)
LOW WTR CUTOFF OPEN	Low-water cutoff open — the internal (or external) low-water cutoff contacts opened, indicating the system may be low on water. On U-Control boilers it auto-resets if the contacts are open less than 5 seconds; longer than 5 seconds (or on ECO Tec, any open) requires a manual reset of the control pro repair	Genuine low-water condition in the system (low pressure / loss of water); Wiring fault between the low-water cutoff and the control; Dirty LWCO probe	Read the system pressure gauge — typical cold fill is about 12 psi; very low pressure suggests water loss; Look for visible leaks around the boiler and piping; Perform a single manual reset only after confirming pressure is normal; if pressure is low or the fault recurs, call a technician
LIMIT OPEN (text display) / E-12 (older Ultra numeric)	External limit open — a manual-reset or automatic-reset external limit/safety device wired into the boiler's limit circuit has opened (or its jumper is missing). The automatic-reset limit re-closes about 2.5 minutes after the device closes; a manual-reset limit fault must be reset on the display. On the older Ultra this is hard-lockout E-12 'external limit open.' pro repair	An external safety control (e.g. additional high-limit, LWCO, spill switch) has tripped; Loose wiring at the limit circuit (control plug P13 on U-Control boilers); Missing factory jumper across the MAN LIMIT or AUTO LIMIT terminals when no external limit is used	If an external safety device tripped, do not bypass it — call a technician to find why it opened; Perform a single manual reset only once; if it reopens, call a technician
HIGH TEMP LIMIT (text display) / E-18 / E-19 (older Ultra numeric)	High temperature limit — a boiler temperature sensor reached the High Temp Limit setting (no higher than 200 F on U-Control boilers). On the older Ultra, hard-lockout E-18 = outlet water temperature exceeded ~210 F and E-19 = return water temperature exceeded ~210 F. Requires manual reset pro repair	Poor water flow through the boiler — closed isolation valve, air-bound system, or stuck/failed circulator; Circulator not programmed correctly in the control; High-limit setting too low relative to the target temperature	Read the system pressure gauge and confirm it is in the normal range (around 12 psi cold); Confirm the circulator/pump is running and the system is not air-bound (you may hear no flow); Perform a single manual reset; if it recurs, call a technician
FLUE TEMP TOO HIGH (text display) / E-52 (older Ultra numeric)	Flue temperature too high — the flue-temperature sensor exceeded its limit. On U-Control boilers ~210 F is a warning and ~220 F is a lockout requiring manual reset (auto-resets if it drops below 210 F for 2.5 minutes). On the older Ultra, hard-lockout E-52 = flue temperature above ~225 F pro repair	Abnormal wear, scale, or buildup in the heat exchanger / combustion chamber or flueways; Vent system wear or damage; Shorted or open flue-temperature sensor	Confirm vent and air intake terminations outside are clear; Perform a single manual reset; if it recurs, stop and call a technician (this fault can indicate a heat-exchanger or venting problem)
TEMPERATURE SENSOR FAULT / E-13 / E-14 / E-31 / E-32 / E-36 / E-37 (older Ultra numeric)	Temperature sensor fault — a boiler temperature sensor (flue, outdoor, return, supply, or system) has electrically shorted or become disconnected (open), or two paired sensors disagree by more than 10 F. On the older Ultra, individual hard/soft codes identify the specific sensor: E-31/E-36 = outlet (supply) sensor shorted/open, E-32/E-37 = return sensor shorted/open, and related numbers for flue sensors. Most sensor faults auto-clear when the condition corrects pro repair	Loose or damaged sensor wiring / connector; Failed (out-of-spec) temperature sensor; Two paired sensors reading more than 10 F apart	None beyond a single power-cycle/reset — sensor diagnosis requires opening the boiler and is a technician task
OUTDOOR SENSOR ERROR	Outdoor temperature sensor error — the outdoor sensor reads short or open. This is a warning only: the boiler keeps running and targets Supply Max until the outdoor sensor is restored (when the sensor is used for outdoor-reset target adjustment). Auto-resets when the condition clears pro repair	Loose or damaged outdoor-sensor wiring; Failed (out-of-spec) outdoor sensor; Control fault if it persists after sensor checks	None invasive — confirm heat is still being delivered; the boiler continues to run as a warning. Sensor replacement is a technician task
AIR PRESSURE Switch Open (text display) / E-61 (older Ultra numeric)	Air-pressure switch open — the air-pressure-switch connection is open. Reset using the manual reset screen on U-Control boilers. On the older Ultra, hard-lockout E-61 = airflow circuit failure pro repair	Wrong boiler size selected in the control vs. the rating label; Air-pressure switch wiring/connection fault (e.g. J22 on ECO Tec, P7 on Evergreen); Missing or incorrect factory jumper	Confirm vent and air intake terminations outside are clear of obstructions; Perform a single manual reset; if it recurs, call a technician
Closure Switch fault	Proof-of-closure / closure-switch fault — the closure-switch connection (proof-of-closure, flow switch, or combustion-air-damper proof) is open. The control goes into a soft lockout (about 3.5-4 minutes), retries, and lengthens the lockout on repeated failures before a manual lockout pro repair	Missing or wrong jumper if no closure device is used; Flow switch open — wrong pump running, wiring fault, or switch not closing; Combustion-air damper not opening / no voltage to the damper	None invasive — this requires checking jumpers, a flow switch, or a damper inside the boiler, which is a technician task
TEMP RISE TOO QUICKLY	Temperature rise too quickly — during the first two minutes after the burner lights, the supply-water temperature in the heat exchanger rose faster than the allowed rate (about 2 F per second on Evergreen, 10 F per second on ECO Tec), indicating insufficient flow. Auto-resets after a 1-minute delay; after 5 auto-resets in the same heat demand a manual reset is required pro repair	Low or no water flow through the boiler (air-bound system, closed valve, wrong/failed circulator); Wrong circulator size or speed for the boiler/system; Sensor connection problem	Read the system pressure gauge and confirm it is normal (around 12 psi cold); Confirm the circulator is running and the system is not air-bound; Perform a single manual reset; if it recurs, call a technician
SUPPLY 58 F > RETURN / Supply 60F > Return / E-25 (older Ultra numeric)	Supply far hotter than return — the boiler-out temperature exceeded the boiler-in (return) temperature by more than the allowed difference (58 F on Evergreen, 60 F on ECO Tec), indicating very low flow. The boiler soft-locks and retries with progressively longer delays; on the older Ultra, E-25 = temperature rise greater than 58 F pro repair	Insufficient water flow through the boiler; Undersized or incorrectly installed circulator; Wiring fault to the circulator	Read the system pressure gauge and confirm it is normal; Confirm the circulator is running; The boiler usually retries on its own; if it persists, call a technician
RETURN > SUPPLY	Return hotter than supply — the return-water temperature is more than 10 F higher than the corresponding supply temperature, which usually points to reversed flow or mis-located system sensors. Auto-resets when the condition clears pro repair	Boiler or system circulator pumping the wrong direction / installed backwards; System supply and return sensors located on the boiler loop instead of system piping, or swapped at the terminals; Sensors too close to the boiler loop and being heated inaccurately	None invasive — this is a flow-direction or sensor-placement issue for a technician to correct
SUPPLY WATER TEMPERATURE TOO HIGH	Supply water temperature too high — the system supply temperature went above 200 F while the burner was running. Auto-resets when the supply temperature drops below 200 F pro repair	System circulator running backwards or not pushing water through the system; Low system flow; Circulator wiring/orientation fault	Confirm the circulator is running; Read the system pressure gauge and confirm it is normal; if the fault persists, call a technician
DHW Outlet > Boiler Out	Combi domestic-hot-water fault — on combi models, the DHW outlet sensor read more than 10 F above the boiler-outlet sensor for at least 30 seconds of firing, indicating a DHW flow or 3-way-valve problem. Clears when the DHW outlet falls below the boiler outlet plus 7 F pro repair	Insufficient DHW water flow from the installed circulators; A required valve is closed; 3-way diverter valve not operating correctly	None invasive — diverter-valve and circulator diagnosis is a technician task
Wrong J6 Jumper / Configuration fault	Voltage-configuration or configuration fault — on ECO Tec, the J6 voltage-configuration jumper is installed incorrectly (24 VAC jumper used where 120 VAC is required, or vice-versa, or no jumper), reported as Voltage Too High / Too Low / No Voltage Detected. The related Configuration fault means the data in the safety micro does not match the application micro. Clears when corrected pro repair	J6 voltage jumper missing or wrong type; Loose J6 connector; Mismatched/corrupted control configuration (may need a factory-default reset)	None invasive — jumper and configuration checks require opening the control and are a technician task
DISPLAY COMM Fault / Communication errors	Display communication fault — communication between the control board and the display was lost for about 30 seconds. The boiler keeps operating; the message auto-resets when communication is re-established. (Improper connections can also make the display show the wrong model number.) pro repair	Loose connector between the control, communications board, and display; Damaged communication wire harness; Failed display module	A single power-cycle of the boiler at the switch may restore the display; if it persists, call a technician
Hardware Fault / Control fault / Hardware A2D Fault / Flame Circuit Fault / E-03 / E-44 / E-60 (older Ultra numeric)	Internal control / hardware fault — the control's microcontroller detected a RAM or ROM error, an internal voltage-reference (A2D) reading out of range, a flame-circuit discharge problem, or a parameter-read error. On the older Ultra these appear as internal-control hard-lockout codes (e.g. E-03, E-44, E-60). Many can be cleared with a manual reset / power cycle; if they persist the control (main board) must be replaced pro repair	Transient RAM/ROM or internal voltage error; Electrical surge or noise on incoming power; Failed control board	Power-cycle the boiler once at the switch and try a single manual reset; if it recurs, the control likely needs replacement by a technician
E-04 (older Ultra numeric)	Power lost after lockout — on the older Ultra, the boiler was already in a lockout when incoming power was interrupted; the control retains the lockout (or reports the power loss) and requires a manual reset. It can also be associated with AC voltage fluctuations on the incoming power pro repair	Power interruption while the boiler was already locked out (so the original underlying fault still needs to be found); Unstable / fluctuating incoming AC voltage	Confirm the boiler has steady power (breaker on, service switch on); Perform a single manual reset; if a different fault then appears, that is the real issue to address; If it recurs, call a technician
Nothing shown on display / boiler will not respond	No display / dead control — the control is not receiving 24 V (or 120 V) power, or display communication is lost. This is a power/wiring/fuse condition rather than a numbered fault: a blank screen with no boiler response usually means a blown control fuse, a tripped switch/breaker, or a transformer/wiring problem pro repair	Tripped breaker or service switch turned off; Blown low-voltage (3-amp / 4-amp) or line-voltage (12-amp) control fuse; Failed transformer or wiring fault	Confirm the boiler's service switch is on and the circuit breaker has not tripped; Confirm there is power at the wall switch/outlet feeding the boiler; Do NOT open the control or replace fuses yourself — fuse and transformer checks are a technician task

Weil-McLain boiler codes we get called for most

IGNITION FAULT (text display) / E-02 (older Ultra numeric) — Ignition lockout — the boiler went through 5 ignition attempts and never detected (or never reached the minimum flame-sense threshold for) a flame, so it locked out. On U-Control boilers it auto-resets after about 1 hour or can be manually reset; the older Ultra shows hard-lockout E-02 requiring manual reset

Typical causes include no gas supply / manual gas cock closed or low incoming gas pressure; blocked or frozen condensate trap/drain allowing condensate to back up into the heat exchanger; fouled, worn, bent, or faulty ignition electrode / wrong spark gap. A few things are safe to check yourself (Confirm the gas is on and other gas appliances work; Check the condensate drain line/trap is not blocked or frozen; thaw the visible outdoor section with warm (not boiling) water if frozen), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes IGNITION FAULT (text display) / E-02 (older Ultra numeric) on Weil-McLain boilers throughout Greater Vancouver.

AIR PRESSURE Switch Open (text display) / E-61 (older Ultra numeric) — Air-pressure switch open — the air-pressure-switch connection is open. Reset using the manual reset screen on U-Control boilers. On the older Ultra, hard-lockout E-61 = airflow circuit failure

Typical causes include wrong boiler size selected in the control vs. the rating label; air-pressure switch wiring/connection fault (e.g. j22 on eco tec, p7 on evergreen); missing or incorrect factory jumper. A few things are safe to check yourself (Confirm vent and air intake terminations outside are clear of obstructions; Perform a single manual reset; if it recurs, call a technician), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes AIR PRESSURE Switch Open (text display) / E-61 (older Ultra numeric) on Weil-McLain boilers throughout Greater Vancouver.

FLUE TEMP TOO HIGH (text display) / E-52 (older Ultra numeric) — Flue temperature too high — the flue-temperature sensor exceeded its limit. On U-Control boilers ~210 F is a warning and ~220 F is a lockout requiring manual reset (auto-resets if it drops below 210 F for 2.5 minutes). On the older Ultra, hard-lockout E-52 = flue temperature above ~225 F

Typical causes include abnormal wear, scale, or buildup in the heat exchanger / combustion chamber or flueways; vent system wear or damage; shorted or open flue-temperature sensor. A few things are safe to check yourself (Confirm vent and air intake terminations outside are clear; Perform a single manual reset; if it recurs, stop and call a technician (this fault can indicate a heat-exchanger or venting problem)), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes FLUE TEMP TOO HIGH (text display) / E-52 (older Ultra numeric) on Weil-McLain boilers throughout Greater Vancouver.

BLOWER FAULT (text display) / E-28 (older Ultra numeric) — Blower fault — the blower could not reach the required speed, or did not return to 0 RPM when it was commanded off. On the older Ultra, hard-lockout E-28 means 'no signal from blower.' U-Control boilers auto-retry after about 1 hour and restart if corrected; the ECO Tec splits this into Blower Fault 1 (won't stop), Blower Fault 2 (won't reach prepurge/ignition speed or failed calibration), and Blower Fault 3 (speed out of range)

Typical causes include loose or damaged blower wiring (low-voltage and line-voltage harnesses); failed or seized blower motor; blower needs recalibration (eco tec). A few things are safe to check yourself (Confirm the boiler has power and is switched on; Perform a single manual reset and observe whether it clears), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes BLOWER FAULT (text display) / E-28 (older Ultra numeric) on Weil-McLain boilers throughout Greater Vancouver.

Is it safe to keep running a Weil-McLain boiler with a fault code?

Most Weil-McLain fault codes put the boiler into a safe lockout for a reason. You can safely check the basics — gas supply on, power on, the thermostat calling for heat, system pressure in the normal range, and the condensate drain not frozen or blocked (a common cause in Vancouver cold snaps) — and restart it once. If the code returns, stop and book a technician. If you ever smell gas, leave the building and call your gas utility’s emergency line or 911 first. If a carbon-monoxide alarm sounds, get everyone out and call 911.

Weil-McLain boiler repair across Greater Vancouver

HeatLand has kept Metro Vancouver homes comfortable since 1999. Our licensed, insured technicians diagnose and repair Weil-McLain boilers — ignition faults, flame and sensor errors, low-pressure and pump problems, fan and flue faults, and control-board issues — including units we didn’t install. We’re brand-agnostic, carry common parts, and give you an honest repair-or-replace assessment with upfront pricing and a free estimate. If your boiler is beyond economical repair, we’ll show you right-sized, high-efficiency replacement options and the rebates available.

Need it sorted fast? We offer priority emergency boiler repair. Explore Boiler services, browse all boiler error codes by brand, or request a free estimate.

Weil-McLain boiler service areas

We repair Weil-McLain boilers across Greater Vancouver and the Fraser Valley, including:

Weil-McLain boiler error code FAQs

Can I reset my Weil-McLain boiler myself?

Yes — power-cycling the reset button once is generally safe after you’ve checked the basics (gas supply on, power on, the thermostat calling for heat, system pressure in the normal range, and the condensate drain not frozen or blocked (a common cause in Vancouver cold snaps)). If the boiler faults again right away, stop and note the code — repeatedly resetting a boiler that keeps locking out can mask a real problem. Call a licensed, TSBC-certified gas technician to diagnose it.

What does the Weil-McLain IGNITION FAULT (text display) / E-02 (older Ultra numeric) code mean?

On Weil-McLain boilers, IGNITION FAULT (text display) / E-02 (older Ultra numeric) commonly indicates ignition lockout — the boiler went through 5 ignition attempts and never detected (or never reached the minimum flame-sense threshold for) a flame, so it locked out. on u-control boilers it auto-resets after about 1 hour or can be manually reset; the older ultra shows hard-lockout e-02 requiring manual reset. Confirm the exact meaning against your unit’s manual — codes can vary by model and series — and have the repair done by a licensed, TSBC-certified gas technician. HeatLand fixes this across Greater Vancouver.

Do you repair Weil-McLain boilers you didn’t install?

Yes. HeatLand is brand-agnostic and services Weil-McLain boilers throughout Metro Vancouver and the Fraser Valley, whether or not we installed the unit. We carry common parts and give you an honest repair-or-replace assessment.

Is a Weil-McLain boiler fault code an emergency?

No heat in cold weather is worth treating urgently. If you ever smell gas, leave the building and call your gas utility’s emergency line or 911 first. If a carbon-monoxide alarm sounds, get everyone out and call 911. For priority boiler repair across Greater Vancouver, call (604) 330-3812.

How much does Weil-McLain boiler repair cost in Vancouver?

It depends on the fault. Many Weil-McLain codes point to sensors, ignition or pump parts — usually far cheaper than replacement. We give upfront pricing and a free estimate before any work.

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