Burnham Boiler Error Codes — Meanings, Causes & Repair in Greater Vancouver

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

The codes below apply across common Burnham models (Alpine, K2, Aspen, ESC). Meanings follow Burnham’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 Burnham boiler error codes

Burnham (U.S. Boiler Company) condensing/combi boilers (Alpine, K2, Aspen) use the Sage (Sage2.1/2.2/2.3) boiler control, which reports a numbered Soft Lockout or Hard Lockout. A Soft Lockout makes the display turn red and the 'Help' button blink; the boiler restarts automatically once the condition clears. A Hard Lockout also turns the display red but requires a manual reset (Reset button on the 'Active Fault' display or on the Sage control) after the fault is corrected. On the LED/two-digit displays, soft codes appear after a flashing pattern and hard codes flash the letter 'E' followed by the number. The Sage soft/hard code set is the same across Alpine, K2 and Aspen; minor threshold differences exist between models (e.g. stack high-limit 204F on early Alpine vs 214F on K2/Aspen). The ESC is a SEPARATE product: it is an 85% AFUE chimney-vented CAST-IRON (non-condensing) gas boiler that uses the IQ Control System, NOT the Sage control. The ESC's IQ Boiler Control flashes 'Err' followed by a number for faults and 'StA' followed by a number for normal status states – a completely different code set, included separately below.

Burnham boiler error codes & what they mean

These are the Burnham 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
Soft Lockout 1	Soft lockout: minimum time between starts has not been reached (normal anti-short-cycle delay used to avoid excessive cycling) pro repair	normal operation – the control is enforcing the minimum off-time between burner starts	no action needed – this is a normal delay; the boiler will restart on its own; confirm the thermostat is calling for heat
Soft Lockout 2	Soft lockout: Boiler Safety Limit / External Limit circuit open (terminals J6-1, 2 or 3 open) pro repair	water temperature above the external limit setting; external limit device defective or jumper not installed when no external device is used; optional low-water cutoff indicating low water	check the system pressure gauge and top up via the filling loop per the user manual if low; confirm power and the thermostat call for heat; do not open the limit wiring; call a licensed technician if it recurs
Soft Lockout 3	Soft lockout: Boiler Safety Limit open / Blocked Flue or Inlet switch open (ILK off; terminals J5-1 open) pro repair	blocked or restricted flue or air-intake pipe; blocked vent causing the air pressure switch to open after the blower starts; loose wiring to the limit/switch	check the outside vent/air-intake terminal for visible obstruction (snow, debris, nests) from a safe position; confirm power to the boiler; do not dismantle the flue or wiring; call a licensed technician if it recurs
Soft Lockout 7	Soft lockout: shorted or open return temperature sensor pro repair	shorted or mis-wired return sensor wiring; defective return sensor	a single reset may be attempted; this needs sensor diagnosis by a licensed technician
Soft Lockout 8	Soft lockout: shorted or open supply temperature sensor pro repair	shorted or mis-wired supply sensor wiring; defective supply sensor	a single reset may be attempted; this needs sensor diagnosis by a licensed technician
Soft Lockout 9	Soft lockout: shorted or open Domestic Hot Water (DHW) temperature sensor pro repair	shorted or mis-wired DHW sensor wiring; defective DHW sensor	a single reset may be attempted; this needs sensor diagnosis by a licensed technician
Soft Lockout 10	Soft lockout: shorted or open flue gas (stack) temperature sensor pro repair	shorted or mis-wired flue/stack temperature sensor wiring; defective flue/stack sensor	a single reset may be attempted; this needs sensor diagnosis by a licensed technician
Soft Lockout 11	Soft lockout: ignition failure – flame failure after 5 tries to restart (flame rod not detecting flame) pro repair	no gas, gas line not purged of air, or gas pressure below the rating-plate minimum; plugged condensate trap or plugged drain line in the trap; defective electrode, ignition cable or flame rod	confirm the gas supply is on and other gas appliances work; check the condensate drain/trap is not blocked or frozen; try a single reset (do not reset repeatedly)
Soft Lockout 13	Soft lockout: flame rod shorted to ground pro repair	shorted or mis-wired flame rod wiring; defective flame rod; plugged condensate trap or drain line in the trap	check the condensate drain/trap is not blocked; a single reset may be attempted; this needs a licensed technician if it recurs
Soft Lockout 14	Soft lockout: temperature rise between supply and return is too high (differential inlet/outlet high) pro repair	inadequate boiler water flow (circulator not operating, or circulator/piping undersized); flow through the boiler reversed (incorrect piping or circulator orientation); air not purged from the system	check the system pressure gauge and top up if low per the user manual; ensure system/radiator isolation valves are open; if it recurs, call a licensed technician
Soft Lockout 15	Soft lockout: control is reading a return sensor temperature higher than the supply sensor temperature (present at least ~75 seconds) pro repair	no or insufficient boiler water flow (air not purged, valves closed); supply/return sensor wiring reversed; defective supply or return sensor	check the system pressure gauge and top up if low per the user manual; ensure system/radiator valves are open; if it recurs, call a licensed technician
Soft Lockout 16	Soft lockout: supply water temperature has risen too quickly pro repair	inadequate boiler water flow; circulator not operating or circulator/piping undersized	check the system pressure gauge and top up if low per the user manual; ensure system/radiator valves are open; if it recurs, call a licensed technician
Soft Lockout 17	Soft lockout (normal): waiting for blower/fan speed to match the purge and light-off setpoint pro repair	normal operation – the control is waiting for the blower to reach the correct purge/light-off speed	no action needed – this is part of the normal start sequence; if the boiler never fires, call a licensed technician
Soft Lockout 27	Soft lockout: undefined fault pro repair	internal control condition not otherwise defined	a single reset may be attempted; if it recurs, a licensed technician should consult the factory
Soft Lockout 28	Soft lockout: Air Proving Switch failed to close (also reported as 53) pro repair	blocked vent or air intake, blocked or disconnected air-switch tube; blocked heat exchanger or burner; defective air proving switch or loose switch wiring	check the outside vent/air-intake terminal for visible obstruction from a safe position; do not dismantle the flue or switch; call a licensed technician; a single reset may be attempted
Soft Lockout 53	Soft lockout: Air Proving Switch failed to close (same condition as code 28) pro repair	blocked vent or air intake, blocked or disconnected air-switch tube; blocked heat exchanger or burner; defective air proving switch or loose switch wiring	check the outside vent/air-intake terminal for visible obstruction from a safe position; do not dismantle the flue or switch; call a licensed technician; a single reset may be attempted
Soft Lockout 54	Soft lockout: Air Proving Switch failed to open (air switch closed when it should be open before the blower starts; leads to a manual-reset hard lockout) pro repair	air proving switch jumpered; defective air proving switch; blower running before the start sequence (loss of communication between blower and control – defective harness, blower or control)	no homeowner-safe internal action; a single reset may be attempted; this requires a licensed technician
Hard Lockout 4	Hard lockout: Supply High Limit – control supply sensor detected temperatures in excess of 210F pro repair	heating load far below the boiler's minimum firing rate; defective system circulator or no flow in the primary loop; defective boiler circulator or no/insufficient flow in the boiler loop	check the system pressure gauge and top up if low per the user manual; ensure system/radiator valves are open so water can circulate; perform a single manual reset after the boiler cools; if it recurs, call a licensed technician
Hard Lockout 5	Hard lockout: DHW high limit – control DHW sensor detected temperatures in excess of setpoint pro repair	DHW sensor or wiring fault; DHW overheating condition	perform a single manual reset; if it recurs, call a licensed technician
Hard Lockout 6	Hard lockout: Stack High Limit – control flue gas (stack) sensor detected temperatures over limit (about 204F on early Alpine; 214F / 101C on K2 and Aspen) pro repair	heat exchanger needs to be cleaned; boiler over-fired; air-fuel mixture out of adjustment	perform a single manual reset after the boiler cools; this requires combustion service by a licensed technician if it recurs
Hard Lockout 12	Hard lockout: flame detected out of sequence – a flame signal was present when there should be no flame pro repair	defective gas valve (verify inlet pressure is below the rating-plate maximum before replacing); plugged condensate trap or plugged drain line in the trap	confirm the gas supply is on and other gas appliances work; check the condensate drain/trap is not blocked; do not open the gas valve; this requires a licensed technician
Hard Lockout 18	Hard lockout: Light-off rate proving failed – blower not running at light-off rate, or blower speed signal not detected by the control pro repair	loose connection in the 120 VAC blower wiring; loose or mis-wired blower speed harness; defective blower	no homeowner-safe internal action; a single manual reset may be attempted; this requires a licensed technician
Hard Lockout 19	Hard lockout: Purge rate proving failed – blower not running at purge rate, or blower speed signal not detected by the control pro repair	loose connection in the 120 VAC blower wiring; loose or mis-wired blower speed harness; defective blower	no homeowner-safe internal action; a single manual reset may be attempted; this requires a licensed technician
Hard Lockout 20	Hard lockout: invalid safety parameters – unacceptable control safety-related parameter detected pro repair	safety parameter verification required after a control change; internal control issue	no homeowner-safe action; this requires a licensed technician (often a factory consult)
Hard Lockout 21	Hard lockout: invalid modulation parameter – unacceptable control modulation-related parameter detected pro repair	control modulation parameter fault	a single reset may be attempted; if it recurs, call a licensed technician
Hard Lockout 22	Hard lockout: safety data verification needed – a safety-related parameter change was detected and verification has not been completed pro repair	a safety-related control parameter was changed and verification was not performed	no homeowner-safe action; this requires a licensed technician to verify parameters
Hard Lockout 23	Hard lockout: 24VAC control power high or low pro repair	loose connection or mis-wired 24VAC power harness; mis-wired harness causing a power-supply short to ground; defective transformer, or transformer frequency/voltage/VA not to spec	no homeowner-safe internal action; this requires a licensed technician
Hard Lockout 24	Hard lockout: Fuel Valve Error – power detected at the fuel valve output when the fuel valve should be off pro repair	control or wiring fault at the fuel valve output	a single reset may be attempted; if it recurs, the control likely needs replacement by a licensed technician
Hard Lockout 25	Hard lockout: Hardware Fault – internal control failure pro repair	internal Sage control hardware fault	a single reset may be attempted; if it recurs, the control needs replacement by a licensed technician
Hard Lockout 26	Hard lockout: Internal Fault – internal control failure pro repair	internal Sage control fault	a single reset may be attempted; if it recurs, the control needs replacement by a licensed technician
Hard Lockout 27	Hard lockout: undefined fault pro repair	internal control condition not otherwise defined	a single reset may be attempted; if it recurs, the control may need replacement by a licensed technician
Hard Lockout 54	Hard lockout: Air Proving Switch failed to open (manual-reset result of the air-switch-closed condition; see Soft Lockout 54) pro repair	air proving switch jumpered or defective; blower running before the start sequence due to loss of communication with the control	no homeowner-safe internal action; a single manual reset may be attempted; this requires a licensed technician
Err 2	ESC (IQ Control): Pressure Switch Failed to Open – while the blower is off the pressure switch contact is stuck closed pro repair	kinked or blocked pressure switch tubing; defective pressure switch; wiring fault	no homeowner-safe internal action; this requires a licensed technician
Err 4	ESC (IQ Control): Flame Current Lower than Threshold pro repair	pilot/flame sensing problem; dirty or misaligned pilot assembly	confirm the gas supply is on and other gas appliances work; this requires a licensed technician
Err 6	ESC (IQ Control): Flame Sensed Out of Normal Sequence (flame sensed before the gas valve opens or after it closes) pro repair	gas valve not closing/operating correctly; flame-sensing fault	confirm the gas supply is on; do not open the gas valve; this requires a licensed technician
Err 18	ESC (IQ Control): Electronics Failure pro repair	internal IQ control electronics fault; wiring fault	cycle power to the control (single power reset); if it recurs, the control needs a licensed technician
Err 23	ESC (IQ Control): Flame Sensed During Pre-Purge (flame sensed before the gas valve is signaled open) pro repair	gas valve not closing/leaking by; flame-sensing fault	confirm the gas supply is on; do not open the gas valve; this requires a licensed technician
Err 29	ESC (IQ Control): Pressure Switch Failed to Close – while the blower is on the pressure switch did not close pro repair	blockage in the vent or air-intake system; tubing not connected / cracked / holding condensate; vent not installed per the manual or excessive wind (>40 mph) at a horizontal terminal	check the outside vent/air-intake terminal for visible obstruction from a safe position; do not dismantle the vent or switch; this requires a licensed technician
Err 32	ESC (IQ Control): Temperature Sensor Failure (open/short, high resistance, dual-sensor mismatch, or control hardware failure) pro repair	temperature sensor or interface failure; control hardware failure	a single power reset may be attempted; this requires a licensed technician
Err 35	ESC (IQ Control): Duplicate Zone Alarm pro repair	zone configuration conflict (refer to the IQ Zone Panel instructions)	no homeowner-safe action; this requires a licensed technician
Err 57	ESC (IQ Control): Flame Rod Shorted to Burner Ground (can result from excessive flue-gas condensation) pro repair	excessive condensate / dry pilot; loose or damaged ignition wire	no homeowner-safe internal action; this requires a licensed technician
Err 58	ESC (IQ Control): AC Line Frequency Error – AC signal too noisy or frequency incorrect pro repair	noisy or out-of-spec mains supply	no homeowner-safe action; have the supply voltage checked by a licensed technician
Err 59	ESC (IQ Control): Line Voltage Error – AC voltage out of specification (high or low) pro repair	mains supply voltage too high or too low	confirm the boiler breaker is on; no homeowner-safe internal action; this requires a licensed technician
Err 60	ESC (IQ Control): Thermostat Input Higher than Threshold pro repair	thermostat wiring fault	no homeowner-safe internal action; this requires a licensed technician
Err 61	ESC (IQ Control): Line Voltage Unstable (erratic supply voltage, possibly from heavy loads switching on and off) pro repair	unstable mains supply voltage	no homeowner-safe action; have the supply voltage checked by a licensed technician
Err 63	ESC (IQ Control): Soft Lockout – Maximum Recycles Exceeded pro repair	repeated ignition recycles exceeded the allowed maximum (often a pilot/ignition issue)	confirm the gas supply is on and other gas appliances work; a single reset may be attempted; if it recurs, this requires a licensed technician
Err 64	ESC (IQ Control): Soft Lockout – Internal Failure (electronics detected an internal or wiring fault) pro repair	actual controller internal fault or a wiring fault; pilot assembly problem	a single reset may be attempted; if it recurs, the control needs a licensed technician
Err 89	ESC (IQ Control): Communication Lost pro repair	wiring fault between the control and the IQ Zone Panel or IQ Reset Card	no homeowner-safe internal action; this requires a licensed technician

Burnham boiler codes we get called for most

Soft Lockout 11 — Soft lockout: ignition failure – flame failure after 5 tries to restart (flame rod not detecting flame)

Typical causes include no gas, gas line not purged of air, or gas pressure below the rating-plate minimum; plugged condensate trap or plugged drain line in the trap; defective electrode, ignition cable or flame rod. A few things are safe to check yourself (confirm the gas supply is on and other gas appliances work; check the condensate drain/trap is not blocked or frozen), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes Soft Lockout 11 on Burnham boilers throughout Greater Vancouver.

Err 2 — ESC (IQ Control): Pressure Switch Failed to Open – while the blower is off the pressure switch contact is stuck closed

Typical causes include kinked or blocked pressure switch tubing; defective pressure switch; wiring fault. A few things are safe to check yourself (no homeowner-safe internal action; this requires a licensed technician), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes Err 2 on Burnham boilers throughout Greater Vancouver.

Soft Lockout 14 — Soft lockout: temperature rise between supply and return is too high (differential inlet/outlet high)

Typical causes include inadequate boiler water flow (circulator not operating, or circulator/piping undersized); flow through the boiler reversed (incorrect piping or circulator orientation); air not purged from the system. A few things are safe to check yourself (check the system pressure gauge and top up if low per the user manual; ensure system/radiator isolation valves are open), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes Soft Lockout 14 on Burnham boilers throughout Greater Vancouver.

Soft Lockout 17 — Soft lockout (normal): waiting for blower/fan speed to match the purge and light-off setpoint

Typical causes include normal operation – the control is waiting for the blower to reach the correct purge/light-off speed. A few things are safe to check yourself (no action needed – this is part of the normal start sequence; if the boiler never fires, call a licensed technician), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes Soft Lockout 17 on Burnham boilers throughout Greater Vancouver.

Is it safe to keep running a Burnham boiler with a fault code?

Most Burnham 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.

Burnham boiler repair across Greater Vancouver

HeatLand has kept Metro Vancouver homes comfortable since 1999. Our licensed, insured technicians diagnose and repair Burnham 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.

Burnham boiler service areas

We repair Burnham boilers across Greater Vancouver and the Fraser Valley, including:

Burnham boiler error code FAQs

Can I reset my Burnham 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 Burnham Soft Lockout 7 code mean?

On Burnham boilers, Soft Lockout 7 commonly indicates soft lockout: shorted or open return temperature sensor. 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 Burnham boilers you didn’t install?

Yes. HeatLand is brand-agnostic and services Burnham 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 Burnham 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 Burnham boiler repair cost in Vancouver?

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

More Boiler error-code guides

HeatLand repairs every major boiler brand across Greater Vancouver. More brand guides: