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

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

The codes below apply across common Triangle Tube models (Prestige (Solo / Excellence / Trimax), Challenger). Meanings follow Triangle Tube’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 Triangle Tube boiler error codes

Triangle Tube boilers using the MCBA / Trimax-ACVMax control show two classes of fault on the display. A SOFT lockout (auto-recovering) alternates a leading 'b' with a two-digit number (e.g. b18, b30) — on Prestige the display flashes between '9 + outlet temp' and 'b + code'. A HARD lockout (requires manual RESET) shows a leading 'E' followed by a two-digit code (e.g. E02, E04, E52). On Challenger-series controls the hard-lockout code is shown as E followed by a number (e.g. E4, E10). Codes below are taken from Triangle Tube's official Prestige Service Technician's Troubleshooting Guide (2008-36 TSG-PRESTIGE) and the Challenger Installation & Maintenance Manual.

Triangle Tube boiler error codes & what they mean

These are the Triangle Tube 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
E00	Flame detected prior to burner startup (false flame signal / flame present when none expected) pro repair	Faulty flame sensor or ignition/flame circuit; Control module fault; Residual flame signal	Confirm the boiler is in lockout and note the code; Press RESET once
E02	Gas valve harness not properly connected pro repair	Loose or disconnected gas valve wiring harness; Damaged harness/connector	Confirm the boiler has power and gas supply is on; Press RESET once
E03	Failed ignition after 5 attempts (burner failed to light) pro repair	Gas supply off or low gas pressure; Igniter, flame sensor, or gas valve fault; Air in gas line / blocked flue or intake	Confirm the gas shutoff valve to the boiler is open; Confirm other gas appliances work (indicates gas supply present); Check the condensate drain/trap is not blocked
E04	Power supply lost after a lockout occurred pro repair	Power was cycled while the boiler was already in lockout; Intermittent power supply	Confirm steady power to the boiler (breaker on, switch on); Press RESET once to clear
E05	Internal control failure pro repair	Control module (MCBA) internal fault	Note the code; Press RESET once
E06	Internal control failure pro repair	Control module (MCBA) internal fault	Note the code; Press RESET once
E07	Internal control failure pro repair	Control module (MCBA) internal fault	Note the code; Press RESET once
E08	Internal control failure pro repair	Control module (MCBA) internal fault	Note the code; Press RESET once
E09	Internal control failure pro repair	Control module (MCBA) internal fault	Note the code; Press RESET once
E11	Internal control failure pro repair	Control module (MCBA) internal fault	Note the code; Press RESET once
E12	External limit (terminals 13 & 14) is OPEN pro repair	External limit control / safety device has tripped or is open; Wiring fault on the external limit circuit; Low system water condition tied to that limit	Read the system pressure gauge (typical cold fill ~12 psi); report if abnormally low; Press RESET once
E15	Blower (fan) signal does not reset to zero pro repair	Blower / fan feedback fault; Wiring to blower; Control module fault	Note the code; Press RESET once
E16	No blower (fan) signal present pro repair	Blower not running or no speed feedback; Blower power/wiring fault; Seized or failed blower	Note the code; Press RESET once
E28	Supply (outlet) temperature sensor is short-circuited pro repair	Failed supply temperature sensor; Pinched/shorted sensor wiring	Note the code; Press RESET once
E29	Supply (outlet) temperature sensor fault / open circuit pro repair	Open or disconnected supply temperature sensor; Sensor wiring fault	Note the code; Press RESET once
E52	Flue temperature exceeds 250 F pro repair	Excessive flue temperature; Scaled / dirty heat exchanger; Restricted flow / low water flow through boiler	Confirm heating system has adequate water pressure (read gauge); Press RESET once
E61	Internal control error – failure to read parameters pro repair	Control module parameter memory fault; Control module failure	Note the code; Press RESET once
b18	Soft lockout: Supply temperature too high (~202 F). Burner stays OFF until temperature drops below ~200 F, then auto-resumes pro repair	Low water flow through the boiler; Air-bound system or stuck circulator; Closed isolation valves	Read the system pressure gauge and report if low; Confirm the heating circulator/zone is calling and nothing is obviously off; Allow time to cool — it may auto-clear
b19	Soft lockout: Return temperature too high (~202 F). Burner stays OFF until temperature drops below ~200 F pro repair	Low flow / circulation problem; Air in system; Low system pressure	Read the system pressure gauge and report if low; Allow the boiler to cool — it may auto-clear
b24	Soft lockout: Return temperature is higher than supply temperature. Burner stays OFF until corrected pro repair	Supply/return sensors swapped; Circulator wired for wrong flow direction; Reverse flow / piping issue	Note the code for the technician
b25	Soft lockout: Supply temperature increased too quickly. Burner stays OFF ~10 minutes, then recycles (waiting period increases by 1 min, up to ~15 min) pro repair	Low water flow / air in heat exchanger; Stuck or undersized circulator; Closed valves	Read the system pressure gauge and report if low; Allow time — it auto-recycles
b26	Soft lockout: Factory-supplied low-water-cutoff (LWCO) device or external limit (terminals 15 & 16) is OPEN. Burner off ~150 seconds, auto reset pro repair	Low water level / low system pressure tripping the LWCO; External limit open; LWCO or wiring fault	Read the system pressure gauge — low pressure can trip the low-water cutoff; report the reading; Wait for auto-reset
b28	Soft lockout: No blower signal pro repair	Blower not reporting speed; Blower or wiring fault	Note the code
b29	Soft lockout: Blower signal present with no demand. Burner stays OFF until condition terminates pro repair	Blower feedback fault; Control / wiring issue	Note the code
b30	Soft lockout: Temperature difference between supply and return is more than ~72 F. Burner off ~150 seconds, then recycles (up to ~20 cycles) pro repair	Low water flow / circulation fault; Air-bound system; Partially closed valves	Read the system pressure gauge and report if low; Allow time — it auto-recycles
b33	Soft lockout: Flue temperature sensor is short-circuited. Burner OFF until corrected pro repair	Failed flue sensor; Shorted sensor wiring	Note the code
b35	Soft lockout: Flue temperature sensor is 'open'. Burner OFF until corrected pro repair	Open/disconnected flue sensor; Sensor wiring fault	Note the code
b38	Soft lockout: Flue temperature greater than 240 F but less than 250 F. Burner off ~150 seconds pro repair	High flue temperature; Scaled/dirty heat exchanger; Low flow	Read the system pressure gauge and report if low; Allow time — it may auto-clear
b40	Soft lockout: Wait for the blower to start (boiler waiting on blower) pro repair	Normal transient, or slow/failing blower start; Blower wiring	Allow the boiler a moment to start the fan
b52	Soft lockout: Indirect (DHW) water heater temperature sensor is short-circuited. Burner OFF until corrected pro repair	Failed indirect tank sensor; Shorted sensor wiring	Note the code
b65	Soft lockout: Indirect (DHW) water heater temperature sensor is 'open' or disconnected. Burner OFF until corrected pro repair	Open/disconnected indirect tank sensor; Sensor wiring fault	Note the code
b116	Soft lockout: Power frequency deviation (line frequency out of range) pro repair	Unstable/poor incoming power; Generator or inverter power with off-spec frequency	Confirm the boiler is on stable utility power (not a generator)
b181	Soft lockout: Flame current signal lost pro repair	Weak/dirty flame sensor; Marginal gas pressure; Grounding issue	Confirm gas supply is on (other gas appliances work); Allow the boiler to recycle
E0	Sensor fault after self-check pro repair	Sensor or control self-check failure	Note the code; Press RESET once
E1 / E28	Temperature too high pro repair	Low water flow / circulation fault; Air-bound system; Low system pressure	Read the system pressure gauge and report if low; Allow the boiler to cool; Press RESET once
E2	CH supply sensor (S1) and CH return sensor (S2) interchanged (swapped) pro repair	Supply and return sensors connected to wrong terminals; Reverse flow piping/wiring	Note the code
E4	No flame signal (burner failed to light) pro repair	Gas supply off or low gas pressure; Igniter / flame sensor / gas valve fault; Blocked flue, intake, or condensate trap	Confirm the gas shutoff valve is open and other gas appliances work; Check the condensate drain/trap is not blocked; Confirm steady power
E5	Poor flame signal pro repair	Dirty/weak flame sensor; Marginal gas pressure; Grounding / flame-rod fault	Confirm gas supply is on; Press RESET once
E6	Flame detection fault pro repair	Flame-sensing circuit fault; Control module fault; False flame signal	Note the code; Press RESET once
E8	Incorrect fan (blower) speed pro repair	Blower fault or wrong speed feedback; Blocked flue/intake affecting fan; Blower wiring fault	Note the code; Press RESET once
E10-E14	CH supply sensor (S1) fault (open, shorted, or implausible reading) pro repair	Failed supply temperature sensor; Sensor wiring open or shorted	Note the code; Press RESET once
E16 / E17 / E7	DHW (domestic hot water) sensor fault pro repair	Failed DHW sensor; Open or shorted DHW sensor wiring	Note the code; Press RESET once
E18 / E19	Flue sensor fault pro repair	Failed flue temperature sensor; Open or shorted flue sensor wiring	Note the code; Press RESET once
E20-E24	CH return sensor (S2) fault (open, shorted, or implausible reading) pro repair	Failed return temperature sensor; Sensor wiring open or shorted	Note the code; Press RESET once
E29 / E30	Gas valve relay fault pro repair	Gas valve relay / control fault; Gas valve wiring fault	Note the code; Press RESET once
50F	Improper power frequency (line frequency out of range) pro repair	Unstable incoming power; Generator/inverter power off-spec	Confirm the boiler is on stable utility power

Triangle Tube boiler codes we get called for most

E03 — Failed ignition after 5 attempts (burner failed to light)

Typical causes include gas supply off or low gas pressure; igniter, flame sensor, or gas valve fault; air in gas line / blocked flue or intake. A few things are safe to check yourself (Confirm the gas shutoff valve to the boiler is open; Confirm other gas appliances work (indicates gas supply present)), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes E03 on Triangle Tube boilers throughout Greater Vancouver.

b18 — Soft lockout: Supply temperature too high (~202 F). Burner stays OFF until temperature drops below ~200 F, then auto-resumes

Typical causes include low water flow through the boiler; air-bound system or stuck circulator; closed isolation valves. A few things are safe to check yourself (Read the system pressure gauge and report if low; Confirm the heating circulator/zone is calling and nothing is obviously off), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes b18 on Triangle Tube boilers throughout Greater Vancouver.

E15 — Blower (fan) signal does not reset to zero

Typical causes include blower / fan feedback fault; wiring to blower; control module fault. A few things are safe to check yourself (Note the code; Press RESET once), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes E15 on Triangle Tube boilers throughout Greater Vancouver.

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

Most Triangle Tube 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.

Triangle Tube boiler repair across Greater Vancouver

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

Triangle Tube boiler service areas

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

Triangle Tube boiler error code FAQs

Can I reset my Triangle Tube 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 Triangle Tube E03 code mean?

On Triangle Tube boilers, E03 commonly indicates failed ignition after 5 attempts (burner failed to light). 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 Triangle Tube boilers you didn’t install?

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

It depends on the fault. Many Triangle Tube 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

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