John Wood Water Heater Error Codes — Meanings, Causes & Repair in Greater Vancouver

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

The codes below apply across common John Wood models (Atmospheric/Standing Pilot (thermopile gas control), Power Vent, Power Direct Vent, Eco-Hybrid). Meanings follow John Wood’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 John Wood water heater error codes

Blinking status LED (gas control diagnostic light). Two distinct John Wood / GSW / Giant gas-control systems exist: (1) STANDING-PILOT atmospheric models use a thermopile-powered Honeywell gas control with a simple count: 0 / solid / 1 / 2 / 4 / 5 / 7 flashes. (2) POWER-VENT and POWER-DIRECT-VENT models use a 120V electronic Honeywell control with a hot-surface igniter and a richer flash sequence (e.g. 'four flash, three-second pause', or compound codes like 'six-two flash' = six flashes, brief gap, two flashes). On power-vent controls 1 short flash every ~3-4 seconds = normal/idle and a bright/dim 'heartbeat' = call for heat. Read the count, then the 3-second pause repeats it. Older Intelli-Vent power-direct-vent models (e.g. 4040SN-PDV) instead show a two-digit 'Error 7-13' number rather than blinks. ALWAYS match the chart on the unit's own gas-control label, as codes differ between the two systems.

John Wood water heater error codes & what they mean

These are the John Wood water heater 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
1 flash every 3 seconds (standing-pilot) / short flash once every 4 sec (power-vent)	Normal operation / IDLE. Pilot is lit (or, on power-vent, no call for heat) and the control is working properly with no fault conditions DIY-checkable	Normal running state – no fault	Confirm you have hot water; no action needed if heating normally; Confirm the gas control / status light is blinking this normal pattern
Heartbeat (LED alternates bright/dim)	Power-vent control only: Call For Heat in progress, no fault conditions. The unit is responding to a demand for hot water DIY-checkable	Normal – thermostat is calling for heat	No action needed; this is a normal running indication
0 flashes / LED not lit	Standing-pilot models: pilot light is not lit, OR the thermopile has not yet reached normal operating temperature (it can take up to ~90 seconds after lighting the pilot for the light to begin blinking) DIY-checkable	Pilot is out; Pilot just lit – thermopile still warming up; No gas supply to pilot	Confirm the main gas supply valve is ON; Look through the viewport to see if the pilot flame is lit; If pilot is out, follow the single lighting procedure printed on the unit's label
Solid / LED on continuously (standing-pilot)	Standing-pilot models: pilot light was recently extinguished and the thermopile is cooling down DIY-checkable	Pilot recently went out; Thermopile still hot and cooling	Wait ~10 minutes for the gas control to clear, then relight the pilot using the procedure on the unit's label (single relight attempt); Confirm the main gas supply is ON
2 flashes	Pilot is lit but the thermopile is not producing the required output voltage (standing-pilot). On power-vent controls a 'Two Flash, three-second pause' indicates Pressure Switch Failed Closed pro repair	Weak / failing thermopile (standing-pilot); Loose or dirty thermopile connection at the gas control (standing-pilot); Pilot flame too small / partially blocked pilot	Standing-pilot: confirm the pilot flame is present and steady through the viewport; Try one single relight per the on-unit label after waiting; If it persists, stop and call a licensed gas technician
One Flash, three-second pause (power-vent)	Power-vent control: Low Flame Signal. The control continues to operate but is sensing a weak flame pro repair	Weak flame sense signal; Dirty / cracked flame sensor rod; Partially blocked burner or marginal gas pressure	Note the code and monitor whether the unit still heats; Do not open the burner or sealed combustion area – call a licensed technician for sensor/flame service
Two Flash, three-second pause (power-vent)	Power-vent control: Pressure Switch Failed Closed – the vent/air pressure switch is showing closed when it should be open pro repair	Pressure switch stuck closed; Pressure switch hose/wiring fault; Vent/blower condition affecting the switch	Confirm the unit is plugged in and has power (check breaker); Do a single power cycle: turn the unit OFF for 10 seconds, then ON; If it returns, call a licensed technician
Three Flash, three-second pause (power-vent)	Power-vent control: Pressure Switch Failed Open – insufficient draft/airflow is being proven, or the pressure switch is stuck open pro repair	Blocked or restricted vent piping; Blower not running or weak blower; Kinked / disconnected pressure switch hose	Confirm the unit has power and is plugged in (check breaker); Check that the outdoor vent termination is not blocked, iced, or covered (do NOT disassemble vent piping); Single power cycle OFF 10 sec then ON
4 flashes (standing-pilot) / Four Flash, three-second pause (power-vent)	Over-temperature shutdown. ECO / TCO (Energy Cut Off) limit lockout – the gas control's temperature sensor detected the water temperature exceeded the safe limit, and the main burner (and pilot, on standing-pilot) has been shut off pro repair	Thermostat set too high; Gas control valve / thermostat fault holding the burner on; Sediment causing localized overheating	Confirm the temperature dial is not set excessively high; lower it to a normal setting; If the 4-flash code recurs after a single restart, turn the main gas supply OFF and call a licensed technician (manual specifies the gas control/thermostat should be replaced by a qualified tech)
5 flashes (standing-pilot) / Five Flash, three-second pause (power-vent)	Standing-pilot: the temperature sensor (thermistor) is defective. Power-vent: Flame Out Of Sequence – flame was sensed at the wrong time in the ignition cycle pro repair	Defective temperature sensor / thermistor (standing-pilot); Power-vent: cracked flame-sensor ceramic insulator, stray flame signal, or control fault	Try one single power cycle (power-vent) per the on-unit instructions; This is a control/sensor fault – call a licensed technician for diagnosis or replacement
Six-One Flash, three-second pause (power-vent)	Power-vent control: Soft Lockout – Retry Limit reached / Failed Trial For Ignition. The unit tried to light, failed repeatedly, and locked out pro repair	No gas / gas valve off / air in gas line; Failed hot-surface igniter; Weak or no flame sense	Confirm the main gas supply valve is ON; Confirm other gas appliances work (rules out a supply outage); Single reset: turn unit OFF 10 sec, then ON, to allow one retry
Six-Two Flash, three-second pause (power-vent)	Power-vent control: Soft Lockout – Recycle Limit reached because the pressure switch / high limit opened during operation pro repair	Intermittent vent/draft problem opening the pressure switch; High-limit tripping due to overheating; Pressure switch hose/wiring fault	Confirm the vent termination outside is clear; Confirm unit has power (breaker); Single power cycle OFF 10 sec then ON
Six-Three Flash, three-second pause (power-vent)	Power-vent control: Soft Lockout – Recycle Limit reached because the flame was lost during a heating cycle pro repair	Flame dropping out mid-cycle (gas supply fluctuation / low pressure); Dirty or failing flame sensor; Burner / orifice problem	Confirm the main gas supply is ON; Single power cycle OFF 10 sec then ON; If it returns, call a licensed technician (do not open the sealed burner)
Six-Four Flash, three-second pause (power-vent)	Power-vent control: Soft Lockout – Flame Out Of Sequence sensed (flame detected when none should be present) pro repair	Stray flame signal; Cracked flame-sensor insulator; Gas valve not closing fully / control fault	Single power cycle OFF 10 sec then ON; This indicates a possible gas-valve or sensor fault – call a licensed technician
7 flashes (standing-pilot)	Standing-pilot models: gas control valve failure pro repair	Internal gas control valve / thermostat failure	No safe homeowner fix – the gas control valve must be replaced by a qualified gas technician; Turn the main gas supply OFF if you smell gas and call a technician
Seven Flash, three-second pause (power-vent)	Power-vent control: Flammable Vapour Sensor (FVS) Lockout – the FVR sensor has detected flammable vapours and locked the unit out. Lockout is indefinite until reset per the manual pro repair	Flammable vapours near the heater (gasoline, solvents, adhesives, paint); Failed flammable vapour sensor	Remove and store any gasoline, solvents, paints or other flammable liquids away from the water heater and ventilate the area; Do NOT attempt to defeat or bypass the sensor; Reset only per the on-unit instructions; if it relocks, call a licensed technician immediately
Eight-One Flash, three-second pause (power-vent)	Power-vent control: Flammable Vapour Sensor (FVS) Fault Detected (sensor circuit fault, distinct from a vapour lockout) pro repair	Faulty / disconnected flammable vapour sensor; Sensor wiring fault	Confirm there are no flammable liquids stored near the unit; Single power cycle OFF 10 sec then ON; If it persists, call a licensed technician – the sensor/control may need replacement
Eight-Two Flash, three-second pause (power-vent)	Power-vent control: Temperature Sensor Fault Detected – the water temperature sensor is open or short-circuited pro repair	Open or shorted temperature sensor; Sensor wiring fault; Control board fault	Single power cycle OFF 10 sec then ON; If it returns, call a licensed technician (sensor/control replacement)
Eight-Three Flash, three-second pause (power-vent)	Power-vent control: Electronics Fault Detected – an internal control electronics/microcomputer fault pro repair	Internal control board / microcomputer fault	Single power cycle OFF 10 sec then ON; If the code returns, the gas control must be replaced by a licensed technician
Eight-Four Flash, three-second pause (power-vent)	Power-vent control: Valve Fault Detected – a fault in the gas valve driver circuit / gas valve pro repair	Gas valve driver circuit fault; Gas valve fault	Single power cycle OFF 10 sec then ON; If unresolved, the gas control valve must be replaced by a licensed technician
LED continuously ON / Hardware (Hard) Fault Lockout (power-vent)	Power-vent control: Hard Lockout / Hardware Fault. The main controller has failed and must be replaced. Lockout is indefinite pro repair	Failed main control board	No homeowner fix – the control/gas valve must be replaced by a licensed technician; Turn the main gas supply OFF if you smell gas and call a technician
Error 7 (Intelli-Vent power-direct-vent, e.g. 4040SN-PDV)	Older Intelli-Vent power-direct-vent control: a problem with the gas valve driver circuit pro repair	Gas valve driver circuit fault; Control board fault	Single power cycle: turn power OFF for ~10 seconds then ON; If the error remains, the control must be replaced by a licensed technician
Error 8 (Intelli-Vent power-direct-vent)	Older Intelli-Vent control: a problem with the internal microcomputer pro repair	Internal microcomputer fault	Single power cycle OFF ~10 seconds then ON; If it persists, replace control – call a licensed technician
Error 9 (Intelli-Vent power-direct-vent)	Older Intelli-Vent control: a problem with the internal circuit pro repair	Internal control circuit fault	Single power cycle OFF ~10 seconds then ON; If it persists, call a licensed technician
Error 10 (Intelli-Vent power-direct-vent)	Older Intelli-Vent control: flame signal sensed out of proper sequence pro repair	Cracked flame-sensor ceramic insulator; Stray flame signal; Control fault	Single power cycle OFF ~10-20 seconds then ON; If it returns, call a licensed technician (flame sensor / control)
Error 11 (Intelli-Vent power-direct-vent)	Older Intelli-Vent control: the high-temperature thermal cutoff is open (over-temperature safety has tripped) pro repair	High-limit / thermal cutoff opened due to overheating; Sediment / stacking; Defective high-limit switch	Lower the temperature dial to a normal setting; Single power cycle OFF ~10-20 seconds then ON; If it recurs, turn the main gas supply OFF and call a licensed technician
Error 12 (Intelli-Vent power-direct-vent)	Older Intelli-Vent control: one of the temperature-adjust buttons is stuck closed pro repair	Stuck temperature-adjust button; Obstruction on the control panel	Remove any obstruction from the control panel buttons and press them lightly to free them; If it persists, call a licensed technician
Error 13 (Intelli-Vent power-direct-vent)	Older Intelli-Vent control: the water temperature sensor is open or short-circuited pro repair	Open or shorted water temperature sensor; Sensor wiring fault	Single power cycle OFF ~10-20 seconds then ON; If it returns, call a licensed technician (sensor/wiring/control)

John Wood water heater codes we get called for most

5 flashes (standing-pilot) / Five Flash, three-second pause (power-vent) — Standing-pilot: the temperature sensor (thermistor) is defective. Power-vent: Flame Out Of Sequence – flame was sensed at the wrong time in the ignition cycle

Typical causes include defective temperature sensor / thermistor (standing-pilot); power-vent: cracked flame-sensor ceramic insulator, stray flame signal, or control fault. A few things are safe to check yourself (Try one single power cycle (power-vent) per the on-unit instructions; This is a control/sensor fault – call a licensed technician for diagnosis or replacement), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes 5 flashes (standing-pilot) / Five Flash, three-second pause (power-vent) on John Wood water heaters throughout Greater Vancouver.

Six-Three Flash, three-second pause (power-vent) — Power-vent control: Soft Lockout – Recycle Limit reached because the flame was lost during a heating cycle

Typical causes include flame dropping out mid-cycle (gas supply fluctuation / low pressure); dirty or failing flame sensor; burner / orifice problem. A few things are safe to check yourself (Confirm the main gas supply is ON; Single power cycle OFF 10 sec then ON), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes Six-Three Flash, three-second pause (power-vent) on John Wood water heaters throughout Greater Vancouver.

2 flashes — Pilot is lit but the thermopile is not producing the required output voltage (standing-pilot). On power-vent controls a 'Two Flash, three-second pause' indicates Pressure Switch Failed Closed

Typical causes include weak / failing thermopile (standing-pilot); loose or dirty thermopile connection at the gas control (standing-pilot); pilot flame too small / partially blocked pilot. A few things are safe to check yourself (Standing-pilot: confirm the pilot flame is present and steady through the viewport; Try one single relight per the on-unit label after waiting), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes 2 flashes on John Wood water heaters throughout Greater Vancouver.

4 flashes (standing-pilot) / Four Flash, three-second pause (power-vent) — Over-temperature shutdown. ECO / TCO (Energy Cut Off) limit lockout – the gas control's temperature sensor detected the water temperature exceeded the safe limit, and the main burner (and pilot, on standing-pilot) has been shut off

Typical causes include thermostat set too high; gas control valve / thermostat fault holding the burner on; sediment causing localized overheating. A few things are safe to check yourself (Confirm the temperature dial is not set excessively high; lower it to a normal setting; If the 4-flash code recurs after a single restart, turn the main gas supply OFF and call a licensed technician (manual specifies the gas control/thermostat should be replaced by a qualified tech)), but the repair is a licensed, TSBC-certified gas technician job. HeatLand diagnoses and fixes 4 flashes (standing-pilot) / Four Flash, three-second pause (power-vent) on John Wood water heaters throughout Greater Vancouver.

Is it safe to keep running a John Wood water heater with a fault code?

Most John Wood fault codes put the water heater into a safe lockout for a reason. You can safely check the basics — the gas supply on, the pilot light or igniter, the temperature dial setting, the breaker on (power-vent/electric/hybrid models), and no water leaking around the tank — and restart it once. If the code returns, stop and book a technician. If you 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. Never cap or block the temperature & pressure (T&P) relief valve, and don’t keep relighting a pilot that won’t stay lit.

John Wood water heater repair across Greater Vancouver

HeatLand has kept Metro Vancouver homes comfortable since 1999. Our licensed, insured technicians diagnose and repair John Wood water heaters — pilot and ignition faults, gas-control (status-light) codes, sensor and thermostat errors, vent and air-intake blockages, leak shut-offs, and (on hybrid/heat-pump and tankless models) control-board and component faults — 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 water heater 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 water heater repair. Explore Water Heater services, browse all water heater error codes by brand, or request a free estimate.

John Wood water heater service areas

We repair John Wood water heaters across Greater Vancouver and the Fraser Valley, including:

John Wood water heater error code FAQs

Can I reset my John Wood water heater myself?

Yes — power-cycling the reset button once is generally safe after you’ve checked the basics (the gas supply on, the pilot light or igniter, the temperature dial setting, the breaker on (power-vent/electric/hybrid models), and no water leaking around the tank). If the water heater faults again right away, stop and note the code — repeatedly resetting a water heater that keeps locking out can mask a real problem. Call a licensed, TSBC-certified gas technician to diagnose it.

What does the John Wood 4 flashes (standing-pilot) / Four Flash, three-second pause (power-vent) code mean?

On John Wood water heaters, 4 flashes (standing-pilot) / Four Flash, three-second pause (power-vent) commonly indicates over-temperature shutdown. eco / tco (energy cut off) limit lockout – the gas control's temperature sensor detected the water temperature exceeded the safe limit, and the main burner (and pilot, on standing-pilot) has been shut off. 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 John Wood water heaters you didn’t install?

Yes. HeatLand is brand-agnostic and services John Wood water heaters 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 John Wood water heater fault code an emergency?

No heat in cold weather is worth treating urgently. If you 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. Never cap or block the temperature & pressure (T&P) relief valve, and don’t keep relighting a pilot that won’t stay lit. For priority water heater repair across Greater Vancouver, call (604) 330-3812.

How much does John Wood water heater repair cost in Vancouver?

It depends on the fault. Many John Wood 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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