Signs of a boiler ignition problem

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What an Ignition Problem Actually Is

Modern gas boilers use an electronic ignition system instead of a standing pilot light. When you call for heat, the control board opens the gas valve and fires an ignitor (either a hot-surface ignitor or a spark/electrode igniter) to light the burner. A flame sensor (also called a flame rod) then confirms a stable flame is present within a couple of seconds. If ignition fails, or if the flame sensor doesn't detect a flame quickly enough, the control board cuts gas flow and locks out the burner as a safety measure. Older atmospheric boilers with a standing pilot can have a related but separate issue: the pilot light itself going out, usually tied to a worn thermocouple or thermopile rather than the ignition module.

Common Signs of a Boiler Ignition Problem

• The boiler runs (pump, fan, or inducer motor is audible) but no heat is produced — the burner never actually lights
• A fault, lockout, or ignition-error light is blinking on the control panel or display
• You hear repeated clicking or sparking sounds with no flame catching
• The burner lights briefly, then the boiler shuts down again seconds later (short-cycling on ignition failure)
• A standing pilot light won't stay lit, or keeps blowing out
• The boiler needs to be manually reset (reset button pressed) every time it's called on for heat
• A burning or gas-like smell for a moment at startup, then nothing
• Inconsistent hot water or heating performance that traces back to the burner failing to fire reliably

What Usually Causes Ignition Failure

Ignition problems have a handful of recurring causes in Metro Vancouver homes. A cracked, worn, or dirty hot-surface ignitor is one of the most common — these are ceramic components that degrade with age and heat cycling. A dirty or corroded flame sensor can also be the culprit: it senses a flame is present through a tiny electrical signal (microamp current), and even a thin layer of soot or oxidation on the rod can make the control board think there's no flame, so it shuts the gas off even though the burner did light. A failing gas valve, low or inconsistent gas supply pressure, a blocked or misaligned burner, a faulty control board, or airflow/venting restrictions (a blocked intake or exhaust terminal, common after storms or with vegetation growth) can all trigger ignition lockouts as well. On older units, a worn thermocouple or thermopile is the typical reason a standing pilot won't stay lit.

What Homeowners Can Safely Check

There are a few things you can safely look at before calling for service, without touching the gas train or electrical components:

• Check that the boiler's power switch is on and any breaker hasn't tripped
• Confirm the thermostat is calling for heat and has working batteries if applicable
• Look at the control panel for an error code and, if the manufacturer's manual shows a simple reset procedure, try it once
• Visually check outdoor intake/exhaust vent terminals (on sealed-combustion units) for obstructions like snow, leaves, or a bird's nest, and clear debris away from the outside only
• Check that any manual gas shutoff valve to the boiler hasn't been accidentally closed
• Note whether the issue is constant or intermittent, and whether it happens right at startup — this detail helps a technician diagnose faster

If a reset doesn't hold, or the lockout repeats, stop trying to force it. Repeated forced resets on a genuine ignition fault can push unburned gas into the heat exchanger or flue, which is a safety risk, not just an inconvenience.

What Requires a Licensed Gas Technician

Everything beyond the checks above is licensed work in BC. Technical Safety BC requires anyone servicing, adjusting, or repairing gas appliances and gas piping to hold a valid gas licence — this covers the ignitor, flame sensor, gas valve, control board, burner assembly, and venting system. It's not just a legal requirement; these components involve combustion, gas pressure, and exhaust safety where a small mistake has real consequences. CANRO's technicians hold Technical Safety BC gas licence LGA0043870 and boiler licence LBP0046450, and are Red Seal certified, so this work is done to code with proper permits pulled where required.

What to Expect From a Service Visit

Many ignition faults are relatively inexpensive fixes — a flame sensor cleaning or ignitor replacement — while others, especially on an older boiler nearing the end of its service life, may point toward a bigger decision. If a technician tells you a boiler is failing repeatedly and repair costs are stacking up, ask for a written comparison between repair and replacement so you can decide with real numbers in front of you rather than guessing.

Repair vs. Replace: When Ignition Trouble Signals It's Time for a New Boiler

A single ignition fault on a boiler that's otherwise in good shape is usually just a repair. But if your boiler is older, has had multiple lockouts or ignition-related service calls, or the control board itself is failing, replacement is worth discussing. In Metro Vancouver, boiler replacement with a high-efficiency unit typically runs $7,500-$15,000+ installed, while a full new boiler installation (including cases where venting or gas line work is needed) runs $6,500-$14,000+, before any rebates. Current programs that can offset the cost include the interest-free Canada Greener Homes Loan (up to $40,000), the Oil to Heat Pump Affordability program where applicable, and CleanBC, BC Hydro, and FortisBC rebates depending on the equipment chosen — program details and amounts change, so confirm exact figures at quote time. A free written quote is the most reliable way to compare repairing your existing boiler against replacing it.

Frequently asked questions

Reviewed by the CANRO Heating & Cooling service team — June 30, 2026. CANRO holds Technical Safety BC gas licence LGA0043870 and boiler licence LBP0046450, employs Red Seal certified technicians, and carries WorkSafeBC and liability insurance. 4.9★ from 85+ Google reviews · serving Metro Vancouver since 1999 · (604) 359-1081 · info@canroheat.ca.