Coleman Furnace Blowing Cold Air in Greater Vancouver — Causes & Repair

If your Coleman furnace is blowing cold air through the registers, the most useful thing to understand is what’s usually happening inside: the blower motor is running normally, but the burners are either not lighting at all or are shutting down early, so the air moving through your Greater Vancouver home never gets warmed. It feels alarming on a damp February night, but in most cases it points to a small, fixable fault rather than a dead furnace.

Coleman is a Johnson Controls brand and shares its control platform and safety logic with sister brands like York and Luxaire, so the way it responds to a heating problem is predictable. When the control can’t confirm a safe, proven flame, it keeps the blower running to move air and cool the heat exchanger, and that is exactly why you feel cold air instead of no air. The fan working is actually a sign the electrical side is healthy; the problem is on the ignition or safety side.

ROMA Heating & Cooling has diagnosed cold-air complaints on Coleman furnaces across Vancouver, Burnaby, Surrey, Coquitlam and the North Shore since 1999. Below are the common causes, the checks you can safely make yourself, and the point where it becomes a licensed gas technician’s job.

What “blowing cold air” actually means on a Coleman furnace

There are two very different versions of this complaint, and telling them apart saves time:

• Cold air all the time, even when heat isn’t calling: the fan is simply running continuously, which usually points to a thermostat setting or a wiring issue rather than a furnace fault.
• Cold air only during a heat call: the furnace is trying to heat but can’t establish or hold a flame, so the blower delivers unheated air. This is the version that needs diagnosis.

The most likely causes on a Coleman furnace

📞 Talk to a licensed ROMA furnace technician — (604) 704-0300

Thermostat set to ON instead of AUTO

If the fan switch is set to ON, the blower runs constantly and pushes room-temperature air between heat cycles. Safe check: set the fan to AUTO and the system to HEAT, then confirm the air is warm during an actual call for heat.

Failed ignition

If the igniter, gas valve or flame never establishes a burner, the control still runs the blower and you get cold air. Safe check: confirm the gas is on and the filter is clean; the igniter and gas valve are technician items.

Dirty flame sensor dropping the flame

A flame sensor coated with residue tells the control it doesn’t “see” a flame, so the gas valve closes seconds after lighting and the blower purges cold air. Safe check: none internal — a technician cleans the sensor and measures flame current.

Overheat / high-limit trip

A clogged filter or blocked airflow makes the furnace overheat; the high-limit shuts the burners but keeps the blower running to cool the exchanger, so you feel cold air. Safe check: replace the 1-inch filter and open all supply registers.

Pressure-switch or venting fault

If the pressure switch doesn’t prove safe venting — often a blocked intake/exhaust or a backed-up condensate line in our wet climate — the burners won’t fire. Safe check: clear the outdoor vent terminals and the condensate drain.

Gas supply interrupted

A closed manual gas valve or an interrupted supply means ignition fails and only air moves. Safe check: confirm the gas shut-off at the furnace is open and other gas appliances work.

Cold-air quick-reference

Safe things to try once

Start simple. Set the thermostat to HEAT and the fan to AUTO, raise the setpoint a few degrees, and confirm batteries are good. Replace the 1-inch filter and open every supply register so airflow isn’t restricted. Make sure the blower door is fully closed — the door safety switch will prevent normal heating if it isn’t seated. Confirm the gas is on at the furnace and go outside to clear the intake and exhaust terminals and the condensate drain. Then cycle power at the furnace switch once and watch a full heat call. If warm air returns and stays, a restriction was the cause. If it goes cold again, stop and call a licensed gas technician. Never bypass a safety switch or jump the flame sensor to force it to run.

What a ROMA tech checks first

When we arrive for a cold-air complaint on a Coleman furnace, the first thing we do is watch a complete heat cycle so we can see exactly where it fails. If the igniter glows, gas is admitted and the burners light but then drop out, the flame sensor and its flame current are our prime suspects — a coated sensor is one of the most common cold-air causes we see across Metro Vancouver. If the burners never light, we test the igniter, verify the gas valve opens with correct supply pressure, and check the pressure switch and inducer for a venting fault. If the burners run but the high-limit keeps cutting them while the blower continues, we chase the airflow restriction: filter, blower wheel, coil and duct. We also read any stored blink code on the control board against the legend on the blower-door label, since that count narrows the search quickly. Everything is verified with instruments and a full observed cycle, so the repair fixes the real cause rather than the first guess.

Repair or replace?

Most cold-air faults are straightforward repairs — a flame sensor cleaning, an igniter, a pressure switch, a limit, or clearing a blocked vent — and are well worth doing on a sound Coleman furnace. Replacement only enters the conversation when a cracked heat exchanger is found, when the furnace is near the end of its service life and repairs are stacking up, or when an aging mid-efficiency unit in an older Vancouver home is a candidate for a high-efficiency upgrade with rebates. We’ll always quote the repair honestly first and only raise replacement when the numbers or a safety finding genuinely call for it.

Greater Vancouver context

Our mild, wet winters are hard on venting and condensate more than on the furnace itself. Sidewall intake and exhaust terminals on high-efficiency Coleman units get blocked by leaves, snow or nesting, and condensate traps in cool Burnaby and New Westminster mechanical rooms back up — both open the pressure switch and stop ignition, producing exactly this cold-air symptom. In older character homes and laneway suites, undersized or leaky return ducts cause the overheating that trips the limit. Keeping filters fresh, vents clear and drains open prevents most of it.

When to call — and when it’s an emergency

If you smell gas, leave the home and call FortisBC emergency and 911 from outside; do not troubleshoot. If a CO alarm sounds or anyone feels unwell, get everyone out and call 911. Short of that, if the safe checks don’t restore steady warm air, call a licensed gas technician rather than repeatedly resetting a furnace that keeps failing.

Why ROMA for Coleman furnaces in Vancouver

ROMA Heating & Cooling is a TSBC-licensed gas contractor (Gas licence LGA0202903), bonded, insured and Red Seal-trained, rated 4.8★ from 221 Google reviews. We diagnose why your Coleman furnace is blowing cold air, then repair the real cause with upfront flat-rate pricing and no hidden fees. Estimates on installs are free, 0% financing is available OAC, and we work seven days a week. See our furnace repair service or book a free estimate. We serve Vancouver, Burnaby, Richmond, Surrey, Coquitlam and the North Shore — call (604) 704-0300, reach our team, or ask about maintenance plans that keep cold-air faults from returning.

Frequently Asked Questions

Why is my Coleman furnace blowing cold air?

Usually the blower is running while the burners aren’t making heat. Common causes are the fan set to ON instead of AUTO, a failed ignition, a dirty flame sensor dropping the flame seconds after lighting, or a high-limit overheat trip from a clogged filter. Try the safe checks, and call ROMA at (604) 704-0300 if warm air doesn’t return.

My Coleman furnace lights then blows cold within seconds. What is that?

That pattern usually points to a flame-sensing problem. A flame sensor coated with residue tells the control it doesn’t see a flame, so the gas valve closes and the blower purges cold air. It isn’t a homeowner fix — a technician cleans the sensor and measures the flame current to confirm.

Is it safe to keep running my Coleman furnace while it blows cold air?

If it’s simply the fan set to ON, yes — switch it to AUTO. If the furnace is repeatedly trying and failing to heat, don’t keep resetting it. Repeated failed ignition or an overheating unit should be diagnosed. And never bypass a safety switch or jump the flame sensor to force heat.

Could a dirty filter make my Coleman furnace blow cold air?

Yes. A clogged filter restricts airflow and overheats the furnace, so the high-limit shuts the burners while the blower keeps running to cool the heat exchanger — and you feel cold air. Replace the 1-inch filter, open all registers, and if it keeps tripping, have the airflow checked.

Does ROMA repair Coleman furnaces in Greater Vancouver?

Yes. ROMA Heating & Cooling diagnoses and repairs Coleman furnaces across Vancouver, Burnaby, Surrey, Coquitlam and the North Shore. We are TSBC-licensed, bonded and insured, with upfront flat-rate pricing. Call (604) 704-0300 seven days a week.

Reviewed by the ROMA Heating & Cooling team — TSBC-licensed gas contractor (Gas LGA0202903), serving Greater Vancouver since 1999. Updated July 2026.

{“@context”: “https://schema.org”, “@graph”: [{“@type”: “Service”, “name”: “Coleman Furnace Blowing Cold Air in Greater Vancouver — Causes & Repair”, “serviceType”: “Furnace repair and fault diagnosis”, “description”: “Coleman furnace blowing cold air in Greater Vancouver? Learn the likely causes, safe homeowner checks, and when to call ROMA Heating’s licensed techs at.”, “provider”: {“@type”: “HVACBusiness”, “name”: “ROMA Heating & Cooling”, “telephone”: “+1-604-704-0300”, “address”: {“@type”: “PostalAddress”, “streetAddress”: “2800 Douglas Rd B”, “addressLocality”: “Burnaby”, “addressRegion”: “BC”, “postalCode”: “V5C 5B7”, “addressCountry”: “CA”}}, “areaServed”: [{“@type”: “City”, “name”: “Vancouver”}, {“@type”: “City”, “name”: “Burnaby”}, {“@type”: “City”, “name”: “Surrey”}, {“@type”: “City”, “name”: “Richmond”}, {“@type”: “City”, “name”: “Coquitlam”}, {“@type”: “City”, “name”: “North Vancouver”}, {“@type”: “City”, “name”: “West Vancouver”}, {“@type”: “City”, “name”: “New Westminster”}, {“@type”: “City”, “name”: “Delta”}, {“@type”: “City”, “name”: “Langley”}, {“@type”: “City”, “name”: “Maple Ridge”}, {“@type”: “City”, “name”: “Port Coquitlam”}, {“@type”: “City”, “name”: “Port Moody”}, {“@type”: “City”, “name”: “White Rock”}], “url”: “https://romaheating.ca/coleman-furnace-blowing-cold-air-greater-vancouver/”, “about”: {“@type”: “Product”, “name”: “Coleman furnace”, “brand”: {“@type”: “Brand”, “name”: “Coleman”}}}, {“@type”: “FAQPage”, “mainEntity”: [{“@type”: “Question”, “name”: “Why is my Coleman furnace blowing cold air?”, “acceptedAnswer”: {“@type”: “Answer”, “text”: “Usually the blower is running while the burners aren’t making heat. Common causes are the fan set to ON instead of AUTO, a failed ignition, a dirty flame sensor dropping the flame seconds after lighting, or a high-limit overheat trip from a clogged filter. Try the safe checks, and call ROMA at (604) 704-0300 if warm air doesn’t return.”}}, {“@type”: “Question”, “name”: “My Coleman furnace lights then blows cold within seconds. What is that?”, “acceptedAnswer”: {“@type”: “Answer”, “text”: “That pattern usually points to a flame-sensing problem. A flame sensor coated with residue tells the control it doesn’t see a flame, so the gas valve closes and the blower purges cold air. It isn’t a homeowner fix — a technician cleans the sensor and measures the flame current to confirm.”}}, {“@type”: “Question”, “name”: “Is it safe to keep running my Coleman furnace while it blows cold air?”, “acceptedAnswer”: {“@type”: “Answer”, “text”: “If it’s simply the fan set to ON, yes — switch it to AUTO. If the furnace is repeatedly trying and failing to heat, don’t keep resetting it. Repeated failed ignition or an overheating unit should be diagnosed. And never bypass a safety switch or jump the flame sensor to force heat.”}}, {“@type”: “Question”, “name”: “Could a dirty filter make my Coleman furnace blow cold air?”, “acceptedAnswer”: {“@type”: “Answer”, “text”: “Yes. A clogged filter restricts airflow and overheats the furnace, so the high-limit shuts the burners while the blower keeps running to cool the heat exchanger — and you feel cold air. Replace the 1-inch filter, open all registers, and if it keeps tripping, have the airflow checked.”}}, {“@type”: “Question”, “name”: “Does ROMA repair Coleman furnaces in Greater Vancouver?”, “acceptedAnswer”: {“@type”: “Answer”, “text”: “Yes. ROMA Heating & Cooling diagnoses and repairs Coleman furnaces across Vancouver, Burnaby, Surrey, Coquitlam and the North Shore. We are TSBC-licensed, bonded and insured, with upfront flat-rate pricing. Call (604) 704-0300 seven days a week.”}}]}]}