Fort Collins runs on its furnaces. NOAA 1991–2020 data puts the city at 5,797 heating degree days against just 624 cooling degree days — roughly nine times as many heating degree days as cooling degree days — with about 150 nights a year at or below freezing and January lows averaging 18.3°F. When a furnace quits on a night like that, it is not an inconvenience, it is a cold house and a pipe-freeze risk. DNA Refrigeration repairs gas furnaces across Fort Collins, and we are open 24 hours, every day. Call (970) 932-2324 any time, day or night.
Furnace repair is the work of finding out why a gas furnace stopped heating, then fixing the failed component so the system runs safely and holds temperature again. That means testing the igniter and flame sensor, checking the inducer motor and pressure switch, reading the control board for fault codes, and confirming the blower moves air through the ductwork. A furnace that lights and quits, blows cold air, or short cycles usually has one failed part, not five.
Fort Collins housing makes the failure patterns predictable. Nearly half the city’s homes were built before 1990 — 46.5% of the stock — so a large share of furnaces are on their second or third cycle, with original igniters and blower motors reaching the end of their service life. Older homes in Old Town and Campus West often still run 80% furnaces, while newer builds off Harmony Corridor and in Rigden Farm use high-efficiency condensing units, which bring a different failure: the condensate drain line freezing in an unheated space and shutting the furnace down on a pressure-switch fault.
Altitude shapes the diagnosis too. Fort Collins sits at 5,003 feet, and the City’s mechanical guide puts furnace derating at 10–20% at this elevation — sea-level ratings do not apply here. A furnace that was sized from a sea-level table runs long cycles and still leaves rooms cold, which looks like a repair problem but is really a sizing problem. Good repair work in this city starts with the temperature rise across the heat exchanger and the data plate, not with a guess.
Every furnace repair visit follows the same sequence: diagnose first, explain what failed, then repair and test. These are the six things that visit covers.
We pull fault codes from the control board, test the igniter and flame sensor with a multimeter, check the inducer motor and pressure switch, and read static pressure across the blower. Diagnosis comes before any part is replaced, so you are not paying for a component that was never the problem.
The two most common no-heat failures in Fort Collins are a failed igniter and a dirty flame sensor. A furnace that clicks but never lights, or lights and quits after a few seconds, usually points at one of these two parts. Both are tested with a meter, not swapped on a hunch.
A furnace that fires but never warms the house usually has an airflow problem: a clogged filter, a failed blower capacitor, or a blower motor that has given up. We test the capacitor first, since a capacitor failure mimics a dead motor, and verify the temperature rise matches the data plate before calling the job done.
Every gas furnace repair ends with a combustion reading on the flue gas and a visual heat exchanger inspection. If carbon monoxide levels are off or the exchanger shows cracking, we show you the evidence and explain the options. A cracked heat exchanger is a safety issue, not a sales conversation.
High-efficiency furnaces produce water, and that water has to drain somewhere. We flush the condensate drain line, check the trap, and verify the line is pitched so it does not freeze and shut the furnace down again. On problem installs, rerouting the line inside conditioned space is the lasting fix.
Sometimes a repair is the wrong spend. Nationally, furnace repairs published by Angi in October 2026 ran $130–$1,200, while Fort Collins contractor-quoted furnace installs ran $7,000–$10,000 in 2026 (Lion, Fort Collins, for ultra-low-NOx models, including permit, venting and commissioning). When the numbers point toward replacement, we show you both sides and let you decide.
Call (970) 932-2324 any time, day or night — we are open 24 hours. We ask what the furnace is doing, how old it is, whether you smell gas, and whether the house is losing heat fast. If it is a no-heat call in freezing weather, it goes to the top of the board.
The technician pulls fault codes, tests the igniter and flame sensor, checks the inducer motor and pressure switch, and reads static pressure across the blower. This is the step that separates a repair from a guess: the failed component is identified with a meter before anything is replaced.
We show you the failed part, explain what it does, and lay out the options — repair now, or, where the furnace is old and the repair is a large share of replacement cost, the replacement picture too. Nothing is installed until you approve the work.
The part is replaced, the furnace is fired, and it is watched through a full heat cycle. Temperature rise is checked against the data plate, the flue is read with a combustion analyzer, and on high-efficiency units the condensate drain is verified flowing clear.
Before leaving, we walk you through what failed and why, show you the filter the system should be running, and note anything worth watching — a blower that is getting loud, a drain line that will freeze again. That is also the moment to book the fall furnace maintenance visit.
Call (970) 932-2324 any time, day or night — we are open 24 hours. We ask what the furnace is doing, how old it is, whether you smell gas, and whether the house is losing heat fast. If it is a no-heat call in freezing weather, it goes to the top of the board.
Tests igniter continuity, flame sensor microamp output, capacitor ratings, and control board voltage. This is the first tool out of the bag on almost every furnace call.
Reads oxygen, carbon monoxide, and flue temperature on every gas furnace repair. It confirms the furnace is burning clean and safe before the job is finished.
Checks gas pressure at the valve and verifies manifold pressure matches the data plate for your furnace model — essential at 5,003 feet, where altitude changes the numbers.
Finds hot spots on the control board, blocked duct runs, and heat exchanger problems that a visual inspection alone can miss.
Supply and return air temperatures across the heat exchanger, compared with the data plate. It is the simplest honest check that a furnace is actually heating the air it moves.
Measures how much conditioned air escapes through duct leaks. It tells us whether a furnace problem is really an airflow problem hiding in the ductwork.
A furnace that clicks through its ignition sequence and never lights, then locks out, is one of the most common winter furnace maintenance checklist calls in Fort Collins. The house cools steadily while the thermostat keeps calling for heat, and the fault code on the control board points at ignition failure.
After: We test the igniter for continuity and the flame sensor for microamp output, replace whichever component has actually failed, and watch the furnace fire and run a full heat cycle before leaving. The temperature rise is checked against the data plate so the repair is verified, not assumed.
Call (970) 932-2324 →High-efficiency condensing furnaces in newer Rigden Farm homes produce acidic condensate that must drain away. When the drain line runs through an unheated crawl space or along a cold exterior wall, a hard freeze turns it into a plug, and the furnace shuts down on a pressure-switch fault.
After: We thaw the line, flush the trap, and check the pitch. Where the routing is the problem, the lasting fix is rerouting the drain inside conditioned space or insulating and protecting the exposed run, so the same freeze does not shut the furnace down again next January.
Call (970) 932-2324 →A furnace that fires and runs yet never brings the house up to temperature is usually an airflow failure, not a burner failure. The usual suspects are a filter that has not been changed in months, a blower capacitor that has failed, or duct leakage dumping heated air where nobody lives.
After: We check the filter, test the capacitor and blower motor, and measure temperature rise and static pressure.
Call (970) 932-2324 →Most furnace failures fall into a handful of patterns. Here are the ones we see most often in Fort Collins homes, and how each one is diagnosed.
Ask a pro →We test the igniter for continuity and the flame sensor for microamp output. Most of these repairs are a failed igniter or a flame sensor that needs cleaning, and the diagnosis is confirmed with a meter before any part is changed. If the furnace stopped after a power outage, see how to reset your furnace after a power outage safely first — a reset is different from a failed part.
We check the flame sensor, the high-limit switch, the thermostat, and the airflow. A clogged pleated filter or a failing high-limit is usually the cause. We fix the restriction and verify the furnace runs a full cycle.
We test the blower motor capacitor first, since a capacitor failure mimics a dead motor. If the motor is truly gone, we replace it and verify the correct speed tap for your ductwork.
We thaw the line, flush the trap, and reroute or insulate the drain so it does not freeze again. On problem installs, we reposition the line to drain inside the conditioned space.
Colorado has no state HVAC licence — HVAC work in Fort Collins is licensed by the City of Fort Collins, not the state. Colorado licenses only electricians and plumbers at the state level. Fort Collins licenses HVAC contractors through the City — ask us for our licence details when you call. We pull a mechanical permit for replacements through the City’s Accela portal, and size equipment to ACCA Manual J. Refrigerant handling follows EPA Section 608 rules.
“Dennis is great. Doesn't give up till the job is done right. He really takes pride in his work. I highly recommend him.give him a call.you won't be sorry. He's like family from the minute you meet him.”
SueGoogle review · 3 months ago
✓ Verified“Denis is very professional and good guy who understands the systems well and fixes them in minutes”
Eshwar IllaGoogle review · 3 months ago
✓ VerifiedFigures already published on this page: Angi, October 2026; Lion, Fort Collins, 2026.
| Failed part | Published repair range | What we recommend |
|---|---|---|
| Flame sensor or igniter | $130–$1,200 (Angi, October 2026) | Repair — the low end of the range |
| Blower motor or control board | $130–$1,200 (Angi, October 2026) | Repair, or compare against replacement |
| New ultra-low-NOx furnace, including permit, venting and commissioning | $7,000–$10,000 (Lion, Fort Collins, 2026) | Replace — when the numbers point that way, we show you both sides and let you decide |
Short cycling, blowing cold air, clicking without lighting, a furnace that runs constantly without reaching the set temperature, new noises, or a sudden jump in gas use. A burning smell on the first cold-weather start-up usually clears in an hour; a gas smell never does — leave the house and call your gas utility from outside.
Yes. DNA Refrigeration is open 24 hours, every day, and no-heat calls in freezing weather are the priority. Fort Collins sees about 150 nights a year at or below freezing, so a dead furnace in January is an emergency — call (970) 932-2324 any time, day or night.
Nationally, Angi published furnace repair at $130–$1,200 in October 2026, with the part driving the price — a flame sensor or igniter at the low end, a blower motor or control board at the high end. For context on the replacement side, Fort Collins contractor-quoted furnace installs ran $7,000–$10,000 in 2026 (Lion, Fort Collins, ultra-low-NOx models, including permit, venting and commissioning), checked November 2026. A repair is quoted once the failed part is identified.
The most common causes are a thermostat set to fan-only instead of heat, a dirty flame sensor shutting the burner down, a failed igniter, a tripped high-limit switch from restricted airflow, or — on high-efficiency furnaces — a frozen condensate drain. Check the thermostat setting and the filter first; if the burner still will not stay lit, the furnace needs diagnosis.
A dead furnace on a freezing Fort Collins night is not something to sleep on. We are open 24 hours, every day — call (970) 932-2324 and tell us what the furnace is doing. We will diagnose the problem, show you what failed, and explain your options before any work starts.
Call Now (970) 932-2324 →Call us at (970) 932-2324 any time, day or night. We are open 24 hours, 7 days a week, for emergency furnace repair and routine service alike. There is no email address for the business — the phone is the way to reach us.