Flame Sensor and Igniter
The flame sensor is cleaned and its microamp output tested; the igniter is checked for wear and continuity. These two parts cause most no-heat calls, and both are cheap to catch in September and expensive to find in January.
Fall furnace tune-ups before the heating season
Furnace Maintenance and Tune-Ups in Fort Collins
The best time to find a furnace problem in Fort Collins is September or October — not January, when the city is averaging 150 freezing nights a year and the heating season is already running. Furnace maintenance is the annual visit that cleans the flame sensor, checks the igniter, flushes the condensate drain, and verifies the furnace will hold temperature through 5,797 heating degree days. DNA Refrigeration does furnace maintenance across Fort Collins. Call (970) 932-2324.
Annual service before the heating season starts.
About this service
What Furnace Maintenance Covers — and When to Book It
Furnace maintenance is a once-a-year service visit, done in the fall before the heating season, that cleans, tests, and adjusts the parts that fail most often: the flame sensor, the igniter, the filter and blower, the condensate drain, and the safety controls. It is the difference between a furnace that starts the season clean and a furnace that limps through November and quits on the first real cold snap.
Timing is the whole point. Fort Collins’ heating season runs October/November through April, and the shoulder seasons — March–April and September–October — are the tune-up window. A September or October visit catches a weak igniter, a dirty flame sensor, or a condensate drain that will freeze, while there is still time to fix it. The national furnace-repair peak is January; a fall tune-up is how a home stays out of it.
The local failure list is short and specific. On older 80% furnaces — common in Old Town and Campus West — the igniter and flame sensor age out. On high-efficiency condensing furnaces — standard in Rigden Farm and newer Harmony Corridor builds — the condensate drain line is the weak point, freezing in an unheated space and shutting the furnace down on a pressure-switch fault. Maintenance checks both, plus the heat exchanger, the combustion readings, and the filter and airflow that protect the whole system.
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.
- ✓ Annual visit before the heating season
- ✓ Flame sensor cleaning and igniter check
- ✓ Condensate drain flush and freeze check
- ✓ Heat exchanger visual inspection
What's included
What a Furnace Maintenance Visit Includes
A maintenance visit is a checklist, not a guess. These are the six checks that make up a fall furnace tune-up in Fort Collins.
Filter and Airflow
The filter is checked for size and condition, the blower wheel is inspected, and temperature rise is measured against the data plate. A clogged pleated filter is the single most common cause of short cycling and high-limit trips.
Condensate Drain Service
On condensing furnaces the drain line is flushed, the trap is checked, and the pitch is verified. In Fort Collins, a drain that runs through an unheated space will freeze — maintenance is when that routing gets flagged, before the first hard freeze.
Combustion and Safety Check
Flue gas is read with a combustion analyzer and the heat exchanger is visually inspected. Carbon monoxide readings and exchanger condition are safety findings, not sales items: if either is off, you see the evidence.
Thermostat and Controls
The thermostat is tested for accurate temperature sensing and correct heat-call behaviour, and the control board is checked for fault codes. A thermostat that reads two degrees off is a comfort problem all winter furnace maintenance checklist.
Gas Pressure and Burners
Gas pressure is checked against the data plate and the burners are inspected for clean, even flame. At 5,003 feet, altitude changes the numbers — pressure is verified, not assumed from the sea-level setting.
How it works
What to Expect From Our Furnace Maintenance Visit
Call (970) 932-2324 in September or October, before the heating season. The shoulder season is the tune-up window — the furnace is accessible, parts are available, and there is time to fix anything found.
The technician works through the checklist: flame sensor, igniter, filter and blower, condensate drain, heat exchanger, thermostat, gas pressure, and control-board fault codes.
The flame sensor is cleaned, the drain is flushed, the filter is checked, and anything out of adjustment is corrected on the spot.
Combustion readings are taken on the flue gas and the heat exchanger is visually inspected. Safety findings are shown to you, not just noted.
You get a plain account of the furnace’s condition: what is fine, what is wearing, and what to watch. If a part is near the end of its life, you hear about it in October — not at 2 a.m. in January.
STEP 01Book in the Shoulder Season
Call (970) 932-2324 in September or October, before the heating season. The shoulder season is the tune-up window — the furnace is accessible, parts are available, and there is time to fix anything found.
Tools & methods
Tools and Methods We Use on Every Furnace Tune-Up
Multimeter
Tests igniter continuity, flame sensor microamp output, and control board voltage — the readings that decide whether a part is good or worn.
Combustion Analyzer
Reads oxygen, carbon monoxide and flue temperature, confirming the furnace burns clean and safe after service.
Brush and Vacuum Kit
Cleans the flame sensor, burner area and blower compartment without damaging the components.
Digital Manometer
Verifies gas pressure against the data plate at altitude.
Thermometer Set
Supply and return air temperatures, compared with the data plate, confirm the furnace is heating the air it moves.
Filter Gauge
Confirms the filter is the right size and type for the system — a filter that is too restrictive causes short cycling all winter.
Real results
Furnace Maintenance Across Fort Collins Neighbourhoods
Furnace Maintenance
Fall Tune-Up in Old Town
Old Town homes often run older 80% furnaces with original igniters and decades of heating history. The failure pattern is predictable: an igniter that has cycled thousands of times and a flame sensor coated in combustion residue.
After: A fall visit cleans the sensor, tests the igniter, and checks the heat exchanger and flue — the checks that keep an older furnace running safely through the season instead of quitting on the first cold snap.
Call (970) 932-2324 → Furnace Maintenance
Condensing Furnace Check in Rigden Farm
Rigden Farm’s newer homes run high-efficiency condensing furnaces, and their weak point is the condensate drain. A line through an unheated crawl space or along a cold wall freezes, and the furnace shuts down on a pressure-switch fault.
After: The maintenance visit flushes the drain, checks the trap and pitch, and flags routing that will freeze — so the fix happens in October, when it is a reroute, rather than in January, when it is an emergency.
Call (970) 932-2324 → Furnace Maintenance
Rental Turnover Check in Campus West
With only 51.6% of Fort Collins homes owner-occupied, landlords and property managers are a large part of the market — and Campus West rentals see the classic pattern: filters neglected between tenants and furnaces that have not been serviced in years.
After: A turnover maintenance visit resets the system: filter replaced, flame sensor cleaned, safety checks done, and the furnace documented as serviced before the next tenant moves in.
Call (970) 932-2324 → Problems we solve
Furnace Problems Maintenance Prevents
Most January furnace failures were visible in October. Here are the four that a fall tune-up catches first.
Ask a pro →Dirty flame sensor, short cycling
A flame sensor coated in residue shuts the burner down seconds after it lights. Cleaning it and testing its microamp output in the fall prevents the short cycling that strands homes in January.
Clogged filter, high-limit trips
A filter that has not been changed in months chokes airflow and trips the high-limit switch. Maintenance checks filter size and condition and measures temperature rise.
Frozen condensate drain
A condensate line through an unheated space freezes and shuts a condensing furnace down. The fall visit flushes the drain and flags routing that will not survive a hard freeze.
Worn igniter, no-heat failure
Igniters wear out with every cycle. Testing continuity in the fall finds the weak one before it fails on the coldest night of the year.
Proof you can check
How HVAC licensing works in Fort Collins
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.
- City of Fort Collins contractor licensing — HVAC is licensed locally, not by the State of Colorado
- Mechanical permits for furnace, AC and heat-pump replacements, applied for through the Accela Citizen Portal
- ACCA Manual J load calculations, sized for 5,003 feet of altitude
- Refrigerant handling follows EPA Section 608 rules
- 5.0 ★ (23 Google reviews) — every review on Google is five stars
Customer reviews
What Fort Collins Customers Say
★★★★★
“Denis always does a great job taking care of our 9 locations. Goes above & beyond to make sure our shops stay running smoothly. We have him do walk-in installations & maintenance, HVAC installation & maintenance, ice machine maintenance & installations, preventative maintenance & repairs on all of our sandwich tables and cabinets.”
TL
Tom LoftusGoogle review · a year ago
✓ Verified“
★★★★★
“Dennis is knowledgeable, honest, and reliable. Highly recommend!”
CM
Chad MolterGoogle review · a year ago
✓ VerifiedOnce a year, in the fall, before the heating season starts. That is the question Fort Collins homeowners ask most, and the answer is the same on every ranking local page: an annual fall visit, timed for the September–October shoulder season, when there is still time to fix anything the visit finds.
Flame sensor cleaning and testing, igniter check, filter and blower inspection, condensate drain flush and freeze check, heat exchanger visual inspection, combustion readings, thermostat testing, and gas pressure verification. You get a plain account of the furnace’s condition when the visit is done.
September and October. Fort Collins’ heating season runs October/November through April, and the shoulder season is the tune-up window. The national furnace-repair peak is January — a fall visit is how a home stays out of it.
It can catch the risk before it becomes a failure. The visit flushes the drain, checks the trap and pitch, and flags routing through unheated space that will freeze. Where the routing is the problem, rerouting the line inside conditioned space is the lasting fix — and October is the time to do it.
Ready when you are
Book the Fall Furnace Tune-Up: (970) 932-2324
September and October are the tune-up window in Fort Collins. Call (970) 932-2324 and book the fall furnace maintenance visit before the heating season starts — while a worn igniter or a drain that will freeze is still a small fix. We are open 24 hours, every day.
Call Now (970) 932-2324 →
Call to book
Get in Touch
Call us at (970) 932-2324 any time, day or night. We are open 24 hours, 7 days a week. There is no email address for the business — the phone is the way to reach us.
Call anytime(970) 932-2324
Office hoursOpen 24 hours · 7 days a week