A heat pump that will not heat in January or will not cool in July is a system with a specific fault — and in Fort Collins, where the heating season runs 5,797 degree days and the design temperature is around 0°F (ASHRAE 99.6% value 0.1°F), the fault is usually one of a short list: the defrost cycle, the reversing valve, the refrigerant circuit, or the airflow. DNA Refrigeration repairs heat pumps across Fort Collins, and we are open 24 hours, every day. Call (970) 932-2324 any time, day or night.
Heat pump repair is diagnosis before parts: testing the thermostat and controls, the reversing valve and defrost system, the refrigerant circuit, and the airflow, to find the one component that has failed. A heat pump that blows cold air in winter, ices over, or runs constantly without reaching temperature is usually telling you exactly what is wrong — if the readings are taken.
Winter is when Fort Collins heat pumps are tested. A cold-climate system is rated to hold at least 70% of its capacity at 5°F, with a COP of 1.8–2.3, and on the Front Range most systems are dual-fuel, with a gas furnace behind them. When a heat pump will not heat, the fault is often in the handover: the defrost cycle not clearing the outdoor coil, the reversing valve not shifting, or the auxiliary heat staging stuck on or off. Each one has a different test, and each one has a different fix.
Altitude and sizing complicate the picture. Fort Collins sits at 5,003 feet, and air conditioning loses roughly 3% of capacity per 1,000 feet — roughly 10–20% here. A heat pump that was sized from a sea-level table will struggle on the hottest afternoons and the coldest nights alike, and no repair will fix a system that was never big enough. Part of a repair visit is telling the difference between a failed part and a system that was undersized from the start — and saying so plainly.
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, so heat pumps are sized from a Manual J load calculation at altitude, not from nameplate tonnage.
Every heat pump repair visit follows the same sequence: diagnose first, explain what failed, then repair and test. These are the six things that visit covers.
We test the thermostat and controls, read control-board fault codes, check the reversing valve and defrost system, measure refrigerant pressures, and verify airflow. Diagnosis comes before any part is replaced, so you are not paying for a component that was never the problem.
The defrost board, sensors and reversing valve are the heart of winter operation. A heat pump that ices over and stays iced is usually a defrost failure — and a system that cannot defrost loses capacity fast in a Fort Collins January.
Refrigerant pressures are measured against the manufacturer’s charging chart and the circuit is checked for leaks. A system that heats and cools a little worse every month usually has a slow leak. Refrigerant handling follows EPA Section 608 rules.
Capacitors, contactors, the compressor and the control board are tested with a meter. A capacitor drifting out of spec mimics a dead compressor; testing first is what keeps a repair from becoming a replacement.
Filters, coils and ductwork are checked. A heat pump cannot move heat without moving air, and a dirty coil or a clogged filter is the most common cause of a system that runs constantly without reaching temperature.
Sometimes a repair is the wrong spend — a failed compressor on an old system, or a refrigerant circuit that has leaked repeatedly. For context, ducted heat pump installs in Fort Collins were modelled at $6,750–$11,220 and cold-climate systems at $8,840–$15,340 (NumeralQ, October 2026), with actual installs running higher. When the numbers point toward replacement, we show you both sides.
Call (970) 932-2324 any time, day or night — we are open 24 hours. We ask what the heat pump is doing, whether it is heating or cooling season, and whether the outdoor unit is iced over. No-heat calls in freezing weather go to the top of the board.
The technician tests the controls, the defrost system, the refrigerant circuit and the airflow, and reads the control-board fault codes. 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 system 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 system is run through full heating and cooling cycles, refrigerant charge is verified, and the defrost cycle is tested. On dual-fuel systems the furnace handover is checked too.
Before leaving, we walk you through what failed and why, show you the filter the system should be running, and note anything worth watching. That is also the moment to book the next twice-yearly maintenance visit.
Call (970) 932-2324 any time, day or night — we are open 24 hours. We ask what the heat pump is doing, whether it is heating or cooling season, and whether the outdoor unit is iced over. No-heat calls in freezing weather go to the top of the board.
Reads refrigerant pressures and verifies charge against the manufacturer’s charging chart — the first reading on any not-heating or not-cooling call.
Finds refrigerant leaks in coils, flare connections and line sets. Refrigerant handling follows EPA Section 608 rules.
Tests capacitors, contactors, defrost sensors, reversing valve coils, and control board voltage.
Verifies a deep vacuum after any refrigerant-circuit repair — moisture or air left in the lines destroys compressors.
Measures compressor and fan motor current draw. A motor drawing high amps is a motor about to fail.
Supply and return air temperatures confirm the system is heating and cooling to specification after the repair.
A dual-fuel heat pump in Southridge that stops heating in January usually has a defrost problem: the outdoor coil ices over, the defrost cycle never clears it, and capacity falls away until the system locks out or the auxiliary heat runs constantly.
After: We test the defrost board and sensors, check the reversing valve, and verify the auxiliary heat staging and the furnace handover. Once the defrost cycle is working, the coil clears, capacity returns, and the system heats as designed.
Call (970) 932-2324 →A heat pump blowing warm air in July is usually a refrigerant or airflow problem: a slow leak that has finally dropped charge below the threshold, a reversing valve stuck in heat mode, or a coil so dirty it cannot move heat.
After: We measure refrigerant pressures, check the reversing valve, test for leaks, and inspect the coils and filter. The failed component is replaced and the charge is set by measurement — not topped up and hoped for.
Call (970) 932-2324 →A heat pump that starts and stops every few minutes is usually a control or airflow problem: a thermostat misreading temperature, a clogged filter, or a refrigerant charge issue tripping the safety controls. Why your heat pump keeps turning on and off wears out the compressor fast.
After: We check the thermostat, the filter and airflow, the refrigerant charge, and the control-board fault codes. Fixing the cause — rather than replacing a compressor that was never the problem — is what stops the cycling.
Call (970) 932-2324 →Most heat pump failures fall into a handful of patterns. Here are the ones we see most often, and how each one is diagnosed.
Ask a pro →We test the defrost system, the reversing valve, the auxiliary heat staging, and the refrigerant charge. A heat pump that will not heat in January is usually one of those four.
We measure refrigerant pressures, check the reversing valve, test for leaks, and inspect the coils and filter. A system that cools a little worse every month usually has a slow leak.
Some frost is normal; ice that builds and stays is a defrost failure, restricted airflow, or low charge. We test the defrost board and sensors before thawing anything.
Auxiliary heat that never stages off burns electricity all winter. We test the staging controls and the thermostat — and the electric bill is usually the giveaway.
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.
“Denis is very professional and good guy who understands the systems well and fixes them in minutes”
Eshwar IllaGoogle review · 3 months ago
✓ Verified“Great Company great service I use them for all my refrigeration and hvac needs”
David CheelyGoogle review · a year ago
✓ Verified| Problem | What we check or do |
|---|---|
| Heat pump not heating | We test the defrost system, the reversing valve, the auxiliary heat staging, and the refrigerant charge. |
| Heat pump not cooling | We measure refrigerant pressures, check the reversing valve, test for leaks, and inspect the coils and filter. |
| Outdoor unit icing over | Some frost is normal; ice that builds and stays is a defrost failure, restricted airflow, or low charge. |
| Auxiliary heat always on | Auxiliary heat that never stages off burns electricity all winter. |
The most common causes are a defrost cycle that is not clearing the outdoor coil, a reversing valve that is not shifting, auxiliary heat staging that is stuck, a thermostat problem, or low refrigerant charge. Check the filter and look at the outdoor unit: if it is iced over and staying iced, the defrost system needs diagnosis.
Briefly, that is normal — the defrost cycle reverses the system for a few minutes to clear frost from the outdoor coil, and the air feels cool during it. If the air stays cold, the problem is a defrost failure, a reversing valve fault, or low refrigerant charge, and the system needs diagnosis.
Weigh the age, the repair history, and the cost of the repair against replacement. A single part on a younger system is a repair. A failed compressor on an old system, or a refrigerant circuit that has leaked repeatedly, usually points toward replacement. For context, ducted heat pump installs in Fort Collins were modelled at $6,750–$11,220 and cold-climate systems at $8,840–$15,340 (NumeralQ, October 2026), checked November 2026.
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 heat pump that quits in January is an emergency — call (970) 932-2324 any time, day or night.
Tell us what the heat pump is doing — not heating, not cooling, icing over, running constantly. We are open 24 hours, every day, and we will diagnose the problem, show you what failed, and explain your options before any work starts. Call (970) 932-2324.
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. There is no email address for the business — the phone is the way to reach us.