Tucson heating calls pile up on the first real cold night, usually sometime in October or November, after the equipment has sat in cooling mode since spring. Sabino Creek Heating & Cooling takes those calls for gas furnaces and for heat pumps. This page is the fork. The repair pages underneath it are furnace repair and heat pump repair. A system that still runs, and that you want checked before it is asked to work, is a fall heating tune-up. Narrower heating pages: furnace not turning on, heater smells burning, carbon monoxide safety, thermostat problems, ductwork, mini-split repair, maintenance visits, and the printable season checklist.
If you only have a minute: set the thermostat to Heat, not Emergency, and put the setpoint a few degrees above the room. Listen. An inducer motor and then silence is a furnace sequence. An outdoor unit that should start and does not is a heat-pump sequence. A rotten-egg smell is neither. Leave and call 911 or Southwest Gas.
More specific heating pages: no heat, what to check first, heat pump blowing cold air, emergency heat, igniter and flame sensor, short cycling, heater noises, and the first cold night. Cost and planning, with no invented prices: furnace replacement, heat pump cost, tune-up cost, dual fuel, and gas to heat pump.
Symptoms and how they’re checked
No price column here. We do not have a published part-price source we are willing to copy onto a furnace, and we do not invent one. The check is what a visit actually does.
| Symptom | Likely cause | How it’s checked |
|---|---|---|
| Nothing happens when the thermostat calls for heat | Thermostat mode, a tripped breaker, a door switch, or the control board | Heat mode and a setpoint above the room. One breaker reset. The blower door has to be on for the switch to close. |
| The inducer runs, then silence. No flame. | Hot-surface igniter, pressure switch, or the gas valve not opening | Watch the sequence: inducer, a proved draft, then glow. A cracked igniter often looks fine until it is tested. |
| Burners light for a few seconds and drop out | Dirty flame sensor | The flame is real. The sensor did not prove it, so the valve closes. Cleaning or replacing the sensor is the usual repair. |
| Heat starts, then the burners shut off | Limit switch from a packed filter or a blocked return | Filter, return grilles, and whether the blower is moving air before anyone condemns the heat exchanger. |
| A burning smell on the first fire of fall | Dust on a heat exchanger that sat all summer, or something that is not dust | A light smell that fades can be dust. A rotten-egg gas smell means leave the house. Do not use switches. Call 911 or Southwest Gas. |
| Burners stay lit and the blower never starts | Blower motor, the blower capacitor, or the board’s fan output | The blower is supposed to wait until the heat exchanger is warm. If it never starts, that delay is over and it is a fault. |
The furnace table is the gas-heat side. The heat-pump side is different enough to keep on its own page, and it is summarized here so you can pick the right form.
Symptoms and how they’re checked
No price column. These checks separate a heat pump that is doing its job from one that is not. A price comes after that, not from the symptom alone.
| Symptom | Likely cause | How it’s checked |
|---|---|---|
| Supply air feels cool, then warms, and the outdoor unit is running | Normal heat-pump delivery, or a defrost cycle | Give it several minutes. Defrost often stops the outdoor fan and can feel cool indoors, then the fan restarts and the air warms. |
| Air stays cold and the outdoor unit never starts | Thermostat left on Emergency Heat, a capacitor, a contactor, or the board | Mode should be Heat, not Emergency. Then the same electrical checks as a cooling failure. |
| Outdoor coil stays encased in ice | Defrost sensor, outdoor fan, or the charge | Do not chip the ice or pour water on the fins. The defrost cycle is watched, then the fan and the refrigerant. |
| Aux or Emergency heat on a mild evening | Strips running because the compressor is not | Outdoor unit should run in heat on a typical Tucson night. Strips are the backup, not the whole system. |
| Heat when the thermostat says Cool, or the reverse | Reversing valve | Whether cooling worked at the end of summer is the useful history. The valve is diagnosed, not guessed from one register. |
Replacement is a third path, not the opening assumption. An igniter or a flame sensor is a repair. A heat exchanger problem, or a compressor that has failed on an old heat pump, is a conversation. What changes the price of new cooling equipment, without a made-up Tucson price list, is on replacement factors. Published national ranges for a new air conditioner are on new AC cost. The choice between leaving the gas furnace and going to a heat pump is heat pump versus gas furnace.
Use the form on this page. Name, mobile phone, ZIP, and what’s going on are required. Say furnace, heat pump, or not sure. Street address can wait.