Furnace and heating repair in Phoenix, AZ

Phoenix winters are mild, with cool nights and short cold snaps. Heating runs for a small part of the year, and that changes what is installed. Many Phoenix homes have no furnace at all. They heat with a heat pump, which is the AC's outdoor unit running in reverse, often backed up by electric heat strips in the air handler. Homes with gas service usually have a gas furnace sharing ducts and a blower with the AC.

Which one you have decides what can go wrong. If the outdoor unit runs when the heat is on, you have a heat pump, and the heat pump not heating guide is the place to start. If you see a flue pipe and a gas line at the indoor unit, you have a furnace.

Because heating sits idle for most of the year, the first cold night is when problems show up. A dusty burning smell for the first few minutes is common as dust burns off the heat strips or heat exchanger. A smell that lingers, or any gas odor, is a different matter.

These checks cost nothing and solve a fair share of no-heat calls. They are the full list of what is safe to do yourself.

• Set the thermostat to Heat, raise the setpoint a few degrees above room temperature and replace the batteries if it has them.
• Check the breaker panel for a tripped breaker on the furnace, air handler or heat pump. Reset it once. If it trips again, stop and call.
• Find the power switch on or near the furnace or air handler, which looks like a light switch, and make sure it is on.
• Pull the filter. If it is gray and matted, replace it. A clogged filter can make the system overheat and shut itself off.
• Open the supply registers and clear furniture or rugs away from the return grille.
• Clear leaves and debris from around the outdoor unit if you heat with a heat pump.
• Write down any error code on the thermostat or the blinking light pattern visible through the furnace's sight window.

A technician starts by confirming the complaint, then reads fault codes and tests the parts most likely to have failed. On a gas furnace that is usually the igniter, flame sensor, pressure switch, inducer motor or a safety limit that tripped because of poor airflow. On a heat pump it is often a capacitor, contactor, reversing valve, defrost control or a refrigerant problem.

You should get the diagnosis and a price before any repair starts. Ask what failed, why it failed and whether anything else is close behind it. Ask to see the failed part.

Arizona licenses contractors through the Arizona Registrar of Contractors (ROC). Get the license number before the visit and check it using the Arizona license lookup guide. Confirm the business name, an active status and a classification that covers residential heating and cooling work.

A repair that swaps a part normally needs no permit. Replacing a furnace or heat pump commonly does, and the rule is set by the local building department. If the visit turns into a replacement quote, ask who pulls the permit and get it written into the price.

Heating equipment in the desert gets light use, so furnaces here often outlast the AC they are paired with. Repair is usually the right call for a single failed part. Replacement enters the picture when a furnace has a cracked heat exchanger, when a heat pump's compressor has failed, or when the indoor and outdoor equipment are both old and the AC side is failing too.

A cold house is rarely dangerous in a mild winter, but it can be for infants, older adults and anyone who is ill. If you cannot wait, the emergency furnace repair page explains what to do tonight.