Furnace and heating repair in Mesa, AZ

Mesa sits in the low desert of the East Valley, where the heating season is short and the AC does most of the work. Home heating here comes in three common forms: a heat pump, a gas furnace paired with the AC, or a rooftop package unit that holds heating and cooling in one cabinet. Electric heat strips often serve as backup.

Start by working out which you have. A heat pump's outdoor unit runs in heating mode, so if it is silent while the thermostat calls for heat, see the heat pump not heating guide. A gas furnace has a gas line and a flue. A package unit on the roof is not something to inspect yourself, so stay off the roof and leave it to the technician.

Heating equipment that rests for most of the year tends to fail on the first cold morning. Expect a brief dusty smell at first start. If the smell continues, the blower runs with no warm air, or the system starts and stops every few minutes, shut it off at the thermostat and book a visit.

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.