What does auxiliary heat look like on the equipment?
Auxiliary heat is usually a set of electric heat strips inside the indoor air handler, behind a service panel, or a gas furnace paired with the heat pump. The nameplate on the air handler often lists the heater kit size, which confirms it.
Do not remove the service panel yourself to look. The panel covers live electrical parts, and the breakers feeding the heat strips carry a lot of current. The nameplate and the paperwork from the installation are safer places to look.
A technician can confirm the setup in a few minutes by checking the model numbers and the wiring, and can tell you whether the heat comes from strips or a furnace.
Older documents sometimes help as well. An installer's invoice or a permit record may list the heater kit, which saves guessing if the label is faded or hard to reach.
What is the difference between auxiliary heat and emergency heat?
Auxiliary heat turns on automatically when the heat pump needs help reaching the temperature, such as during a quick temperature jump. Emergency heat is a manual setting that turns off the heat pump and relies only on backup heat. Emergency should be used only when the heat pump has a problem.
Many people leave emergency heat on by mistake. It can quietly raise electric use because the backup strips do all the work. If your thermostat shows EM HEAT and nothing is wrong with the heat pump, switch back to normal heat.
A thermostat that shows AUX during a big setpoint change is normal. If it runs constantly on mild days, the heat pump itself may not be keeping up.
Why does my system use auxiliary heat so often?
A system uses auxiliary heat often when the heat pump cannot meet demand, due to big setpoint changes, dirty coils, low refrigerant, a stuck reversing valve or a failing compressor. Mild West Valley winters should rarely need much backup heat, so frequent use is worth investigating.
Start with simple steps. Replace the filter, keep the thermostat steady and avoid large overnight setbacks. These alone often reduce backup heat use.
If aux stays on and the house still feels cool, have the system checked. A technician can measure airflow, refrigerant levels and electrical function to find why the heat pump is falling behind.
Keep notes on when it happens. Whether aux runs only on cold mornings or all day tells a technician a lot about where to start looking.
What are the safety concerns with electric heat strips?
Electric heat strips draw a large amount of power and can overheat if airflow is blocked or components fail. Signs of trouble include a burning smell, a hot panel or breakers that trip repeatedly. Turn the system off and call a licensed electrician or AC technician.
A faint dusty smell the first time heat runs in the season can be normal, since dust burns off. A strong or lingering burning smell is not normal and means stop.
Vortech is licensed for both AC and electrical work, which suits heat pump backup heat since the problem might be mechanical or electrical. Use the call button on this page if something seems wrong.
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