Why Is Your Summer Electric Bill So High? Start With the AC.

Phoenix dust blankets filters, evaporator coils, and condenser fins. Every layer insulates the surfaces that move heat, so the system runs longer to deliver the same cooling — same thermostat setting, bigger bill. The most common cause and the cheapest fix: a filter you can check right now, and coil cleaning as part of a maintenance visit.

Valley attics run 130°+ all summer, and decades of that heat crack duct mastic and flex-duct jackets. Supply leaks pour your cooled air into the attic; return leaks pull hot, dusty attic air back in. You pay to cool air that never reaches a room. If your bill outruns similar homes and rooms never balance, ducts are the suspect before the equipment is.

Most APS and SRP residential plans now price electricity by time of day — afternoon on-peak hours cost several times the off-peak rate, exactly when your AC works hardest. If your household can't shift usage (or pre-cool before the peak window), the same kilowatt-hours cost meaningfully more. Check which plan you're on in your utility account; it's a free phone call to change.

Compressors lose efficiency before they fail — an aging system draws more amps for less cooling every summer, and the bill creeps up years before the breakdown. If your system is past its 10th Valley summer and bills climb every year without a rate change, have the amp draw measured during a maintenance visit.

A system that never reaches setpoint on 110° afternoons is either losing capacity (dust, refrigerant, ducts) or was undersized from day one. Nonstop running is the most expensive way to be uncomfortable. The honest diagnosis is a measurement — airflow, charge, and a Manual J load calculation — not a bigger unit by default.