What should I do if my heat pump will not turn on?

What this symptom usually means

A heat pump that will not turn on is different from one that runs poorly, blows the wrong temperature, or makes noise. This symptom means the startup sequence is failing at the beginning: either the equipment has no power, the controls are not sending a valid start signal, or a component is preventing the indoor or outdoor section from energizing. Whether the system is completely silent, gives one click, hums briefly, or shows a fault code helps narrow the fault much faster than room temperature alone.

What you can tell from what you see and hear

If both the thermostat and the equipment seem dead, a power supply problem is more likely, especially after a storm, electrical work, or a recent breaker trip. If the thermostat lights up normally but neither the indoor blower nor outdoor unit starts, the problem often shifts toward a low-voltage fuse, thermostat wiring, or a control board issue. If the indoor unit runs but the outdoor unit is silent, or you hear a click followed by nothing, the outdoor disconnect, contactor, or capacitor becomes more likely. If the display shows a code or alert, that usually means the system tried to protect itself and locked out rather than simply losing power.

How a technician separates the common causes

On a no-start call, the visit usually begins with confirming power at the breaker panel, the service disconnect, and the air handler or furnace control compartment. The technician then checks whether the thermostat is actually sending a 24-volt call and whether any control fuse is open. If the unit clicks or hums, electrical testing often moves to the contactor, capacitor, blower motor, outdoor fan motor, and compressor circuit. When a fault code is present, the code is only the starting point; the real job is finding what triggered the lockout and whether it was a one-time event or an active failure.

What usually gets repaired on this kind of call

Repairs for a heat pump that will not start are often electrical or control related rather than airflow related. Common fixes include replacing a failed dual-run capacitor, contactor, low-voltage fuse, thermostat, transformer, or a damaged control wire, as well as correcting a loose connection at the disconnect or breaker. More involved repairs include blower motor replacement, control board replacement, or diagnosing a compressor that is locked, grounded, or drawing excessive amperage. If a safety switch or fault code is involved, the underlying cause still has to be corrected or the shutdown will return.

What affects repair cost

Cost depends mainly on which section failed and whether the fault is a simple power/control issue or a major motor/compressor problem. Typical 2025-2026 U.S. repair estimates are roughly $150-$400 for a capacitor, contactor, fuse, or minor electrical repair, about $200-$650 for thermostat, transformer, or basic control repairs, around $600-$1,500+ for blower motor or control board work, and often $1,500-$3,500+ if the compressor or major outdoor components are involved. Final price also changes with system age, brand-specific parts, after-hours timing, and whether repeated breaker trips caused additional damage.

If you noticed a breaker trip, code, click, or short hum before shutdown, mention that when arranging service because it helps the contractor bring the right test equipment and likely replacement parts. HVAC Rescue is a referral service, not the company performing the repair, so pricing, arrival times, and parts availability depend on the independent contractor you choose.