Heat Pump Not Turning On — Troubleshooting Guide for Vancouver Homeowners
Published: July 20, 2026 — BC Wide Home Services Ltd, doing business as BC Wide Heating & Air Conditioning — Greater Vancouver, BC
Quick Checks Before Calling for Service
If your heat pump is completely unresponsive, start with these simple checks: verify the thermostat has power — replace batteries if the display is blank; check that the thermostat is set to the correct mode (Heat or Cool) and the temperature setting is appropriate; inspect the circuit breaker for both the indoor air handler and outdoor unit — a tripped breaker is a common cause of a dead heat pump. Toggle the breaker fully OFF and back ON; check the outdoor disconnect switch — a pull-out type switch near the outdoor unit that should be firmly in place; look for a float switch that may have tripped — if the condensate drain is clogged, a safety switch shuts down the system. If the outdoor unit has a shutoff switch on the side (looks like a regular light switch), verify it is in the ON position.
No Power to the Outdoor Unit
If your indoor air handler runs but the outdoor unit is silent, there may be an issue specific to the outdoor unit. Check the outdoor disconnect switch first — it is typically a metal box mounted on the wall near the outdoor unit. Open the box and check if the fuses are intact or the breaker switch is in the ON position. The outdoor unit has its own breaker in the main electrical panel — verify it is on. If the unit has a service switch mounted on the exterior wall near the unit, ensure it is in the ON position. If all switches and breakers are on but the outdoor unit still has no power, there may be a wiring issue, a failed contactor, or a blown fuse inside the unit that requires professional diagnosis.
Thermostat Communication Issues
Modern heat pump thermostats are often communicating thermostats that require proper wiring and configuration. If the thermostat display is working but the system is not responding, check: the thermostat wiring — a loose wire at the thermostat or air handler can interrupt communication; the thermostat settings — ensure it is not in Emergency Heat mode (which bypasses the heat pump and runs only the backup heat); the schedule programming — a program may have overridden the current temperature setting; the Wi-Fi connection (for smart thermostats) — if the thermostat lost its network connection, some features may be unavailable; the thermostat itself — try a hard reset by removing the thermostat from its base plate for 30 seconds and re-attaching. If the thermostat is battery-powered, replace the batteries even if the display seems fine — low batteries can cause intermittent operation.
Safety Shutdowns and Lockouts
Heat pumps have multiple safety systems that can shut down the unit. A high-pressure switch lockout occurs if the refrigerant pressure exceeds safe limits — this indicates a dirty coil, blocked airflow, or overcharge. A low-pressure switch lockout indicates a refrigerant leak. A freeze protection lockout shuts down the system if the indoor coil temperature drops near freezing. A defrost failure lockout occurs if the control board detects the defrost cycle is not completing properly. Many lockouts require the system to be manually reset by cycling the power at the breaker for 30 minutes. However, if a lockout recurs after resetting, professional diagnosis is needed to identify the underlying cause and prevent repeated failures.