A heat pump that does not start at all — no indoor fan, no outdoor unit, no response — has a power, control, or safety shutdown issue that can often be narrowed down with a few simple checks.
HeatLand Heating & Cooling installs and services heat pumps across Greater Vancouver.
Call (604) 330-3812 Get a Free QuoteWhat This Means
For a heat pump to start, it needs electrical power at both the indoor and outdoor units, a thermostat call for heating or cooling, and no active safety shutdown conditions. A problem at any of these three layers will prevent startup.
Common Causes
- Circuit breaker tripped for the indoor unit, outdoor unit, or both
- Disconnect switch at the outdoor unit open or failed
- Thermostat no signal or dead batteries
- Safety control lockout — high-pressure, low-pressure, or freeze protection trip requiring reset
- Control board failure
- Contactor in the outdoor unit failed open — no power reaching the compressor or fan motor
What Homeowners Can Check Safely
- Check the circuit breakers for the heat pump (typically two separate breakers — one for indoor air handler, one for outdoor unit)
- Replace thermostat batteries if battery-operated
- Check for a disconnect switch near the outdoor unit — it should be in the ON position
When to Call a Licensed Technician
Heat pumps contain refrigerant under pressure, electrical components at line voltage, and control systems that require specialized diagnostic tools. Do not open refrigerant circuits, bypass safety switches, or attempt to recharge refrigerant without proper certification.
- Contactor testing and replacement
- Control board power supply testing
- Safety control reset and root cause identification
- Capacitor testing — a failed start or run capacitor prevents the compressor or fan from starting
- Thermostat signal wire testing
Frequently Asked Questions
Why did my heat pump circuit breaker trip?
A tripped heat pump breaker usually indicates the unit drew more current than the breaker rating — from a compressor struggling to start (bad capacitor), a wiring fault, or a motor bearing failing. Resetting a tripped breaker once and observing whether it trips again is reasonable. If it trips again promptly, the underlying cause must be identified before further operation.
My heat pump was working yesterday but will not turn on today. What happened?
An abrupt shutdown often indicates a safety control tripped — high pressure, low pressure, or overtemperature protection. These require the underlying fault to be resolved and the lockout reset. On some heat pump models, turning the thermostat off for a few minutes then back on resets the lockout. If the unit starts but faults again quickly, the underlying problem (refrigerant, airflow, electrical) needs repair.
HeatLand services and installs heat pumps throughout Greater Vancouver. Call for expert diagnosis.
Call (604) 330-3812 Book a Heat Pump Check