Heat Pump Not Heating? New Jersey Troubleshooting Guide (2025)
A heat pump that runs but doesn’t heat is typically dealing with a thermostat issue, airflow restriction, refrigerant problem, outdoor unit malfunction, frozen coil, or a reversing valve failure. In New Jersey’s cold winters, heat pumps can struggle if there is a mechanical issue or if the system goes into defrost mode too often.
Quick Heat Pump Checklist Before You Call for Service
- Is the thermostat set to “Heat” or “Emergency Heat”?
- Is the outdoor unit frozen over with ice?
- Is the air filter clogged?
- Is warm air blowing inconsistently or not at all?
- Is the outdoor fan running?
- Did the system recently switch into defrost mode?
- Is the breaker tripped for the indoor or outdoor unit?
Common Reasons a Heat Pump Stops Heating in New Jersey
Outdoor Unit Frozen
New Jersey humidity and freezing temperatures can cause the outdoor unit to ice over. A light frost is normal during cold weather, but heavy, solid ice indicates a problem with the defrost cycle.
Dirty or Clogged Filter
Restricted airflow prevents heat transfer and forces the system to shut down or blow cold air. Replace the filter and allow the system to run for 30–60 minutes.
Low Refrigerant
Heat pumps require proper refrigerant levels to move heat. A low charge usually indicates a leak. Symptoms include weak heating, ice buildup, and longer run times.
Reversing Valve Failure
The reversing valve is responsible for switching between heating and cooling. If it fails, the system may get stuck in cooling mode and blow cold air even in winter.
Thermostat Problems
Old thermostats or incorrect settings can cause erratic heating. Make sure the thermostat is set to Heat, not Cool, and increase the temperature several degrees above room temperature to test.
Defrost Cycle Issues
Heat pumps naturally go through defrost mode in winter. If defrost cycles run too frequently or don’t start at all, the outdoor unit may freeze and stop heating.
Outdoor Fan Motor Problems
If the outdoor fan isn’t spinning, heat cannot be absorbed from the outside air. This leads to cold air blowing inside. Electrical issues, a failing capacitor, or a bad fan motor can cause this.
Dirty Outdoor Coil
Debris, leaves, and dirt on the outdoor coil reduce heating efficiency. In Woodbridge and surrounding New Jersey towns, fall debris and winter conditions often cause coil obstruction.
What Temp Control Technicians Check
- Airflow and filter condition
- Refrigerant levels and leak detection
- Reversing valve operation
- Thermostat accuracy and wiring
- Outdoor coil condition
- Defrost cycle and sensors
- Compressor performance
- Electrical components and safety controls
When to Call for Heat Pump Repair
Call for service if:
- The outdoor unit is completely frozen solid
- The system blows cold air for more than 20 minutes
- Only emergency heat works
- The heat pump runs constantly without warming the home
- The thermostat won’t trigger heat
- You hear loud grinding, hissing, or buzzing noises
How to Prevent Heat Pump Problems
- Change filters every 60–90 days
- Keep the outdoor unit clear of snow, leaves, and debris
- Schedule annual heating tune-ups
- Inspect outdoor coils during winter for frost buildup
- Trim vegetation around the outdoor unit
Service Area
Temp Control provides heat pump repair and heating services in Woodbridge, Edison, Iselin, Colonia, Fords, Perth Amboy, Avenel, Carteret, Clark, Rahway, Linden, and surrounding New Jersey communities.
Get Fast Heat Pump Repair in New Jersey
Temp Control offers same-day heat pump repair in Woodbridge and throughout Middlesex and Union County. Our trained technicians diagnose heating problems quickly and restore comfort to your home.
Call Temp Control at (732) 218-8400 for reliable heat pump service in New Jersey.