Goodman AC won’t turn off — diagnosis guide
If your Goodman air conditioner has been running non-stop through a Metro Vancouver warm spell — or won’t shut off even after the house has clearly cooled down — it’s more than an annoyance. A unit that never cycles off wastes energy, accelerates wear on the compressor, and can eventually lead to a bigger repair bill.
The good news is that a continuously running AC is rarely a mystery once a technician has eyes on the equipment. It almost always traces back to one of a handful of general categories: a stuck electrical contact, a thermostat that isn’t reading the room correctly, or a wiring fault that’s fooling the control board into thinking the house is still warm.
Below we walk through what homeowners across the Fraser Valley and Metro Vancouver typically encounter, what a technician checks first, and when it’s time to shut the system down and call for service.
Why a Goodman AC Keeps Running
Central air conditioners cycle on and off based on a signal loop: the thermostat reads room temperature, sends a call for cooling to the control board, and the board energizes the outdoor unit’s contactor — an electromechanical relay that switches high-voltage power to the compressor and fan. When any part of that loop malfunctions, the system can get stuck in the ‘on’ position. Broadly, technicians group the cause into a few categories: a contactor whose contacts have physically welded together from repeated arcing, a thermostat that’s lost calibration or has a wiring fault making it believe the room is warmer than it is, a low-voltage short somewhere in the thermostat wire run between the air handler and the outdoor unit, or a control board relay that has failed in the closed position. Less often, a shorted run capacitor or a failed sensor feeding false data into the board can produce the same symptom. None of these are something a homeowner should diagnose by guesswork — the fix depends entirely on which component is actually at fault, and some involve line-voltage electrical components that require a licensed technician to test safely.
What a Technician Checks First
A HeatLand technician arriving at a Goodman AC that won’t shut off starts with the safest, most common culprit and works outward. First is a visual and continuity check on the outdoor contactor — pitting, arcing marks, or contacts that stay closed under a multimeter test point straight to a contactor swap. Next is the thermostat: verifying it reads accurately against a separate thermometer, checking the low-voltage terminals for correct wiring, and testing whether the ‘call for cooling’ signal drops when it should. If both check out, attention moves to the thermostat wire itself, since a nicked or pinched wire between the air handler and the condenser can create a short that keeps the R and Y terminals connected permanently. Finally, the control board is tested directly for a stuck relay. Because Goodman air handlers and condensers share components across many model years, verifying the exact part number and behaviour against the unit’s own service literature is standard practice — general symptom categories point the technician in the right direction, but confirmation always happens on-site against your specific equipment.
Risks of Letting It Run
A Goodman system that won’t cycle off isn’t just an energy drain, though a continuously running condenser will noticeably increase Metro Vancouver’s already-rising summer power costs. The bigger concern is mechanical: compressors and fan motors are designed for a duty cycle of on-and-off periods, and continuous run time shortens the life of both, especially if the underlying cause is electrical arcing at the contactor that’s also degrading nearby wiring insulation. If the unit is stuck on because of a low refrigerant condition being misread by a sensor, running continuously can also mean the compressor is working harder than intended for the actual cooling being delivered, straining components that are expensive to replace. The safest approach once you notice the pattern is to shut the system off at the thermostat or breaker and book a diagnostic visit rather than let it run for days waiting to see if it resolves itself.
Repair Factors That Affect Value
What a repair involves depends entirely on which component in the chain has failed. A contactor replacement is typically a straightforward, lower-complexity repair; a control board replacement is more involved because boards are model-specific and may need to be sourced for your exact Goodman air handler or condenser configuration; a thermostat wiring fault can range from a quick fix to a more time-consuming trace-and-repair job if the short is buried in a wall or attic run. Other factors that affect the scope of any repair include the age and accessibility of the outdoor unit, whether the system is still within a manufacturer parts warranty (worth checking your original paperwork or the unit’s data label), and whether any secondary damage occurred from extended run time. HeatLand provides a written, no-obligation estimate after an on-site or virtual assessment — there are no surprise charges added once your technician has actually looked at the equipment and confirmed the fault.
When to Call HeatLand
If your Goodman AC won’t shut off, the safest first step is to switch the thermostat to ‘off’ or flip the breaker feeding the outdoor unit, then call before flipping it back on. Continuing to run a unit stuck in a fault condition rarely fixes itself and can turn a simple contactor swap into a more involved repair if left unaddressed through a full cooling season. HeatLand has served Metro Vancouver and the Fraser Valley since 1999 as a licensed, insured, family-run company, and our technicians are familiar with Goodman systems across the range of ages installed in the region. Emergency service is available when a stuck-on system needs same-visit attention. Call (604) 330-3812 to book a diagnostic and get a written estimate before any repair work begins.
Quick Checklist
- Switch the thermostat to ‘off’ or shut the breaker to the outdoor unit if it won’t stop running
- Note whether the indoor fan, outdoor fan, or compressor (or all three) stay on continuously
- Check the thermostat display against a separate room thermometer for an obvious mismatch
- Avoid repeatedly resetting the breaker, which can mask a contactor arcing problem
- Have the model and serial number off the outdoor unit’s data label ready for your service call
- Book a diagnostic visit rather than letting the system run unattended for multiple days
| Possible Cause | General Symptom Pattern | Typical Fix Complexity |
|---|---|---|
| Stuck/welded contactor | Outdoor unit runs even with thermostat off | Lower — component swap |
| Thermostat calibration/wiring fault | Runs continuously despite room reading cool | Lower to moderate |
| Shorted low-voltage thermostat wire | Call for cooling never clears | Moderate — may require wire tracing |
| Control board relay stuck closed | System ignores thermostat signal entirely | Moderate to higher — board replacement |
| Sensor feeding false reading to board | Runs continuously alongside other symptoms (icing, poor cooling) | Varies — needs on-site diagnosis |
Frequently Asked Questions
Is it safe to keep running my Goodman AC if it won’t turn off?
It’s safer to shut it down at the thermostat or breaker and book a diagnostic. Continuous operation from a stuck contactor or board fault can accelerate wear on the compressor and fan motor, and in some cases increase the risk of further electrical damage. A short delay for a proper inspection is safer than ongoing unattended run time.
Could this be a simple thermostat battery issue?
It’s possible on battery-powered thermostats, but a stuck-on system is more commonly an outdoor contactor or wiring fault. Swapping batteries is a reasonable first check, but if the problem continues, the cause is likely elsewhere in the system and worth a professional look.
Will this repair be covered under my Goodman warranty?
That depends on your unit’s registration, age, and which component failed — parts and labour warranties differ and manufacturer terms should be confirmed against your original paperwork or Goodman’s own documentation. A HeatLand technician can help you determine coverage during the assessment.
How much will it cost to fix?
Cost depends on which component is at fault, parts availability for your specific model, and labour time. We don’t quote a number sight-unseen — HeatLand provides a written, no-obligation estimate after an on-site or virtual assessment so you know exactly what’s involved before any work begins.
Reviewed by the HeatLand Heating & Cooling team — licensed HVAC contractor serving Metro Vancouver & the Fraser Valley since 1999. Pricing, rebate programs, and product specs vary by home/building and change over time; confirm current details with a written quote and with CleanBC/FortisBC or your insurer/RTB as applicable. If you smell gas or your CO alarm sounds, stop, leave, and call a licensed technician or 911.