A York air conditioner that will not start, will not cool, or trips the breaker is almost always one of five parts: the dual-run capacitor, the contactor, the condenser fan motor, the compressor, or the control board. Which one depends on the symptom — and which exact OEM replacement fits depends on the model number stamped on the data plate. This guide maps every common symptom to the failed component, then maps the component to the correct York OEM Source 1 part number for your unit.
The quick answer: humming with no fan is the capacitor. Clicking contactor with no compressor start is the contactor. Compressor running with a silent fan is the fan motor or fan side of the capacitor. Nothing at all with power confirmed at the disconnect is the control board or a tripped safety. Pull the York model and serial off the data plate, match the component against the Source 1 catalog, and either verify fitment yourself or call HVACMORE at 855-575-4822 with those two strings in hand.
Why the York model number matters for AC troubleshooting
HVAC parts fit by model number, not by brand. A York YXV Affinity variable-capacity condenser and a York YCG LX single-stage condenser both say “York” on the lid and share almost no internal components. Order a “York condenser fan motor” without the model number and the odds of getting the right one are around 40 percent. Order it with the model in hand — and the Source 1 part number from the failed motor itself — and the match is deterministic.
The second reason the model matters: York residential ACs use five different control-board families, three different compressor technologies (single-stage, two-stage, inverter), and two refrigerants in current production (R-410A legacy, R-454B as of 2025 under the EPA SNAP transition). A board that fits a YXV6024B21 will brick a YCG4830A1. Both are York. Both carry the Johnson Controls label.
If you already know how to find and decode a York model number, skip to the symptom chart below. If not, start with the York Model Number Lookup guide to pull the string before you call parts.
Where to find the model number on a York air conditioner
The data plate is a silver or white adhesive sticker riveted to the side of the condenser cabinet, almost always on the side facing the house. It is roughly the size of a smartphone and stamped with text in black ink. Marked at minimum:
- M/N — model number, a 10 to 16 character string starting with letters that identify the product family (YXV, YCG, YHE, YZH, etc.)
- S/N — serial number, shorter, encoding the manufacturing plant and the week-year of production
- Electrical specs: voltage, phase, minimum circuit ampacity (MCA), maximum overcurrent protection (MOP)
- Refrigerant type and factory charge in ounces
Photograph the entire plate before closing the panel or walking away. The electrical specs matter when sizing a replacement contactor or fan motor; the refrigerant line matters if you suspect a leak or need to recharge after a repair.
If sun has faded the sticker, shine a flashlight across the surface at a shallow angle — the raised stamping underneath is usually still readable.
Symptom → failed component → York OEM Source 1 part
Five symptoms cover the vast majority of residential York AC service calls. Match the symptom first, then confirm the failed component, then look up the Source 1 part number against your model.
Symptom 1: Humming at the condenser, fan not spinning
Most likely cause: dual-run capacitor failure.
The dual-run capacitor is a cylindrical component (usually silver or black) mounted inside the condenser cabinet near the contactor. It stores the voltage spike that both the compressor and the condenser fan motor need to start. When it weakens or shorts out, the compressor hums under load but cannot overcome inertia, and the fan does not start.
How to confirm: with power off at the disconnect, discharge the capacitor by shorting its terminals with an insulated screwdriver, then test with a multimeter in capacitance mode. A capacitor rated 45/5 MFD that reads below 90 percent of either value is bad. Replace with a York OEM Source 1 dual-run capacitor matched to the printed ratings — both compressor microfarad (HERM terminal) and fan microfarad (FAN terminal), plus voltage.
A quality universal capacitor with matching MFD and voltage ratings also works — capacitors are commodity components. See the OEM vs aftermarket breakdown for which York parts are safe to swap with universals.
Symptom 2: Audible click at the contactor, no compressor start, no fan
Most likely cause: stuck, pitted, or burned contactor.
The contactor is a square or rectangular relay inside the condenser cabinet, usually with two large screw terminals on each side plus small 24V coil terminals. When the thermostat calls for cooling, the 24V coil pulls the contactor closed, sending line voltage to the compressor and fan.
How to confirm: with power on and the thermostat calling, measure line voltage across the contactor's load-side terminals. If the coil is energized but the contacts are not making a solid connection, you will see voltage dropping or arcing on one leg. Pit marks on the contact faces are a visible tell.
Replace with a York OEM Source 1 contactor matched to the amp rating and pole count on the data plate. Residential York ACs typically use 30A or 40A, 1-pole or 2-pole contactors. A quality universal of the same spec also works — this is another commodity component.
Symptom 3: Compressor running, condenser fan silent
Most likely cause: condenser fan motor failure, or the fan side of the dual-run capacitor is dead while the compressor side still works.
How to confirm: with power off, try to spin the fan blade by hand. If it is seized or has significant drag, the motor bearings are gone. If it spins freely but will not start on its own under power, test the fan side of the capacitor first (fan microfarad is the smaller of the two values printed on the capacitor — typically 5 MFD).
If the capacitor tests good and the motor still will not run, the motor is bad. York condenser fan motors are matched to the cabinet by horsepower, RPM, voltage, shaft diameter, and shaft length. All five have to match. The Source 1 part number is on a sticker on the motor shell — a string starting with S1- followed by 7 to 10 digits.
This is where OEM matters more than on capacitors or contactors. A universal fan motor with the wrong shaft length will not clear the fan grille or will leave the blade in the wrong plane relative to the coil, dropping airflow and raising head pressure.
Symptom 4: Breaker trips every time the AC tries to start
Most likely cause: locked-rotor compressor, or a short in the compressor windings.
A breaker trips because current exceeded its rating. On a startup trip, the usual culprits in order are: a dead capacitor letting the compressor stall under load (test first — cheapest fix), a welded contactor sending uninterrupted line voltage, a seized compressor pulling locked-rotor amperage until the breaker opens, or a shorted compressor winding to ground.
How to confirm: pull the compressor leads at the contactor with power off and measure resistance from each terminal to ground with a megohmmeter or a standard ohmmeter on its highest range. Infinite resistance to ground is good. Any reading indicates a short — the compressor is dead.
A compressor replacement on a York AC is the largest single part job on the unit: $1,500 to $3,000 for the Source 1 OEM compressor plus 4 to 6 hours of labor, plus refrigerant recovery and recharge. At that cost, run the repair-vs-replace calculus before ordering the part — a 12-year-old AC with a dead compressor is usually a replacement, not a repair.
Symptom 5: Nothing happens, power confirmed, breaker not tripped
Most likely cause: tripped high-pressure or low-pressure safety switch, blown low-voltage transformer, or a failed control board.
With power at the disconnect, measure 24V across the R and C terminals on the condenser's control board (or the contactor coil terminals on simpler units). No 24V means the transformer or the thermostat wiring upstream is the issue. 24V present but the contactor never pulls in means a safety has tripped (high-pressure switch is the most common — it opens on dirty coils, blocked airflow, or overcharge) or the control board itself has failed.
High-pressure switches are a $20 to $40 Source 1 part and a 15-minute replacement. Control boards are $200 to $600 and model-specific — use the York OEM Source 1 board every time. A universal board will not run the YXV inverter drive or the YZH variable-capacity logic, and installing one voids the parts warranty.
Diagnostic flowchart: from symptom to confirmed Source 1 part
The decision tree, in five steps:
- Confirm the symptom. Thermostat set to cool, 3 degrees below room temperature. Listen at the outdoor unit. Note what happens (or does not) in the first 60 seconds.
- Pull the model and serial. Photograph the data plate on the side of the cabinet. Record both M/N and S/N.
- Match symptom to component. Use the symptom chart above to narrow to the single most likely failed part.
-
Pull the Source 1 part number from the failed component. Capacitors, contactors, fan motors, boards, and safety switches all carry an
S1-sticker. That number is the shortest path to the exact replacement. - Cross-reference the Source 1 part against your unit's model number through the Johnson Controls parts catalog or HVACMORE at 855-575-4822. Confirm supersessions — York retires and renumbers Source 1 parts constantly, and the number on your 2019 motor may ship under a new SKU in 2026.
Decoding York AC model families: what each prefix tells you
Two or three letters at the start of the model number identify the family. Family changes the parts list more than any other character in the string.
- YXV — Affinity variable-capacity air conditioner, SEER2 up to 20, inverter-driven compressor, communicating control board. Parts: Source 1 inverter drive, Hx3/S1-THX communicating thermostat, modulating TXV. Not interchangeable with single-stage families.
- YXT — Affinity two-stage AC, SEER2 16 to 18, two-stage scroll compressor. Shares some parts with YXV (board family) but has a different compressor platform.
- YCG — LX single-stage air conditioner, SEER2 13.4 to 15.2, standard scroll compressor, non-communicating 24V control. The most common York AC in the field. Parts are the most commoditized — capacitors, contactors, and fan motors cross well to universals.
- YHE — LX heat pump family, single-stage, with reversing valve and defrost board added to the AC parts list.
- YZH — Affinity variable-capacity heat pump, SEER2 up to 20, HSPF2 up to 11, inverter drive, communicating thermostat. The Source 1 parts list is the longest of any York residential outdoor unit.
If you are shopping for a new York AC rather than repairing one, the Air Conditioner Buying Guide 2026 compares the York families against Goodman, Lennox, Trane, and Carrier equivalents.
Worked example: YCG4830A1 that will not start
Suppose a homeowner reports a York AC that will not start. The thermostat is calling, the breaker is not tripped, the disconnect has power. At the condenser they hear a loud hum but no fan movement.
Reading the data plate: YCG4830A1.
- YCG — LX single-stage air conditioner family
- 48 — 48,000 BTU/hr nominal = 4 ton
- 30 — generation code (SEER2 13.4)
- A1 — cabinet revision A, 208/230V single-phase
Symptom (hum, no fan) maps to failed dual-run capacitor. Open the service panel, discharge the capacitor, read the printed ratings. For a YCG4830A1 the factory capacitor is typically 45/5 MFD, 440V, Source 1 part number S1-02435862000 (the exact Source 1 number varies by cabinet revision — confirm against your unit).
Multimeter reads 32 MFD on the compressor terminal (should be 45), 4.1 MFD on the fan terminal (should be 5). Capacitor is bad. Order the York OEM Source 1 replacement, or a quality universal 45/5 MFD 440V capacitor. Install, close the service panel, restore power. Fan spins, compressor starts, cooling returns.
Total time: 20 minutes. Total parts cost: $25 to $45. The entire diagnosis hinged on three pieces of information: the symptom, the model number, and the capacitor ratings printed on the component itself.
Common York AC troubleshooting mistakes
Replacing the capacitor before testing it. A dual-run capacitor is only $25 so it is tempting to swap it as a first move. If the real failure is a seized compressor or a stuck contactor, the new capacitor will fail within minutes and the symptom returns. Test before replacing.
Ignoring the Source 1 part number on the failed component. The S1- sticker is a direct cross-reference to the exact OEM replacement, with no decoding needed. Reading the model number is only necessary to confirm supersessions — the Source 1 number does the heavy lifting.
Ordering by capacity alone. “3-ton York condenser fan motor” is not a part. The same 3-ton York AC uses different fan motors across generations and cabinet revisions. Order by Source 1 part number plus model confirmation, not by capacity.
Installing a universal control board. Boards are not commodity parts on York ACs. The YXV, YXT, and YZH boards run inverter and communicating logic that universal boards cannot replicate. Universal is fine on YCG and YHE boards for simple on/off operation — and even then, the parts warranty requires OEM for in-warranty replacements.
Skipping the warranty check. Johnson Controls warrants York residential equipment for 10 years on parts when the unit was registered within 90 days of install. If the AC is in warranty, call York or an authorized dealer first — the compressor or board may be free. Install a universal part during the warranty period and the warranty is void.
Forgetting about the indoor side. “AC not cooling” is not always an outdoor-unit problem. A dirty filter or a frozen evaporator in the air handler can look identical from the thermostat. Check the indoor side before assuming the condenser is at fault — the HVAC maintenance guide covers the airflow checks.
Frequently asked questions
Why won't my York air conditioner turn on? The most common cause is a failed dual-run capacitor. Other causes in order: a stuck or burned contactor, a tripped high-pressure safety switch, a tripped breaker, or a failed control board. Diagnose cheapest to most expensive — check the breaker, test the capacitor, test the contactor, then look at the board.
My York AC is humming but the fan is not spinning. What is wrong? Almost always a failed dual-run capacitor. The capacitor stores the voltage spike needed to start both the compressor and the condenser fan motor. Weak or shorted capacitor means the compressor hums under load without turning and the fan does not start. Replace with a York OEM Source 1 capacitor or a quality universal matched to the printed MFD and voltage ratings.
Why does my York condenser fan not run even though the compressor does? The fan side of the dual-run capacitor (smaller MFD value, typically 5) has failed, or the condenser fan motor itself is seized. Spin the blade by hand with power off — if it drags, the motor bearings are gone. If it spins freely, test the fan side of the capacitor.
My York AC trips the breaker when it starts. What is causing it? The unit is pulling locked-rotor amperage. Causes in order: dead capacitor letting the compressor stall, welded contactor sending uninterrupted voltage, seized compressor, or a shorted compressor winding. Test the capacitor and contactor first; if both are good, the compressor is likely the cause.
Why is my York air conditioner freezing up with ice on the lines? Evaporator temperature dropped below 32 F while the system kept running. Causes in order: dirty air filter or blocked return (airflow starvation), low refrigerant from a leak, or a failed TXV. Replace the filter, let the ice melt, restart. If it refreezes within hours, call a licensed technician for a refrigerant check.
How do I find the Source 1 part number on my York condenser fan motor? It is a sticker or stamp on the motor shell near the wiring leads, starting with S1- followed by 7 to 10 digits. If the label is unreadable, use the AC model and serial plus the motor's horsepower, voltage, and shaft dimensions to look up the current superseded part through HVACMORE.
Can I use a universal capacitor to replace a York dual-run capacitor? Yes. Match microfarad values on both compressor (HERM) and fan (FAN) terminals and match the voltage rating (370V or 440V). Universal is fine for capacitors; not fine for control boards, inverter drives, or ECM motors.
Can I use a universal condenser fan motor on a York AC? For older single-stage YCG and YHE units with simple PSC motors, a universal of matching HP, RPM, voltage, shaft diameter, and shaft length will work. For YXV, YXT, and YZH units with communicating or ECM motors, use the York OEM Source 1 motor only.
Where is the model number on a York air conditioner? On a silver data plate riveted to the side of the condenser cabinet, usually the side facing the house. Marked M/N for model and S/N for serial. See the York model number lookup guide for full decoding.
What does the YXV in a York model number mean? YXV is the York Affinity premium variable-capacity air conditioner family, SEER2 up to 20, with an inverter-driven compressor and a communicating control board. YXV parts are not interchangeable with single-stage York families.
Does HVACMORE sell OEM parts for York air conditioners? Yes. HVACMORE stocks York and Johnson Controls Source 1 OEM parts for every York residential AC family — capacitors, contactors, condenser fan motors, control boards, TXVs, pressure switches, and compressors. Fitment is cross-referenced against your model and serial before shipping. Call 855-575-4822 or send a photo of the data plate through chat.
Buying from HVACMORE
HVACMORE stocks York and Johnson Controls OEM parts for residential air conditioners, heat pumps, furnaces, and air handlers — from $25 capacitors and contactors to $2,500 inverter-driven compressors. Every Source 1 part number is cross-referenced against the model and serial you supply before the order ships, so you don't open the box and find the wrong SKU.
What ordering York OEM parts from HVACMORE gets you:
- Fitment verified against your York model and serial before the order ships
- Source 1 part number cross-check for supersessions and renumbered SKUs
- Free shipping on eligible orders over $500
- Price match if you find the same Source 1 part number cheaper elsewhere
- Original 10-year York parts warranty preserved when the unit is in-warranty and the replacement is OEM
- 60-Day Money Back Guarantee
- 30-Day Hassle-Free Returns with no restocking fees
Not sure which Source 1 part you need? Text or email a photo of the data plate and the failed component to the HVACMORE parts team, or call 855-575-4822 — US-based, Monday to Friday 8am–9pm ET, weekends included. Reading your York model and the Source 1 number off the failed part takes two minutes and prevents a wrong-part return.
The bottom line
A York air conditioner that will not start, will not cool, or trips the breaker is a decision tree, not a mystery. The symptom narrows the failure to one of five components. The data plate narrows the OEM replacement to one Source 1 part number. The
S1-sticker on the failed component itself is the shortest path — it bypasses the model-number decoding entirely. Pull the data plate photo, pull the Source 1 number off the dead part, and either verify fitment yourself through the Johnson Controls catalog or call HVACMORE with both strings in hand. OEM where it counts — boards, inverter drives, communicating thermostats, anything under warranty — universal where the physics are commodity. The $25 capacitor and the $25 universal are the same part. The $400 YXV board and the $90 universal board are not.
Sources
- Johnson Controls — York residential HVAC (product families, warranty terms, Source 1 OEM parts catalog)
- U.S. Environmental Protection Agency — SNAP program overview (refrigerant transition rules affecting 2024–2026 model generations)
- U.S. Department of Energy — Central Air Conditioning (SEER2 standards and efficiency definitions)
- ENERGY STAR — Central Air Conditioners (certification criteria for high-efficiency units)
- Related reading on HVACMORE — York Model Number Lookup & OEM Parts, York Furnace Flash Codes & OEM Parts, Repair vs Replace, Air Conditioner Buying Guide 2026
York residential AC parts, Source 1 part supersessions, and warranty terms change over time. Always verify current fitment with Johnson Controls, an authorized York dealer, or HVACMORE parts before ordering. Warranty registration windows and coverage vary by product generation. Any work involving refrigerant lines, high-voltage circuits, or sealed-system components should be performed by a licensed HVAC technician.
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