Yorkac

YC2F

LX · two-stage condensing unit

York LX two-stage air conditioner (YC2F 15.2 SEER2 class). Y1/Y2. Not Affinity YXT and not the YC2E single.

Not YC2E single-stage. Not YXT Affinity two-stage. Not YXV inverter.

Diagnose this model Install notes Board cross-ref Field wiring

Stages

Two-stage · Y1/Y2

Control

24V Y1/Y2

Refrigerant

Read the plate — late YC2F may be R-454B

This board

LX two-stage — Y1/Y2, not Affinity communicating

High stage is Y2.
YXT is the Affinity two-stage with a different outdoor control story.

Live Y1/Y2 and pressures.

Universal swap

No universal

York YC2F outdoor. No furnace IFC universal. Replace the OEM outdoor control / contactor / drive by the silk.

Silk: YC2F

White-Rodgers

—

ICM

—

Honeywell

—

Indoor furnace universals (50A55, 50M56U, ICM282B, ICM2811, S9200U). This is not an IFC.
Do not ‘adapt’ a furnace board to an outdoor inverter, defrost PCB, or contactor.

After you pull the dead card

1Photograph the outdoor silk. Indoor 50A55 / ICM282B / S9200U do not belong here.
2Contactor units: replace the contactor / cap / HPS — there is no universal outdoor board.
3Inverter / communicating outdoors: OEM drive only. There is no White-Rodgers or ICM outdoor universal.

Field wiring

Written landings for York YC2F. Not a factory schematic.

Two-stage 24V · Y1 / Y2

Conventional Y1 / Y2 / CRead the nameplate

Two-stage scroll. High stage is Y2 at the outdoor. A single-stage stat never gets you there. Still not Infinity ABCD.

Written circuit description only — FieldBench does not redraw maker schematics. Example: R to W closes on a heat call; verify 24V at W1 before you change the IFC.

Open manufacturer PDF

This indoor

LX two-stage Y1/Y2. Not YXV Affinity.

24V two-stage

Outdoor has Y1 and Y2. Not an inverter drive.

Wall thermostat

Two-stage cool. A single-Y stat never pulls high.

R24V hot24V
C24V common24V
Y1Low-stage cool24V
Y2High-stage cool24V
GIndoor fan24V
WHeat. Stays at the indoor.24V

Indoor IFC / AHU

Y1 and Y2 both have to leave this cabinet on high.

RTransformer hot24V
CCommon — run it to the outdoor24V
Y1Low-stage in / out24V
Y2High-stage in / out24V
GBlower24V
W1Heat24V

Outdoor — Y1 / Y2

Low vs high is these two screws, not an inverter L-code.

Y1Low-stage request24V
Y2High-stage request24V
C24V common24V

Outdoor line

208/230 through the disconnect to the contactor line side.

L1LineLine
L2LineLine
GNDEquipment groundLine

Dual run capacitor

C / FAN / HERM on the can. An inverter outdoor does not have this part.

CCommon — both windingsCap
FANOutdoor fanCap
HERMCompressorCap

Landing

24VIndoor Rstat R · C throughout
~24 VAC
24VStat Y1indoor Y1outdoor Y1
Low-stage coil / request
24VStat Y2indoor Y2outdoor Y2
High-stage. Missing Y2 = stuck on low.
LineL1 / L2disconnect
208/230

Prove it

Y1 at the outdoor on a 1-cool call. Then Y2 on a 2-cool / staging call.
If Y2 never arrives, the outdoor is not weak — the stat, indoor IFC, or the Y2 wire is.

Do not

Do not hunt ABCD / L-codes. If you see an inverter, you are on 24VNA6 / 191VAN / XV18.
InteliSense ≠ Evolution ABCD.

Preferred / Performance / Elite two-stage land here. Bryant 187B Evolution two-stage does not — that one is ABCD.

Sequence

1
Y1
Low stage.
2
Y2
High stage.

Faults on this IFC

Step 1, then 2, then 3. Expected reading and the fail branch sit under each check.

HPS

High pressure switch open

lockout

Outdoor HPS opened — coil circuit is dead. Not an inverter pressure fault and not an L-code.

1 Let it cool, then read the drive LED
On York YC2F overcurrent / overheat is often a dirty coil, a failed OD fan, or a locked compressor — not a dead inverter. Clear airflow, confirm the OD fan, and read the drive LED before you order a control. HPS continuity, reset if manual, wiring in series with the coil.
Expect: OD fan running. Coil clean. Drive LED decoded from THIS outdoor’s card.
2 Voltage and compressor windings
Incoming voltage in range (this plate’s line-voltage code). Compressor windings even, no ground. A shorted compressor will kill a new drive. Outdoor airflow: dirty coil, bent fins, fan not running (see ODF / cap).
Expect: Balanced windings. No winding to ground. Line voltage stable under load.
3 Charge and the drive last
A starved or flooded compressor will overcurrent. Confirm SH/SC and charge weight. Only then condemn the inverter. Overcharge or non-condensables — confirm indoor metering before you recover (SH vs SC).
Expect: Charge on the nameplate. Drive code gone after a cool-down and a clean coil.

ODF

Outdoor fan fail

warn

Fan not turning. Compressor may still run and then HPS.

1 Heat rejection first
On York YC2F high pressure is outdoor airflow until proven otherwise. Fan running the right direction, coil clean, fins not folded, no recirc over a fence or through a garage. Dual-cap FAN section µF vs sticker. A good HERM and a dead FAN is the usual Comfort call.
Expect: OD fan on, coil clean, discharge air leaving the top/side freely.
2 Head, subcooling, and liquid line
Liquid pressure and liquid-line temperature → SC. High head + high SC = overcharge or non-condensables. High head + low SC = restriction or a dying compressor. Do not add gas because suction is low. Fan motor ohms / ground, blade clearance, capacitor wiring (C / FAN / HERM).
Expect: SC vs the metering device on this plate (TXV ≠ piston).
3 Restriction vs the switch
Drier, liquid-line kink, TXV inlet screen, or a non-feed indoor coil will stack head. Ohm / jumper-test the HPS only as a momentary prove, then restore it. A switch that opens on a known-good charge and clean coil is the switch. Not an inverter fan module — there isn’t one.
Expect: HPS closed at a normal liquid pressure for this refrigerant and OD ambient.

Contactor

Contactor / coil

warn

Will not pull, chatters, or is welded.

1 Is Y actually at the contactor?
On York YC2F a silent outdoor is often no Y. Measure 24 VAC coil-to-C at the contactor on a cool call. 24 VAC at the coil under a Y call. Low voltage = long stat wire, weak indoor transformer, or a furnace 24 (fuse) problem.
Expect: ~24 VAC at the coil when the indoor is calling.
If fail: Indoor Y / IFC / stat — not a capacitor.
2 Cap and the compressor windings
Dual run cap: herm and fan MFD ±6%. Then windings. A bad cap with a good Y is still the first cheap part — but confirm MFD, do not guess. Coil ohms / burned turns. Pitted or welded points — replace, do not file and leave.
Expect: MFD on the can. Even windings. Fan and compressor both try.
3 Contactor and mechanical
Pitted contactor, no mechanical close, or a welded contactor that never drops out. Replace the failed part; do not file contacts as a repair. Chatter: low 24V, bad coil, weak transformer — not an inverter ramp.
Expect: Clean pull-in. Line voltage through to both loads.

Cap

Dual run capacitor

warn

HERM and/or FAN section out of rating. Single-stage Comfort dies this way all summer.

1 Is Y actually at the contactor?
On York YC2F a silent outdoor is often no Y. Measure 24 VAC coil-to-C at the contactor on a cool call. Both sections vs microfarad rating, not just one.
Expect: ~24 VAC at the coil when the indoor is calling.
If fail: Indoor Y / IFC / stat — not a capacitor.
2 Cap and the compressor windings
Dual run cap: herm and fan MFD ±6%. Then windings. A bad cap with a good Y is still the first cheap part — but confirm MFD, do not guess. Bulged can, open bleed, wrong replacement (single vs dual, voltage).
Expect: MFD on the can. Even windings. Fan and compressor both try.
3 Contactor and mechanical
Pitted contactor, no mechanical close, or a welded contactor that never drops out. Replace the failed part; do not file contacts as a repair. Hard-start add-ons do not fix a dead FAN section.
Expect: Clean pull-in. Line voltage through to both loads.

Charge

Charge (SH piston / SC TXV)

warn

Wrong charge method is as common as wrong charge.

1 Airflow and freeze before you add gas
On York YC2F low pressure / freeze is indoor airflow or a starved coil until proven otherwise. Filter, blower, dirty A-coil, closed supplies. In heat mode, a iced outdoor coil is the same family. Indoor piston: charge by superheat. Indoor TXV: charge by subcooling.
Expect: Indoor air moving. Coil not iced. OD coil clear in heat.
2 SH / SC after a thaw
Thaw fully. Then SH and SC vs the metering device. Low charge ices a piston. A TXV stuck closed ices with high SH. A restriction downstream of the ports fakes a low-charge chart. Do not use Greenspeed weigh-in-only as the only method unless the factory TXV rating plate on THIS outdoor says so. Most 24ACC are piston/TXV conventional.
Expect: SH/SC in range for this refrigerant and device after a stable 10-minute run.
3 Leak, TXV, then the LPS
Weigh-in if the chart says undercharge. Soap / electronic leak on joints and the coil. LPS that opens on a known-good charge and a clear coil is the switch — momentary test only, then restore. Line-set length and indoor coil match still matter. Weigh-in after a repair, then finish on SH or SC.
Expect: Charge on the nameplate. LPS closed at a normal suction for this OD ambient.

Workflows

YC2F stuck on low

Y2 never arrives.

1 Prove the call and the live code
Prove Y2 at the outdoor.
Expect: Write whatever LX two-stage — Y1/Y2, not Affinity communicating is showing. Live Y1/Y2 and pressures.
If fail: No call at the IFC → stat / harness. Do not change gas parts.
2 Isolate the first failed step in the sequence
Charge on the plate refrigerant.
Expect: Y2: High stage.
3 Confirm with a number, then the next part
This is not YXV. There is no inverter.
Expect: Contactor coil: Stable ~24 VAC on Y. Chatter = voltage, coil, or HPS. No ABCD to probe. · Dual cap: HERM and FAN both within ~6% (or OEM) of the stamped µF.
If fail: Stay on this plate. The out-of-range reading is the part.
If pass: Reading in range → the next step in this workflow is the repair.

Test points

Contactor coil

Stable ~24 VAC on Y. Chatter = voltage, coil, or HPS. No ABCD to probe.

Dual cap

HERM and FAN both within ~6% (or OEM) of the stamped µF.

Charge

SH target on piston indoor; SC target on TXV indoor. Weigh-in is a start, not a Greenspeed-only finish.

HPS

Closed at rest. Open under high head = airflow/charge, not an inverter L-code.

Gotchas

YXT looks like ‘the two-stage York’ on an invoice. Affinity ≠ LX.

Related plates

Install this plate

Install York YC2F as LX · two-stage condensing unit.

LX · two-stage condensing unit

This plate — not the sister SKU

Not YC2E single-stage. Not YXT Affinity two-stage. Not YXV inverter.
YXT looks like ‘the two-stage York’ on an invoice. Affinity ≠ LX.

Control on this outdoor

High stage is Y2.
YXT is the Affinity two-stage with a different outdoor control story.

Hardware

Stages: Two-stage · Y1/Y2
Control: 24V Y1/Y2
Refrigerant: Read the plate — late YC2F may be R-454B

First fire

1Prove Y2 at the outdoor.
2Charge on the plate refrigerant.
3This is not YXV. There is no inverter.

Do not on York YC2F

Not YC2E single-stage. Not YXT Affinity two-stage. Not YXV inverter.
YXT looks like ‘the two-stage York’ on an invoice. Affinity ≠ LX.

Maker literature

FieldBench does not host manufacturer files. Each link opens the maker’s own literature page in a new tab.

York residential gas furnacesLiterature searchTM9 / TM8 family listing (Coleman / Luxaire share the JCI IFC). UPGNet holds the I/O.Open manufacturer PDF
York / Bosch Home ComfortLiterature searchSearch York YC2F on the maker’s literature page.Open manufacturer PDF

Warranty and bulletins

Affected models, serial range, symptom, remedy, date. Maker files open on the manufacturer site.

All bulletins

Residential limited warranty
dealer
York furnace warranty
Registered TM8 / TM9 furnace warranty · Dealer claims portal
Open facts Open manufacturer PDF
Dealer portals
dealer
Where remaining service letters live
Current-year service letters not on a public literature page · Maker dealer portal
Open facts Open manufacturer PDF