Air-source heat pump outdoor unit beside a house in the snow
8 components covered

Field manual · Air Conditioner

Rheem / Ruud RA13, RA14, RA16 and RA14AZ/RA14AY single-stage AC condensers: quick sheet

Covers: Rheem Classic Series and Ruud Achiever Series single-stage split air conditioner outdoor units that share the RA model prefix. Ruud uses the same RA model numbers as Rheem (e.g. Ruud RA1448AJ1NB, RA1424XJ1NA). Model pattern: RA + efficiency class (13, 14, 16) + nominal capacity in kBtu/h (18, 24, 30, 36, 42, 48, 60) + revision/voltage letters, e.g. RA1424AJ1NA (2 ton), RA1636AJ1NA (3 ton), RA1336AJ1NA, RA1436AC1NB, RA1442BC1NB. The trailing NA/NB letters change with factory options (some listings tie NB to added high/low pressure switches; not confirmed by Rheem literature). SEER2-era successors: RA14AZ (R-410A, e.g. RA14AZ24AJ1NA, up to 16 SEER2 / 13 EER2) and RA14AY (R-454B, e.g. RA14AY18AJ1NA, RA14AY36AJ1NA). Search terms: RA14, RA16, RA13, RA1424, RA1636, RA14AZ, RA14AY, Rheem Classic condenser, Ruud Achiever condenser. Not researched here: RA17/RA15 two-stage or variable units, Ruud UA16AZ/UA16AY (inverter, variable-speed twin-rotary, a different platform), and the RP14/RP15/RP16 heat pumps (these add a defrost control, reversing valve and outdoor sensor; use the heat pump literature). Furnace/air handler side: see the Rheem/Ruud furnace quick sheet.

Cross-checkedBrands: Rheem, Ruud8 components

The RA13/RA14/RA16 condensers are conventional single-stage, cooling-only outdoor units: a scroll compressor, a PSC condenser fan motor, a dual run capacitor and a contactor pulled in by the thermostat Y call. There is no diagnostic control board or LED code display on these residential units, so diagnosis is done with a meter at the contactor, capacitor and motor terminals. Rheem markets the cabinet under the PlusOne name: a two-fastener removable corner panel for access to the electrical and compressor area, extra room around the service valves, and a diagnostic window for gauge-port access. RA14AZ and RA14AY are the newer SEER2-rated versions; the AY uses R-454B (A2L, mildly flammable), which changes service rules.

Safety first

  • Open the disconnect and verify 0 V before opening the control box; capacitors can hold a charge after power is removed.
  • All refrigerant work (gauges for charge, recovery, brazing, leak repair, compressor replacement) is blocked: refer to an EPA 608-certified technician.
  • RA14AY units contain R-454B (A2L, mildly flammable): no open flame or sparks near a suspected leak; refrigerant service needs A2L-trained technicians and tools.
  • Never jumper a pressure switch to keep the unit running.

How it works

The indoor unit (furnace or air handler) supplies 24 VAC. When the thermostat closes R to Y, 24 VAC reaches the contactor coil in the outdoor unit through any pressure switches fitted in series. The contactor closes and sends line voltage (208/230 VAC single phase on the J1 residential models) to the compressor and the condenser fan motor at the same time.

A single dual run capacitor serves both motors: the HERM terminal feeds the compressor start winding, the FAN terminal feeds the fan motor, and C is common. A weak capacitor shows up as a compressor that hums and trips on overload, or a fan that is slow to start.

Models fitted with pressure controls open the Y circuit if suction pressure falls too low (loss of charge, iced coil, failed indoor blower) or discharge pressure rises too high (dirty coil, failed fan). Auto-reset switches close again once pressure returns to normal; the unit restarts on the next call. Repeated trips point to an airflow or refrigerant problem.

When the call ends the contactor opens and both motors stop. Single-stage units have no compressor staging, so capacity is all-or-nothing; long run times in humid weather are normal.

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OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work. © 2026 OnCall Tech. Original content; not a reproduction of any manufacturer document.Generic part photos (not of this brand): Air-source heat pump outdoor unit beside a house in the snow by PeterEastern, CC BY-SA 4.0

Diagnostic guides for this appliance

Guide · Air Conditioner

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5 steps ~60 minmoderate
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PTAC error codes: how to read and clear them

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4 steps ~20 mineasy

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Goodman / Amana GSX air conditioner and GSZ heat pump outdoor units: quick sheet

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Trane XR14 / XR16 and American Standard Silver 14 / 16 outdoor AC and heat pumps (4TTR4, 4TTR6, 4TWR4, 4TWR6): quick sheet

Trane XR-series split outdoor units on R-410A: XR14 air conditioner 4TTR4 and heat pump 4TWR4 (1.5-5 ton, single-stage); XR16 air conditioner 4TTR6 and heat pump 4TWR6. Generation matters for the XR16: older 4TTR6 units (suffixes such as B or J, rated about 16 SEER) are single-stage; the 2023+ N-suffix units (e.g. 4TTR6036N1000A, 4TWR6036N1000A, up to 16.2 SEER2) are two-stage and are the former XR17 platform renamed XR16. American Standard equivalents: Silver 14 AC 4A7A4 (e.g. 4A7A4024N1000A) and Silver 14 heat pump 4A6H4 (e.g. 4A6H4048N1000A), both single-stage; 4A6H6 heat pump (older H-suffix Silver 16, single-stage); 4A7A6 AC stage count not confirmed. Also related: XR13 (4TTR3 / 4TWR3) single-stage. R-454B successors use a 5 prefix (5TTR4, 5TWR4, 5TTR6, 5A6H4, A5A6H6) and are not covered here. Search terms: 4TTR4, 4TTR6, 4TWR4, 4TWR6, XR14, XR16, Silver 14, Silver 16, 4A7A4, 4A6H4, 4A6H6.

8 components6 common failuresTrane, American Standard
Rheem / Ruud RA13, RA14, RA16 and RA14AZ/RA14AY single-stage AC condensers: quick sheet · OnCall Tech