FieldBench

Amana

ALXS4B

AC · R-32 single-stage · contactor + dual cap

Current Amana R-32 single-stage condensing unit. A2L. Same contactor physics as ASX16 — wrong refrigerant to top off from a 410A truck.

Not ASX16 (R-410A). Not ALXT7C two-stage. Not AXV9S inverter.

Maker PDFs

Walk this in Diagnose

This plate

Refrigerant
R-32 (A2L)
Stages
Single-stage scroll · contactor
Sister SKU
Goodman GLXS4B · ALXS4N multi-family

This board

Contactor + fan · R-32 nameplate

  • No outdoor 7-seg.
  • Rating plate R-32. 410A gauges and ASX16 targets are the wrong book.

Sequence

  1. Y. 24 VAC at the contactor coil → compressor and outdoor fan. Indoor blower on the cool tap / G.

Faults on this IFC

  • No Y

    Outdoor silent

    warn

    No 24 VAC at the contactor or the coil is open.

    • Y and C at the outdoor. Indoor IFC / stat actually closing Y.
    • Contactor coil ohms. Do not confuse a furnace lockout with a dead outdoor.
  • Hum / no start

    Cap / start

    lockout

    Compressor hums, outdoor fan may run.

    • Dual cap (fan and herm). Replace on values, not just a bulge.
    • Hard-start only after the cap and windings are proven.
  • HPS

    High pressure

    lockout

    Outdoor airflow, overcharge, or restriction.

    • Fan running? Coil dirty? SC vs nameplate on a TXV coil.
  • LPS / freeze

    Low pressure

    lockout

    Charge, indoor airflow, metering.

    • Do not add gas on a frozen coil. Indoor filter/coil first.

Workflows

No cool, ALXS4B

Plate says R-32.

  1. 24V Y, contactor, dual cap.
  2. R-32 recover / weigh / SC or SH on the R-32 coil match.
  3. Do not put 410A into this cabinet.

Test points

Charge
Nameplate + line-set. SH on piston, SC on TXV.
Cap
Dual can. Fan and herm both in spec.

Gotchas

  • Goodman GLXS4B is the twin.
  • ASX16 in the same yard is 410A.

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