ICP Defrost Control Board for YJ048G2 — Heat Pump | Ships Today
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Overview
This is a genuine OEM defrost control board (Part Number 34332101) for the ICP / Heil / Tempstar YJ048G2 heat pump. The defrost board governs the outdoor unit's heat-pump operation — it reads the defrost thermostat and timer, drives the reversing valve and compressor contactor, and periodically reverses the refrigerant cycle to melt frost off the outdoor coil during heating. When this board fails, the outdoor coil ices over, heating output collapses, and the compressor can lock out. Common failure signs include the coil staying frozen in heat mode, no defrost cycle ever starting, the unit failing to switch between heat and cool, or burnt relays and scorch marks on the board.
Specifications
| Spec | Value |
|---|---|
| Part Number | 34332101 |
| Type | Defrost Control Board |
| Brand | ICP (Heil / Tempstar / Comfortmaker) |
| Function | Heat-Pump Defrost Timing & Reversing Valve Control |
| Control Voltage | 24V |
| Fitment | OEM |
Compatibility
Designed as a direct OEM replacement for the ICP/Heil/Tempstar YJ048G2 heat pump and related ICP-family outdoor units using this defrost board. Verify the original board part number and connector layout before installing.
Installation Guide
- Safety First — Disconnect power at the outdoor disconnect and breaker, then verify zero voltage with a multimeter.
- Access — Remove the condenser/heat-pump electrical access panel.
- Document — Photograph every wire harness, plug, and terminal on the existing board before disconnecting.
- Remove — Unplug the connectors, release the board standoffs or screws, and lift out the old board.
- Install — Seat the new board on the standoffs and reconnect each harness to the matching terminal per your photos.
- Test — Restore power, initiate a defrost (or jumper the test pins per the board legend), and confirm the reversing valve and compressor respond correctly.
Signs You Need a Replacement
- Outdoor coil ices over in heat mode and never defrosts.
- No defrost cycle initiates regardless of outdoor temperature.
- Unit won't switch the reversing valve between heating and cooling.
- Visible burnt relays, melted connectors, or scorch marks on the board.
Shipping & Returns
Ships same day before 3 PM CST. 30-day returns. National HVAC Parts fitment guarantee.
Shipping Information
- Orders placed before 3PM CST ship same business day
- Standard delivery: 2-5 business days
- Express shipping available at checkout
- Free shipping on orders over $75
- Tracking number emailed upon shipment
Return Policy
- 30-day returns on unused parts in original packaging
- Electrical parts (capacitors, contactors, control boards) are final sale once installed
- Email info@nationalhvacparts.com to initiate a return
- Refunds processed within 5-7 business days