Tempstar Defrost Control Board for TCH442AKA1 — Heat Pump | Ships Today
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Overview
This OEM defrost control board (Tempstar part #1086070) is the brain of the outdoor unit on your TCH442AKA1 heat pump. It monitors the defrost thermostat and outdoor coil temperature, times the defrost interval, and commands the reversing valve, compressor, and fan to clear frost from the outdoor coil during cold-weather operation. It also coordinates the contactor and any auxiliary/emergency heat staging. When this board fails, the heat pump may never defrost (ice builds on the outdoor coil), defrost too often and waste energy, fail to switch between heating and cooling, or lose outdoor unit operation entirely. Because the board interfaces with nearly every major component, a faulty defrost board often mimics other failures — confirm with the unit's diagnostic LED flash codes before replacing.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1086070 |
| Type | Defrost Control Board |
| Brand | Tempstar |
| Control Voltage | 24V |
| Application | Heat Pump Outdoor Unit |
| Fit | OEM Replacement |
Compatibility
Designed for the Tempstar TCH442AKA1 heat pump and used across matching ICP / Tempstar / Heil / Comfortmaker heat pump condensers that share this defrost control platform. Match the board's part number and connector layout to your existing board before installing.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker; verify zero voltage at the board with a multimeter.
- Access — Remove the outdoor unit's electrical control panel to expose the board.
- Document — Photograph every wire and plug connection; note the defrost timing pin/jumper setting.
- Remove — Unplug each connector, release the board's mounting standoffs/screws, and lift it out.
- Install — Mount the new board, set the defrost timing jumper to match the original, and reconnect every plug per your photo.
- Test — Restore power, initiate a forced defrost (per the board's test pins), and confirm proper defrost, mode switching, and LED status.
Signs You Need a Replacement
- Outdoor coil ices over and never goes into defrost
- Unit defrosts too frequently or gets stuck in defrost
- Heat pump won't switch between heating and cooling
- Diagnostic LED shows a board fault or no outdoor unit operation
Shipping & Returns
Ships same day on orders placed before 3 PM CST. 30-day hassle-free returns. Backed by the 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