Product Overview
The ADP 76722700 Control Board is a critical component designed for use in unit heater systems. It manages the operational functions of the heater, ensuring proper ignition, flame sensing, and safety shutdowns. This board is a direct replacement for part number 65312200.
Image: The ADP 76722700 Control Board, showing various electronic components, relays, and connection terminals. This board is essential for regulating the functions of a unit heater.
Safety Information
Always prioritize safety when working with electrical components and heating systems. Failure to follow these instructions could result in property damage, personal injury, or death.
- Ensure power to the unit heater is completely disconnected at the main breaker before beginning any installation or maintenance.
- Only qualified technicians should attempt installation or repair of this control board.
- Verify all wiring connections are secure and correct according to the unit heater's wiring diagram.
- Protect the control board from static discharge during handling.
Setup and Installation
This section outlines the general steps for replacing or installing the ADP 76722700 Control Board. Refer to your specific unit heater's service manual for detailed wiring diagrams and procedures.
- Power Disconnection: Turn off all electrical power to the unit heater at the main circuit breaker or fuse box. Confirm power is off using a voltage tester.
- Access Control Panel: Open the access panel of the unit heater to expose the existing control board.
- Document Wiring: Carefully photograph or sketch the existing wiring connections to the old control board. Label each wire if necessary.
- Disconnect Old Board: Disconnect all wires and mounting screws from the old control board. Remove the old board.
- Install New Board: Mount the new ADP 76722700 Control Board in the same location using the appropriate screws.
- Connect Wiring: Reconnect all wires to the new control board according to your documentation and the unit heater's wiring diagram. Ensure all connections are firm and correct.
- Secure Panel: Close and secure the unit heater's access panel.
- Restore Power: Restore electrical power to the unit heater.
- Test Operation: Initiate a heating cycle to verify proper operation of the unit heater and the new control board.
Operating Principles
The ADP 76722700 Control Board is designed to automate the ignition and operation sequence of a unit heater. Upon a call for heat from the thermostat, the board initiates the following sequence:
- Pre-purge: Activates the inducer motor to clear the combustion chamber.
- Ignition: Energizes the igniter (hot surface igniter or spark igniter) and opens the gas valve.
- Flame Sensing: Monitors for flame presence using a flame sensor. If flame is detected, the gas valve remains open. If not, the board attempts re-ignition or enters a lockout state.
- Blower Activation: Once the heat exchanger reaches a sufficient temperature, the main blower fan is activated to distribute heated air.
- Post-purge: After the thermostat call for heat ends, the gas valve closes, and the blower continues to run for a short period to dissipate residual heat.
The board also incorporates safety features, such as monitoring limits and pressure switches, to ensure safe operation and shut down the system if abnormal conditions are detected.
Maintenance
The ADP 76722700 Control Board itself requires minimal maintenance. However, regular maintenance of the overall unit heater system is crucial for the longevity and proper functioning of all components, including the control board.
- Annual Inspection: Have a qualified HVAC technician inspect your unit heater annually. They can check electrical connections, clean components, and verify proper operation of the control board and associated sensors.
- Cleanliness: Ensure the area around the control board and within the unit heater is free from dust, debris, and moisture, which can interfere with electronic components.
- Wiring Integrity: Periodically check for loose or corroded wiring connections to the control board. (Ensure power is off before checking connections.)
Troubleshooting
If your unit heater is not functioning correctly, the control board may provide diagnostic codes (e.g., flashing LED lights). Consult your unit heater's specific service manual for a list of diagnostic codes and their meanings. Below are general troubleshooting steps:
| Symptom | Possible Cause | Action |
|---|---|---|
| Heater not starting | No power, faulty thermostat, safety switch open, igniter issue | Check power supply, thermostat settings. Inspect safety switches (limit, pressure). Check igniter and flame sensor. |
| Blower runs continuously | Stuck fan relay on board, faulty fan limit switch | Consult a technician. May indicate a board issue or a faulty fan control. |
| Heater cycles on/off rapidly (short cycling) | Overheating (dirty filter, blocked vents), faulty limit switch | Check air filters and vents for obstructions. Inspect limit switch. |
| No ignition/No flame | No gas supply, faulty igniter, dirty flame sensor, faulty gas valve | Verify gas supply. Clean flame sensor. Test igniter. Consult a technician for gas valve issues. |
Note: Many issues related to the control board require diagnostic tools and expertise. If you are unsure, contact a certified HVAC professional.
Specifications
| Attribute | Detail |
|---|---|
| Brand | ADP |
| Model Number | 76722700 |
| Replacement For | 65312200 |
| Item Weight | Approximately 8.8 ounces (0.25 kg) |
| Product Dimensions | Approximately 10 x 10 x 2 inches (25.4 x 25.4 x 5.08 cm) |
| Manufacturer | ADP |
| Date First Available | April 29, 2010 |
Warranty and Support
Specific warranty information for the ADP 76722700 Control Board is typically provided by the seller or the manufacturer at the time of purchase. Please retain your proof of purchase for warranty claims.
For technical support or inquiries regarding this control board, it is recommended to contact the manufacturer, ADP, or a certified HVAC professional. They can provide guidance specific to your unit heater model and installation.
Manufacturer: ADP
Note: Contact information for ADP may be found on their official website or through your product supplier.
