Problem:
Per UL any gas heat burner over 500 MBh must have its own supply air proving detection that is independent of the unit's controller based fan proving input.
Issue:
Pressure switch closes at 0.20 iwc and if the duct static pressure is low the unit control module will generate a E09 alarm on the VB1285 (modulating burner controller) or a "53" flash code on the VB1287 (staged burner controller). This diagnostic has been noticed at unit start up commonly, if a panel has been removed to burn oil processing oil from the heat exchanger or SZVAV applications were the operating duct static pressures are generally pretty low.
Solution:
- Verify with squeeze bulb or ramp the supply fan up to test operation of the proving switch. Should close at 0.20 iwc. Field Calibration may be needed.
- On SZVAV applications and Symbio 800 firmware version is 1.30.008 or higher, increase the Heating Min Discharge Air Flow Setpoint in service settings until proving switch closes. The unit will have to be powered cycle after each service settings change for the new parameter will go into effect.
- On MZVAV, T&B more than likely has not been completed and VAV boxes are wide open and NOT in their set Max Open positions.
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.