HEAT Annunciator ON, Relay Pack LED NOT LIT - Supplemental heat not energized

What does HEAT Annunciator ON, LED NOT LIT mean?

The slave thermostat's 'HEAT' annunciator is illuminated, indicating a heating demand, but the LED on the associated HR-03 Relay Pack is not lit. This suggests that the supplemental heat source is not being energized, potentially due to a problem with the damper actuator or the relay pack itself, despite the system controller calling for heat.

• Incorrect system mode selection by the system controller (e.g., system controller in heating mode, but supplemental heat not intended).
• Insufficient voltage from the damper actuator output to the relay pack.
• Faulty damper actuator circuit board.
• Defective HR-03 Relay Pack.

Click steps to track your progress.

1. 1

   Verify the slave thermostat's associated system controller is correctly configured for a heating mode that should energize supplemental heat.

2. 2

   At the damper actuator, unplug the relay pack and check the DC voltage between PIN 1 (common) and PIN 5 (H1); it should be 7.5 to 9.5 VDC steady.

3. 3

   If the slave thermostat zone demand is >= 2.0°F, verify the voltage between PIN 1 and both PIN 5 (H1) and PIN 6 (H2) is the same. If not, replace the damper actuator circuit board.

4. 4

   With the relay pack plugged in, check the DC voltage across the relay pack input connector plug (between the black wire and the appropriate input wire); it should be 4 to 6 VDC steady. If not, replace the relay pack.