Modine Manufacturing HD Manual page 145

Call for Heat – Unit Does Nothing
The below troubleshooting steps refer to situations where the green light on the control
board is OFF:
Step 1: If the green light on the control board is off, verify there is not a flash code.
Step 2: Verify that there is 24 VAC between Sec & Com on the control board.
• If 24 VAC is not present between Sec & Com, turn to page 10 for further
troubleshooting steps.
Step 3: Check the fuse for a blown element:
• Remove the fuse
• Check for continuity
• If fuse is blown, replace fuse
• If fuse is not blown, then the terminal board in not letting 24 VAC through the
board. If this is the case, please refer to page 23 to see troubleshooting steps
to take before replacing the control board.
Step 4: Check for loose connections.
GREEN LIGHT SEC & COM TERMINALS FUSE
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