Ruud UGPH-07EAMGR Error Code LED Off: No Power to Control Board

What Does Code LED Off Mean?

The green "OK" status LED on the UTEC 1012-925 board is normally lit whenever the board has power. If it is completely dark, the board is not getting the 24VAC it needs and the furnace will not respond to the thermostat at all. There is no blinking fault code in this state because the board itself is unpowered and cannot signal one.

The most common reasons are the simplest: the furnace's own power switch (a wall-switch-looking disconnect on or near the unit) has been shut off, or the circuit breaker feeding the furnace has tripped. Both are homeowner-checkable. Beyond those, a failed low-voltage transformer — which steps the 115VAC line down to the 24VAC the board runs on — or a failed control board will also leave the LED dark and require a technician.

This is the opposite of the steady-on LED state on the same board, which indicates normal operation. Because there is no blink code to read, diagnosis works backward from the power source: line voltage, then transformer, then board.

One important safety note: if the breaker trips again the moment you reset it, stop. A repeatedly tripping breaker signals an electrical fault that needs a professional, not repeated resets.

What You'll Notice

• The control-board status LED is completely dark — no green light and no blinking
• The furnace does nothing when the thermostat calls for heat
• The blower, igniter, and draft motor are all silent
• The thermostat screen may be blank too, if it is powered from the furnace
• The furnace circuit breaker may be sitting in the tripped (middle) position

Common Causes

How This Is Diagnosed

Start with the two homeowner-safe checks: confirm the furnace power switch is on and that the circuit breaker has not tripped, since a bumped switch or tripped breaker is the most common cause of a dark board. If restoring those brings the LED back, you are done.

If the switch is on and the breaker holds but the LED stays dark, a technician measures line voltage to the furnace, tests the low-voltage transformer for 24VAC output, and checks the board. If 24VAC is present at the board but the LED is still off, the control board itself has failed and is replaced.

How to Fix It: Check the Power Switch and Circuit Breaker

What You'll Need

• Flashlight

Steps

1. Turn off electrical power at the breaker and shut off the gas supply valve Before inspecting anything, flip the furnace breaker fully OFF and turn the gas shutoff valve to the OFF position (handle perpendicular to the pipe). If you smell gas, leave immediately and call your gas company.
2. Confirm the furnace power switch is ON Find the switch on or near the furnace — it looks like an ordinary light switch and is sometimes mounted on the unit's side. Make sure it is in the ON position, since it can be bumped off or mistaken for a light switch.
3. Inspect the circuit breaker At your electrical panel, find the furnace breaker. If it is tripped (sitting in the middle), push it firmly to OFF, then back to ON. Note whether it stays set or trips again right away.
4. Restore power and gas, then check the LED With the power switch on and the breaker reset, turn the gas valve back to ON (handle parallel to the pipe) and restore breaker power. Watch the control board for the status LED to light.

When to Call a Professional

Contact a licensed HVAC technician if:

• The status LED stays dark after the power switch is on and the breaker is reset
• The circuit breaker trips again immediately or repeatedly (do not keep resetting it)
• You smell burning or see scorching near the furnace wiring or transformer
• The furnace has power at the switch but the board still shows no LED
• You are not comfortable working at the electrical panel

✓ Verified against manufacturer service manual — March 2026