Ruud U802VA050317MSA Error Code A225_F: Internal Fault: Gas Valve 1 Relay Welded Shut
What Does Code A225_F Mean?
A225_F on the Ruud U802VA means the Bluetooth Communicating IFC has detected that the relay controlling gas valve 1 (the primary valve) is welded shut — its contacts have fused together, most often from electrical arcing, and can no longer open. Because the relay cannot open, the control is unable to remove voltage from the gas valve; the valve stays commanded on regardless of what the control intends.
This is a combustion-safety hazard. A gas valve that the control cannot de-energize can allow gas to flow when it should be shut off, so this fault is treated as urgent. It is the welded-shut counterpart to A226_F (Gas Valve 1 Relay Stuck Open); the two are opposite failure modes of the same relay. With A226_F the valve can never be energized (no heat, but no gas hazard), whereas with A225_F the valve can never be de-energized (the hazard). On two-stage units the high-stage valve has its own equivalents, A227_F and A228_F. A welded gas-valve relay can also be reported under the general internal-fault lockout, A093_F.
The welded relay is integral to the IFC and cannot be repaired separately, so the board must be replaced. As a safety measure the manual gas shutoff to the furnace should be closed immediately and the furnace left off until a technician replaces the board, programs the new IFC over Bluetooth for the model, and verifies the gas-valve relays open and close correctly.
What You'll Notice
- The contractor app shows A225_F as a critical internal fault.
- The furnace is locked out, but the burners may behave unexpectedly.
- You may smell gas or notice the gas valve staying open when no heat is called.
- The fault does not clear by cycling power.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Welded relay contacts on control board | Most common | ✗ Call a pro → |
How This Is Diagnosed
A technician confirms A225_F in the Ruud contractor app and treats it as a gas-safety fault. After the manual gas supply is shut off, they verify that unexpected voltage is present at the gas-valve relay and that the relay will not open on command; because a welded relay cannot be serviced in the field, they condemn and replace the IFC, then program the new board over Bluetooth and confirm the relay opens and closes correctly before restoring gas.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The app reports A225_F, a welded gas-valve relay
- You smell gas or the burners stay lit when no heat is called
- The fault remains after power is cycled
- The furnace has been left off with the gas shut off pending board replacement
Frequently Asked Questions
Is A225_F dangerous?
Yes. The control can no longer shut off the primary gas valve, so gas can flow when it shouldn't. Shut off the gas supply to the furnace and leave it off until a technician replaces the board.
Can I just reset the furnace?
No. A welded relay is a physical hardware failure; cycling power will not fix it, and restarting the furnace is unsafe.
What repair does it need?
The IFC control board must be replaced and then programmed over Bluetooth for your model. The welded relay cannot be repaired on its own.
✓ Verified against manufacturer service manual — March 2026