Ruud UGRA-07EMAES Error Code 2 Blinks: Pressure Switch Open
What Does Code 2 Blinks Mean?
Before lighting, the IFC starts the induced draft motor (IDM) and waits for the pressure switch to close, proving that the inducer is pulling a draft and the flue is clear. If the switch doesn't close within 60 seconds, the board flashes two blinks, stops the inducer for 5 minutes, then retries the whole sequence.
On this single-stage furnace there is one pressure switch and one draft level to prove, so the check is simply pass or fail. The most common reason the switch won't close is a blocked or restricted vent or flue — snow, ice, a bird nest, or debris at the outdoor termination — which prevents the inducer from building the draft the switch needs. A cracked, kinked, or water-filled pressure-switch hose, a failing inducer motor, or the switch itself can also keep it open.
This 2-blink "open" fault is the opposite of the 4-blink "shorted / stuck-closed" fault on the same board: here the switch never closes when it should, while a 4-blink means it never opens when it should. Because the sequence halts before ignition, you won't hear the burners attempt to light at all, which distinguishes it from the 1-blink ignition lockout where the igniter and gas valve do try.
What You'll Notice
- No heat; the furnace starts its inducer but never advances to lighting the burners.
- The inducer runs for about a minute, stops for roughly five minutes, then tries again.
- A repeating two-blink pattern on the status LED.
- In cold or snowy weather, a visibly blocked or frosted-over exhaust or intake termination outside.
- No burner ignition sound at all during the failed cycles.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Blocked vent or flue pipe | Most common | ✗ Call a pro → |
| Faulty pressure switch | Common | ✗ Call a pro → |
| Failed induced draft motor | Uncommon | ✗ Call a pro → |
How This Is Diagnosed
Diagnosis starts at the vent, because a blockage is the most common and cheapest cause: the exhaust and intake terminations are checked outside for snow, ice, nests, or debris, and the vent pipe is inspected for sags that hold condensate. Next the pressure-switch tubing is checked for cracks, kinks, or trapped water, and the inducer is verified to be spinning and actually pulling a draft.
If the vent, hose, and inducer are all good, the technician measures the switch to confirm it closes at the correct pressure and checks that roughly 113-115 VAC is reaching the inducer motor. The switch or motor is then replaced based on those readings. Checking the outdoor termination for a blockage is something a homeowner can safely do, but the switch and motor testing needs a professional.
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 two-blink pattern continues after the outdoor vent and intake are confirmed clear
- The inducer does not run, or runs but never advances to ignition
- There is water or a cracked hose visible at the pressure switch
- The vent pipe sags or has sections holding condensate
Frequently Asked Questions
What does 2 blinks mean on a Ruud UGRA?
The pressure switch didn't close, so the board can't confirm the furnace is venting safely. It stops the inducer for five minutes and retries. A blocked vent is the usual cause.
Can I clear the vent myself?
You can safely check the outdoor exhaust and intake terminations for snow, ice, nests, or debris. Anything involving the pressure switch, its hose, or the inducer motor should go to a technician.
Why does my furnace start, then stop after about a minute?
The inducer runs first to prove venting. If the pressure switch doesn't close within 60 seconds, the board shuts the inducer down for about five minutes before retrying.
Is it safe to run the furnace with a 2-blink code?
The code is a safety interlock that prevents ignition without proven venting, so the furnace won't fire. Don't bypass the switch — have the vent and switch checked.
Sources
✓ Verified against manufacturer service manual — March 2026