Rheem RGPH-07EAMGR Error Code 4 Blinks (2-sec pause): Pressure Switch Shorted
What Does Code 4 Blinks (2-sec pause) Mean?
Before the induced-draft blower starts, the UTEC 1012-925 IFC expects the pressure (air-proving) switch to be open, proving there is no false draft signal. Four blinks then a 2-second pause tell you the board found that switch already closed — "shorted" — at a point in the sequence when it should be open.
A switch that reads closed before the inducer runs cannot be trusted to confirm real draft, so the board halts for safety. The most common reason is a failed pressure switch stuck in the closed position. Water or condensate trapped in the switch or its hose can also hold the contacts closed, and less often a wiring short between the switch terminals mimics the same condition.
This is the opposite fault from the pressure switch open code (2 blinks), where the switch never closes and often points to a blocked vent or weak draft you can start checking yourself. A shorted switch (4 blinks) is a stuck-closed component condition that the manufacturer directs to be corrected by replacing the switch — component-level work outside safe DIY.
What You'll Notice
- The status LED repeats four blinks then a 2-second pause and the furnace will not start.
- The furnace does not begin its normal inducer-then-ignition sequence at all.
- The fault appears immediately on a call for heat rather than after the inducer runs.
- You may see moisture or condensate near the pressure switch or its hose.
Common Causes
How This Is Diagnosed
A technician confirms the code, then checks the pressure switch state with a meter at rest — it should read open before the inducer energizes. If it reads closed with no draft present, the switch is shorted. The tech inspects the switch and its hose for trapped water or condensate that could hold the contacts closed, checks the wiring between the switch terminals for a short, and replaces the pressure switch if it has failed closed. This work is part of the furnace's safety draft-proving circuit and is not a homeowner repair.
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 four-blink code is present and the furnace will not begin its startup sequence
- You see water or condensate collecting in the pressure switch or its hose
- The code appeared after recent service or wiring work near the switch
- The furnace alternates between the four-blink code and no response at all
Frequently Asked Questions
What is the difference between pressure switch 'open' and 'shorted' on my Rheem?
Open (two blinks) means the switch never closed, often from a blocked vent or weak draft. Shorted (four blinks) means the switch is stuck closed when the board expects it open, which usually means the switch itself has failed and needs replacement.
Can I fix a shorted pressure switch myself?
No. The manufacturer directs replacing the switch, and it is part of the furnace's safety draft-proving circuit. Diagnosing and replacing it should be done by a qualified HVAC technician.
Could moisture cause this code?
Yes. Water or condensate trapped in the switch or its hose can hold the contacts closed and trigger the shorted reading. A technician will clear or replace the affected parts.
Sources
✓ Verified against manufacturer service manual — March 2026