Rheem furnace 2 blinks: Pressure switch did not close within 10 seconds
The inducer started but the pressure switch did not close within ten seconds. The inducer keeps running and waits, so the furnace sits there blowing without ever lighting.
- Pressure switch failure — switch remains open — Rheem standard gas furnaces
Applies to: Rheem, Ruud and Weather King *RC 92+ full size upflow and *RL 90+ full size downflow condensing furnaces, per installation instructions 708503a.
What it means
After the control energises the inducer it expects the pressure switch to close, proving the inducer is genuinely moving air and the vent is clear. Rheem's instructions give a specific window: if the switch does not close after ten seconds the fault LED blinks twice repetitively, and the inducer continues to run until the switch closes. That last detail explains what a homeowner actually sees, which is an inducer that runs indefinitely with no ignition and no lockout. The furnace is not stuck; it is waiting, indefinitely, for a signal that is not coming. This is the one blink count that means the same thing on both Rheem code lists.
Most common causes
- A blocked vent or intake termination outside — snow, ice, a nest, or a cap left in place. This is the most common cause in cold weather.
- Water in the pressure switch hose or in the condensate trap.
- A blocked condensate drain backing water into the collector box.
- A cracked, kinked or disconnected pressure switch hose.
- An inducer spinning but not developing enough suction, often from worn bearings or a dirty wheel.
- A failed pressure switch.
How to diagnose it
- Look at the vent and intake terminations outside for anything blocking them. This is homeowner work and it resolves a large share of these.
- Note whether the inducer sounds normal, weak, or noisy — a failing inducer often sounds different before it fails outright.
- Note whether there is standing water near the furnace, which points at a blocked condensate path.
- Note that this code behaves the same way on Rheem's standard furnaces, so the model check matters less here than on the other counts.
How to fix it
- Clear the vent or intake termination if it is blocked.
- Everything inside the cabinet — hoses, collector box, condensate trap, inducer, switch — is technician work.
- Do not jumper the pressure switch to force the furnace to fire. That interlock is what stops the furnace burning gas when the flue is not clear.
Do it yourself or call someone
The homeowner jobs are the outdoor ones: clear the vent and intake terminations, and look for standing water near the furnace that would point at a blocked condensate path. The ten-second spec on this control also hands the homeowner one unusually useful thing to report. Because the control waits indefinitely rather than locking out, the symptom is an inducer that runs continuously while the furnace never once tries to light — and saying exactly that to a service dispatcher identifies the pressure switch circuit before anyone opens the cabinet, which is the kind of description that gets the right part on the truck. Inside the cabinet, leave it alone: the hoses, the collector box, the condensate trap, the inducer and the switch itself are technician work, and jumpering the switch to force ignition removes the only proof that combustion gases are actually leaving the house.
Notes
Two blinks is the only count where Rheem's standard list and the condensing furnace instructions agree. Both describe a pressure switch that will not close.
Related
- 3 blinks — Pressure switch closed when it should be open
- Which blink code list applies — Rheem publishes two blink code lists that contradict each other
All codes for this manufacturer
Rheem, Ruud and Weather King furnace blink codes — every code, with what differs between models.
Not sure this is your brand?
The same count means something else on other furnaces. What 2 flashes means on every brand puts them side by side.
The same fault on other brands
A pressure switch that fails to close after the inducer starts is defined almost identically across control families, several of them with their own timing windows. Allied's -02 control (Armstrong, AirEase, Concord, Ducane) shows nine flashes, the ICP SmartValve furnaces (Heil, Tempstar, Comfortmaker) show three flashes, Lennox communicating systems raise alert 223, and Trane's S9V2 displays E32. What the *RC/*RL control does differently from most of those is the aftermath: it waits with the inducer running instead of locking out, which is why the symptom here is continuous blowing rather than a dead furnace.
What the fix costs
The cheapest and most common fix — clearing snow, ice or a nest off the terminations — is free, which is worth remembering before booking a cold-snap emergency visit. Paid outcomes, per the furnace repair cost guide: a pressure switch replacement runs $150–400, with the guide's caveat to rule out a blocked flue before blaming the switch, and an inducer that spins without developing suction runs $300–900 to replace, brand parts availability driving the spread — the inducer motor codes hub covers how that failure presents across brands. Condensate trap and hose work usually lands inside an ordinary service call at $75–150, often credited against a larger repair. After-hours calls add $100–200, which is another argument for the free outdoor check first.
What this looks like
From the outside, this usually shows up as the inducer spins up but the burners never fire — that walkthrough covers what to check in order, and when it stops being a homeowner job.