Error Code 32
High

Bryant 355MAV Error Code 32: Low-Heat Pressure Switch Did Not Close or Reopened

TL;DR
Your Bryant 355MAV's low-heat pressure switch failed to close or reopened, most commonly due to a plugged condensate drain. Clear the drain and check vent pipes for blockages.
Disclaimer
This article is for informational purposes only and does not guarantee the accuracy or completeness of the information provided. Always turn off power and gas supply before attempting any repairs. If you smell gas, leave immediately and call your gas company. Consult a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk.

What Does Code 32 Mean?

Status code 32 on the Bryant 355MAV indicates that the low-heat pressure switch input failed to close on a call for low-heat, or opened during low-heat operation. If the switch opens during the blower on-delay period, the blower will run for the selected off-delay. If it opens within 5 minutes after ignition, the next heating cycle will be restricted to high-heat only.

The low-heat pressure switch monitors the draft created by the inducer motor at low speed. Since the Bryant 355MAV is a two-stage furnace, it has separate pressure switches for low-heat and high-heat operation. The low-heat switch requires less draft pressure, so it is more sensitive to partial blockages that might not affect high-heat operation.

The most common cause is a plugged condensate drain. This is a condensing furnace that produces water during operation, and if the drain becomes clogged, water backs up into the inducer housing and reduces the draft. Improper vent sizing, restricted combustion air supply, or a failed pressure switch are other possible causes.

Common Causes

Cause Likelihood DIY?
Plugged condensate drain Most common ✗ Call a pro →
Improper vent sizing or restricted combustion air supply Common ✗ Call a pro →
Failed or out-of-calibration pressure switch Uncommon ✗ Call a pro →

When to Call a Professional

Contact a licensed HVAC technician if:

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Sources

  1. Bryant 355MAV Series I Installation, Start-up, and Operating Instructions

✓ Verified against manufacturer service manual — March 2026