E193 Moderate Easy DIY

Navien Tankless Water Heater E193 — Condensate Drain Blockage

Navien Tankless Water Heater · Error code E193

What E193 Means

The condensate trap or drain line is blocked, allowing condensate to back up inside the unit.

Symptoms

  • E193 on display
  • Water under or inside the unit
  • Unit shuts down
  • Gurgling sound

Common Causes

1
Plugged condensate trap

Sediment and combustion byproducts clog the trap over time.

2
Kinked or frozen condensate hose

Drain line pinched or frozen in unconditioned space.

3
Plugged neutralizer

Spent media or debris blocking the condensate neutralizer outlet.

How to Fix It

  1. Power off the unit.
  2. Remove and flush the condensate trap with warm water.
  3. Inspect the drain line for kinks, sags, or freezing; reroute as needed.
  4. Service or replace condensate neutralizer media if installed.
  5. Verify free flow from trap to drain before restoring power.

Parts You May Need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

Common replacement Condensate neutralizer media View on Amazon→

More Navien Tankless Water Heater Codes

E003 E003 — Ignition Failure E003C E003C — Cascade Ignition Failure E012 E012 — False Flame / Flame Loss E016 E016 — Overheat / High-Limit Trip E027 E027 — Gas Type Setting Error E030 E030 — Fan / Combustion Blower Fault

All Navien codes → All tankless water heater codes →

Verified against manufacturer documentation: navieninc.com

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.