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Navien Error Code E353: Water pressure sensor fault (Combi Boiler)

Updated · by Aurora Star Tech Inc.

Navien error code E353 on a combi boiler means: Water pressure sensor fault. It is also called Navien diagnostic code E353.

Medium severityCombi BoilerNavien NCB-H · Navien NFC-H

Homeowner? What Navien code E353 means for you

Check, then call Your combi boiler is reporting: Water pressure sensor fault. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.

Safe things you can check yourself

  • Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
  • Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
  • Look at the pressure gauge on the boiler. If it reads much lower than usual or near zero, or water is leaking, call a technician.
  • Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
  • Check that the boiler gas valve is open (handle in line with the pipe).
  • Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.
  • If only hot water is missing, check that the hot water tap is open far enough to start the heater.

Call (647) 657-2977Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Navien error code E353 mean?

The water pressure sensor reading is abnormal. NFC-H manual lists the reset type as: Auto reset.

Applies to: Navien fire-tube combi boilers, NFC-H series (NFC-250/200H, NFC-250/175H) and NCB-H combi boilers (NCB-250/150H, NCB-240/130H, NCB-240/110H, NCB-190/080H, NCB-190/060H)

Common causes of Navien code E353

  • Sensor wiring
  • Failed pressure sensor
Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Navien models that use code E353

NCB-190/060HNCB-190/080HNCB-240/110HNCB-240/130HNCB-250/150HNFC-250/175HNFC-250/200H

Other Navien Combi Boiler codes

CodeMeaning
E218Heating return temperature sensor fault
E278External (system) supply sensor not detected
E279External (system) return sensor not detected
E302Low water pressure (internal LWCO)
E351Auto feeder (make-up water) valve fault
E352High water pressure
E407DHW outlet temperature sensor fault
E421DHW cold water inlet sensor fault
E434Water adjustment (flow control) valve fault
E439No DHW flow detected / flow sensor fault
E441DHW outlet 2 sensor fault
E445Mixing (bypass) valve fault

All Navien Combi Boiler error codes →

Navien code E353: homeowner questions

What does Navien code E353 mean?

Water pressure sensor fault. The water pressure sensor reading is abnormal. NFC-H manual lists the reset type as: Auto reset.

Is it safe to keep using my combi boiler with code E353?

It depends on the cause. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.

Can I reset Navien code E353 myself?

You can try one reset (power off for 30 seconds, then on). If Navien code E353 comes back, the cause is still there and a licensed technician should check it.

Who can fix Navien code E353 near me?

Aurora Star Tech Inc. repairs Navien combi boilers in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: Tankless Water Heater No Hot Water: What to Check · Boiler Not Heating: What to Check

Troubleshooting guides

Source: Navien NCB-H Installation & Operation Manual, 11.7 Understanding Error Codes, p.129-130; Navien NFC-H Installation Manual, 11.7 Understanding Error Codes, p.127-128. Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

Emergency HVAC Service

647-657-2977