Navien tankless error code 110 01 indicates an exhaust temperature or air intake restriction issue typically caused by blocked venting.
Table of Contents
- What does error code 110 01 mean on a Navien tankless water heater?
- Why does my Navien water heater trigger error code 110 01?
- How can I safely clear error code 110 01 on my Navien unit?
- What should I do if the Navien 110 01 error code returns?
- Quick reference table for Navien airflow symptoms
- When should you stop troubleshooting and call a professional?
- What information should you have ready before calling for service?
- How can you keep error code 110 01 from coming back?
What does error code 110 01 mean on a Navien tankless water heater?
Error code 110 01 indicates an exhaust temperature abnormality or blockage in the venting system, restricting proper airflow.
When your Navien tankless water heater detects abnormal exhaust conditions, it triggers error code 110 01 to prevent dangerous carbon monoxide buildup and internal overheating. This safety lockout halts unit operation immediately until the restriction is cleared.
- The unit shuts down burners to prevent hazardous exhaust gas leaks.
- It specifically points to blocked, damaged, or improperly installed venting pipes.
- Blockages can stem from outdoor debris, leaves, or bird nests inside the terminal.
- Internal heat exchangers may also show soot buildup if combustion is incomplete.
- Always confirm your specific model manual for exact error definitions.
Why does my Navien water heater trigger error code 110 01?
Common causes include blocked outdoor exhaust vents, pinched intake pipes, or accumulated soot inside the combustion chamber.
Over time, environmental factors and lack of maintenance frequently compromise the delicate balance of airflow required by high-efficiency tankless units. Identifying the root cause ensures you fix the actual restriction rather than just resetting the appliance.
- Leaves, snow, or animal nests obstructing the outdoor concentric vent terminal.
- Excessive condensation freezing inside the exhaust piping during freezing weather.
- Intake or exhaust pipes disconnected or cracked inside the wall or ceiling.
- Incorrect vent length or too many elbows exceeding manufacturer specifications.
- Dirty burner components causing improper combustion and high exhaust temperatures.
How can I safely clear error code 110 01 on my Navien unit?
Perform a power reset, inspect the outdoor vent termination, and clear any visible obstructions safely.
Before performing any physical checks, always turn off the power at the dedicated circuit breaker to protect yourself from electrical shock. Never attempt to disassemble gas-carrying components or sealed venting joints yourself.
- Turn off the power switch on the water heater and the main circuit breaker.
- Locate the outdoor exhaust and intake vent terminals on your exterior wall or roof.
- Remove any visible leaves, debris, cobwebs, or ice blocking the vent openings.
- Check that all indoor visible PVC or stainless steel vent pipes remain securely connected.
- Wait 60 seconds, restore power at the circuit breaker, and test hot water operation.
What should I do if the Navien 110 01 error code returns?
Inspect internal venting connections, check for condensate line blockages, and prepare for professional service.
If a simple reset and exterior vent clearing do not resolve the issue, the restriction likely resides deep within the internal venting or combustion system. Continuing to force resets can lead to permanent component damage or safety lockouts.
- Ensure the condensate trap is completely clear and draining freely into a floor drain.
- Verify that the intake air filter inside the unit is clean and free of dust.
- Inspect the interior exhaust piping joints for signs of exhaust gas leakage or discoloration.
- Power down the system completely if you smell any unusual odors or gas.
- Contact a licensed plumbing professional to inspect the internal heat exchanger and flue.
Quick reference table for Navien airflow symptoms
Match your specific operational symptom to the likely cause and recommended immediate fix.
Navien tankless water heaters display various error codes related to combustion and airflow. Use this quick reference table to differentiate similar venting and sensor errors.
| Symptom | Likely cause / fix |
|---|---|
| Error 110 01 on display | Exhaust blockage; clear outdoor vent. |
| Error E003 or 100 | Low fan speed; inspect blower motor. |
| Error 390 | Neutral wire issue; check electrical ground. |
| Unit clicks but fails to ignite | Gas supply closed; check gas valve. |
When should you stop troubleshooting and call a professional?
Stop immediately and call a licensed technician if you detect gas odors, damaged venting, or internal electrical issues.
Gas appliances demand strict adherence to safety protocols to prevent carbon monoxide poisoning or explosion risks. Professional technicians carry specialized combustion analyzers and diagnostic tools required for safe internal repairs.
- Stop immediately if you smell natural gas or propane near the appliance.
- Call a professional if exhaust piping is cracked, separated, or leaking inside walls.
- Never attempt to service gas valves, burner assemblies, or electronic control boards.
- Contact a licensed plumber if error code 110 01 persists after clearing exterior vents.
- Ensure the technician is certified to work on tankless gas water heaters.
What information should you have ready before calling for service?
Gather your exact model number, serial number, warranty status, and a list of troubleshooting steps already attempted.
Having accurate appliance details ready speeds up dispatch times and helps support representatives send the right technician with correct replacement parts. Look for the rating plate sticker located on the side panel of your Navien unit.
- Locate and write down the complete model and serial number from the side label.
- Check your purchase date and warranty registration status to see if parts are covered.
- Note the exact error code sequence currently displayed on the front panel.
- Write down every troubleshooting step you already performed, like power resets.
- Describe whether the error occurs immediately upon startup or during heavy water usage.
How can you keep error code 110 01 from coming back?
Schedule annual preventative maintenance, inspect outdoor vents seasonally, and keep air intake filters clean.
Proactive maintenance is the best defense against recurring airflow restrictions and unexpected hot water outages. Regular homeowner checks combined with professional servicing keep your tankless unit running efficiently for years.
- Inspect outdoor exhaust and intake vent terminals at least four times a year.
- Clean the internal air intake filter every six months to prevent dust buildup.
- Flush the heat exchanger annually to remove scale and mineral deposits.
- Keep landscaping, bushes, and outdoor furniture away from exterior vent terminations.
- Schedule a professional tune-up with a certified technician before every winter.
Frequently Asked Questions
Can I use my Navien water heater while error code 110 01 is showing?
No, the unit enters a mandatory safety lockout to prevent hazardous exhaust leaks or overheating. You must resolve the airflow restriction and clear the error before hot water production resumes.
What tools do I need to check the outdoor vent termination?
You typically only need a flashlight and heavy gloves to clear exterior leaves, debris, or cobwebs. Never insert rigid tools inside the pipe that could crack the plastic PVC or stainless steel venting.
Does cold winter weather cause error code 110 01?
Yes, freezing temperatures can cause heavy condensation buildup or icicles to form around the outdoor exhaust terminal. This restricts airflow and triggers the 110 01 safety lockout until thawed and cleared.
How do I reset my Navien tankless water heater after clearing a blockage?
Turn off the power switch on the front panel or flip the dedicated circuit breaker off for 60 seconds. Turn the power back on, and the unit will attempt a fresh ignition cycle.
Is Navien error code 110 01 covered under warranty?
Component parts are typically covered under the manufacturer warranty, but labor costs depend on your installer agreement. Review your owner manual or contact manufacturer support to verify specific warranty terms.
Bottom Line
Turn off the power breaker and inspect your outdoor vent terminal for blockages first. Addressing exterior airflow restrictions safely resolves most Navien 110 01 error occurrences.
Sources
- Navien Owner’s Manual
- Navien Installation Manual
- Manufacturer Support Page