Navien Tankless flashing an error code?
If you’re looking for help fixing your Navien tankless water heater or combination boiler, look no further than to the experts the manufacturer refers to Natural Choice Heating & Cooling as Navien PRO’s. We have been installing tankless since 2005 and have well over 3,000 clients enjoying endless hot water!
It is ‘always’ best practice to have a licensed Gas technician complete a thorough assessment, however it is good to know what you are looking at for the reason you have “no hot water”.
If you have a tankless water heater, you’ve made a wise investment that will deliver endless hot water for 20+ years. Tankless water heaters need far less in the way of maintenance and servicing than traditional tank water heaters, but they still do need to be maintained, and when they have problems, it’s important to know what to do. We service all brands, but for this post we’re focusing on Navien tankless water heater troubleshooting because the self diagnostics tool provides codes that makes it easier to diagnose and address issues.
We’re huge fans of Navien tankless systems! Your Navien tankless water heater is a smart water heater, meaning it is equipped with a self-diagnostic tool that continuously monitors if the unit is functioning properly. When something goes wrong, the unit displays an error code. Using this Navien tankless water heater error code guide, you can quickly determine what the problem is and if you need a plumber to service the unit or if you can fix it yourself.
Tankless Error Code Breakdown
Problem: No Water comes out when the hot water tap is opened
Possible Cause:
- Is the cold water inlet filter clean?
- Is an Error Code displayed on the front of the panel?
- Is the tankless frozen (was there a lengthly power outage?)
What to do (most suggestions are best completed by a trained license technician) Ensure Main water supply is on
- Ensure Supply & Outlet (not the service valves) valves are open
- When was it serviced last, the strainer might be clogged/needs cleaning (Tankless flushing)
Problem: Water from the hot water faucet is cold or turns cold & stays cold
Possible Cause:
- Is the hot water faucet opened wide enough?
- Is there an Error displayed on the display panel?
What to do (most suggestions are best completed by a trained license technician)
- Open the faucet to full as the tankless systems require a minimum of 0.5 Gallons per minute flow in order for the tankless unit to start producing hot water
- Check below what the error code is referring to
Problem: Water is not HOT enough
Possible Cause:
- Is the temperature set too low
- Have you waited long enough?
What to do
- Maximum temperature suggestion is 120F, anything higher could cause skin burn or worse
- Setting the temperature higher than 120F can not only sculled you, it can add longer wait times to receiving hot water depending on how cold ground water is
- Winter with very cold ground water will increase delayed time regardless of temperature chosen
Problem: Water is TOO HOT
Possible Cause:
- Is the temperature set too high?
What to do
- Maximum temperature suggestion is 120F, anything higher could cause skin burn or sculled
- Setting the temperature higher than 120F can not only sculled you, it can add longer wait times to receiving hot water depending on how cold ground water is
- Winter with very cold ground water will increase delayed time regardless of temperature chosen
Error Code E003: Ignition Failure
Fix – Call a Licensed Gas Fitter/Company. What has happened is the unit has a part failure.
Error Code E004: False Flame Detection
Ensure that the electrical cord is properly grounded plugged in
Error Code E012: Flame Loss
- Is there anything blocking the intake/exhaust outside your home?
- Was your gas meter supply turned off (do not adjust, either call Gas supply company or Us)
- Is the gas valve to the tankless off or half closed?
Error Code E016: Overheating of Heat Exchanger
- Is the main water supply valve to the tankless system partially closed?
- System might have a clog in the strainer built into the tankless reducing water flow
- System likely needs maintenance/flushing
Error Code E030: Abnormal Exhaust Temperature
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E046: Abnormal Operation: Limit Control
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E047: Abnormal Operation : Exhaust Thermostat
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E060: Abnormal Operation: Dual Venturi
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E109: Abnormal Operation: Fan Motor
- Is the intake blocked outside?
- Clean the intake filter (might want to have a trained technician complete this task)
- Fan motor might need replacing
Error Code E110: Abnormal Air Pressure
- Ensure the exhaust is free of obstructions
- Clean the intake filter (might want to have a trained technician complete this task)
Error Code E205: Heating Supply Thermistor Open or Short Circuit
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E218: Heating Return Thermistor Open or Short Circuit
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E351: Abnormal Auto Feeder valve – Make up water
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E352: High Water Pressure
- Are you on well water and the pump set too high?
- You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E353: Abnormal Operation: Water Pressure Sensor
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E407: Hot Water Outlet Thermistor Open or Short Circuit
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E421: Cold Water Outlet Thermistor Open or Short Circuit
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E439: Abnormal Operation: Flow Sensor
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E515: Abnormal Operation: PCB
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E517: Abnormal Operation: DIP Switch Setting Incorrect
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E594: Abnormal Operation: EEPROM
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E615: Abnormal Operation: Input and Memory
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E736: Cascade Communication
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E740: Abnormal Operation: Outdoor Temperature Sensor (most systems only have this in combination units)
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E777: Abnormal Operation: LWCO
You will need to call a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Error Code E782: Abnormal Operation: Main Panel Communication
Call Navien tech support 1-800-519-8794 or call Us a licensed HVAC to handle this. This error code should only be checked by a licensed technician.
Need a Gas fitter for Tankless Water Heater Help?
This post is about Rinnai tankless water heater troubleshooting because that’s the brand we install the most often, but we have deep experience with all brands of tankless (on demand) water heaters. Give us a call at 905.424.2090 to service your tankless water heater. We look forward to working with you!
Tasks to Leave to a Tankless Repair Expert
When troubleshooting your tankless doesn’t solve your hot water issues, never hesitate to contact a trained HVAC contractor. Any tankless, regardless of its age, may pose combustion- or gas-related safety hazards, so it’s always a good idea to have an expert examine the unit and suggest the best course of action.
