Girard Tankless Water Heater Error Codes
This is a complete guide on Girard Tankless Water Heater Error Codes. In this article, I will describe the meaning, what causes the error code to pop up, and how you can reset the error code shown on the UCP (User Control Panel). So, keep reading.
11 Common Girard Tankless Water Heater Error Codes
If you are in rush, check the following table to learn each error meaning, their reasons, and solutions in a quick view:
| Error Code | Meaning | Cause | Solution |
| E0 | Water outlet temperature probe fault | Defective wire connection, faulty probe, open circuit | Check resistance with multimeter, check wire connection, replace probe |
| E1 | Ignition failure | Lack of gas, low inlet pressure, faulty igniter/connections, improper distance between igniter and burner, dirt/obstruction, lost integrity of wires | Check this guide to learn how to reset the E1 code |
| E2 | Flame sensing interrupted | Same causes as E1 | Follow steps in E1 troubleshooting guide |
| E3 | ECO thermostat has opened. | Insufficient water pressure, thermostat too high, defective ECO, control board failure | See reset guide here |
| E4 | Water inlet temperature probe fault | Internal failure, loose connection | Replace probe, check and tighten connection |
| E5 | Blower motor fault | Faulty motor wire, defective motor, bad control board, loose CN1 plug, debris in blower | See diagnosis guide here |
| E6 | Over temperature | Improper water flow | Ensure proper water flow |
| E7 | Linear valve failure | Bad connection at wires | Check connections, measure resistance, replace valve |
| E8 | Air pressure switch failure | Defective motor, blockage in air supply/exhaust | See reset guide |
| E9 | Flame sensed before ignition | Short in flame sensor | Replace igniter assembly |
| EN | Ran longer than 20 minutes | Normal operation | Do soft reset |
1. Error Code E0
The E0 code on the Girard Tankless Water Heater means the water outlet temperature probe is at fault. It occurs when the control board senses the flow sensor is on while the output thermistor or water outlet temperature is open.
Apart from this, a defective wire connection of the outlet temperature probe is responsible for the error code E0.
Nonetheless, an internal failure in the temperature probe can cause the water heater to pop up this error message on the UCP.
How To Fix:
First, get a multimeter and check the resistance of the outlet temperature probe is not an open circuit or a short.
Second, check the wire connection of the outlet temperature probe and verify that the wire connection is good.
Finally, go forward to replace the outlet temperature probe or hot water thermistor if the error code persists. You can read the following guide to learn how to replace the outlet water temperature probe or output thermistor:
2. Error Code E1
Ignition failure or accidental flame off during ignition is what the E1 code stands for on Girard Tankless Water Heater. The tankless unit will pop up on the display due to one of the following reasons:
- Lack of Gas in the tank
- Low inlet gas pressure
- Faulty igniter
- Faulty igniter connections
- Improper distance between the igniter and the burner
- Accumulated dirt or obstruction between the igniter and the burner
- The integrity of brown and black wires on the 8-pin connector gets lost
To reset this error code, read this guide: Girard Tankless Water Heater Error Code E1. In this article, I broke down everything you need to know to erase the E1 fault code.
3. Error Code E2
The E2 code on the Girard Tankless Water Heater indicates that the flame sensing gets interrupted during normal operation. All the reasons for the error code E1 are also responsible for this fault code.
In other words, you can reset the E2 code by following each troubleshooting step mentioned in this article: Girard Tankless Water Heater Error Code E1.
4. Error Code E3
When the water at the outlet is above 140°F during normal operation, the unit will trip the ECO sensor and give an E3 code on the UCP. It occurs due to one of the following reasons:
- Insufficient water pressure
- Set the thermostat too high
- Defective ECO
- Control board failure
- Excessive Hot Condition
Fortunately, I published a detailed guideline on Girard Tankless Water Heater Error Code E3 that will show you how to reset the code. Read that article and have the E3 code reset.
5. Error Code E4
Girard Tankless Water Heater Error Code E4 indicates that the water inlet temperature probe is at fault. Generally, the inlet temperature probe or input thermistor will be defective due to internal failure or loose wire connection.
How To Fix:
If the input thermistor is at fault, you should replace it. Read this guide to learn how to replace the thermistor on a Girard Tankless Water Heater. Next, check the input thermistor wire connection and tighten it if required.
6. Error Code E5
The E5 error code indicates that the blower motor is at fault. Typically, a faulty wire in the motor or defective blower motor is responsible for this diagnostic code.
Apart from these, a bad control board, loose CN1 wire plug, and debris in the blower assembly are also liable for the E5 code. To learn the diagnosis of this error code, read this guide: Girard Tankless Water Heater Error Code E5.
7. Error Code E6
Over temperature is what the error code E6 indicates on the Girard Tankless Water Heater. When the outlet temperature has exceeded 140°F for 3 seconds, this unit will give the E6 code.
The main reason behind overheating is purging all of the air out of the plumbing and high-temperature cold water coming into the unit. If you live in Southern states, you will experience this issue.
To avoid this issue, ensure that the water flow is proper.
8. Error Code E7
Girard Tankless Water Heater Error Code E7 means Linear Valve failure. When this code appears on the UCP, the control board fails to sense the linear valve.
I recommend you check the connection of the white and red wires on the 8-wire plug and the connections behind the firewall. You can measure the resistance of the coil of the linear valve at the white and red wires of the 8-wire connector.
The resistance should be approximately 85 ohms. If not, you should replace the gas valve.
9. Error Code E8
Error code E8 means air pressure switch failure. In other words, the control board fails to detect the air pressure switch for 7 seconds before ignition, or the switch is cut off for 2 seconds during normal operation.
The E8 code could be due to a defective motor or a blockage in the air supply or the exhaust system. To learn how to reset the error code, read this article: Girard Tankless Water Heater Error Code E8.
10. Error Code E9
Error code E9 indicates that the flame is sensed before ignition. The control board will throw this error code if it detects a short in the flame sensor. To resolve this issue, you should replace the entire igniter assembly.
11. Error Code EN
EN code on Girard Tankless Water Heater indicates that the water heater ran longer than 20 minutes.
Generally, the control board turns off the burner and shows the ‘EN’ code on the UCP after 20 minutes of operation.
A soft reset will help you erase this error code. Regarding this, turn off the hot water faucet and turn it back on.
End-Note
I depicted each error code’s meaning, the reasons, and how you can reset the fault code in this article: Girard Tankless Water Heater Error Codes. Now, follow the resetting procedure I mentioned for each error code and fix the issue. However, if you fail to reset a certain error code, contact the Girard Tankless Water Heater Customer Service.
Read Further:
Sohel Rana is an expert writer on plumbing, HVAC, and appliance repair & troubleshooting. Since 2020, he has written on these specific topics, though his writing journey began in 2018. To learn more about him, read About Us page.
