E4 error code on a pellet heater has to do with the temperature sensors. Pellet heaters usually have at least two sensors that monitor the temperature of the fire. The first is a proof of fire sensor. This sensor detects that a fire has started during ignition and is burning and enables the pellet heater to switch from ignition to heating mode. The second sensor, sometimes called a high limit sensor, detects if the pellet heater is getting too hot. If either of these sensors is faulty you will get an E4 error code on your pellet heater. Read the are pellet heaters reliable post if you’d like to know what other parts may need replacing.
What to Do if you Experience E4 Error Code
Let the heater shut down if it hasn’t and then clear the error code. Press the thumbs up button to clear the error code. If that fails power the pellet heater on and off. Switch it off at the power point, wait 10 seconds and then switch it back on. This should clear the error code and you will be able to start your pellet heater again. However, be careful because an E4 error code indicates a problem with a temperature sensor on your pellet heater. The pellet heater is not safe to use until the problem that caused the error has been fixed.
Proof of Fire Temperature Sensor
Check the wires to the proof of fire temperature sensor. This sensor is usually located on the exhaust fan housing, so you will have to remove the side panels from your pellet heater to gain access. Many pellet heaters include a backup temperature sensor by default. If the wires are connected and not loose and your pellet heater comes with a backup temperature sensor then remove the wires and connect the backup sensor. Try starting your pellet heater again to see if the E4 error code is triggered. If your pellet heater does not have a backup sensor and the wires were connected properly, you will most likely need to replace the sensor.
High Limit Temperature Sensor
The high temperature sensor protects the pellet heater from over heating. Where it is located on your pellet heater will depend on the model. For some models this is on the back of the burn box. Again, check the wires are connected properly. It’s unlikely you will have a backup sensor like the proof of fire switch. If the wires look fine then you will most likely need to replace the sensor. Contact your retailer and arrange a service call if you are unable to replace the sensor yourself.
Bypassing Temperature Sensors
This should ONLY be done for testing purposes and only by experienced pellet heater owners. Temperature sensors can be bypassed, and this can be useful if you have replaced the sensors but still getting the error and want to try and troubleshoot in detail where the cause of the E4 error code is. To bypass a temperature sensor, remove the two wires from the sensor and connect them together. Once these two wires have been connected it effectively bypasses the temperature sensor. This should allow you to troubleshoot and find out what is going on. Again, ONLY do this for testing and if you are an experienced pellet heater owner.
E4 Error Code Summary
The E4 error code is triggered by a faulty temperature sensor. This could be the proof of fire sensor that is used during startup or the high limit sensor that protects your pellet heater from over heating. In most cases you will need to replace these sensors but it doesn’t hurt to make sure the wires are connected properly. You can bypass the temperature sensors by unplugging the sensor and connecting the two wires with a paperclip. However, only do this for testing purposes.
The PFTas pellet heater manual will provide some brief and basic information about Error codes