hi this is Sarah from The Savvy professor and in today's video we'll discuss how to fix the BOS tankless water heater error code EC but first what does error code EC mean the EC air code indicates a failed ionization problem the following are the common causes of the air code a dirty flame sensor the incorrect gas type or a blocked exhaust pipe now let's look at the best solutions to fix the air clean out the flame sensor turn off the power and gas supply to the heater remove the covering panel to access the flame sensor gently clean out any dirt or debris buildup on the flame sensor with a soft brush reassemble the heater and test it check the gas type of the water heater determine the recommended gas type from the label on the water heater cover confirm you're using the correct gas type for your heater if it's not the right type disconnect it and purchase the correct gas type inspect the exhaust pipe unplug the heater from the power source and locate the exhaust pipe on your heater disconnect the exhaust pipe from the heater and inspect the exhaust pipe for damage and obstruction remove any foreign object obstructing the exhaust pipe and reassemble the exhaust pipe and test the heater if the machine is still not working contact a professional for further guidance and that's it thanks for watching till next time