Posts

All the articles I've posted.

• Navien E110 Error Code - Causes & Fix

  30 May, 2026

  E110 means abnormal air pressure or blocked airflow. Most common fix: clean the internal air filter and check vents for blockages.

• Navien E009 Error Code - Causes & Fix

  30 May, 2026

  E009 means abnormal fan motor speed on your Navien tankless. Most often caused by blocked intake, dirty filter, or failed blower motor.

• Navien Alarm 438 - Causes & Fix

  30 May, 2026

  Alarm 438 means a recirculation system fault. Most often a closed valve, clogged filter, or failed circulation pump stops flow in the loop.

• Noritz F76 Error Code - Causes & Fix

  30 May, 2026

  F76 means communication lost between paired Noritz units. Most likely fix: power down, reseat the quick-connect cord, and restart.

• Navien Alarm 415 - Causes & Fix

  30 May, 2026

  Alarm 415 means the flow sensor isn't detecting water movement. Most often caused by debris or scale in the sensor. Clear the inlet filter first.

• Navien E515 Error Code - Causes & Fix

  30 May, 2026

  E515 signals an abnormal PCB condition on your Navien tankless. Most common fix is reseating connectors or replacing the main control board.

• Navien E038 Error Code - Causes & Fix

  30 May, 2026

  E038 means the flow sensor isn't spinning. Open and close the pressure relief valve to free debris, or replace the sensor if stuck.

• Navien E029 Error Code - Causes & Fix

  30 May, 2026

  E029 means air pressure sensor abnormality. Most common fix: check wiring, clear vent blockages, or replace the air pressure sensor.

• Navien E021 Error Code - Causes & Fix

  30 May, 2026

  E021 means the cold water inlet thermistor has an open circuit. Most common fix: replace the failed sensor or repair its wiring.

• Navien E027 Error Code - Causes & Fix

  30 May, 2026

  E027 means abnormal air pressure sensor activity. Most often caused by blocked venting or a dirty air filter. Check airflow first.

• Navien E016 Error Code - Causes & Fix

  30 May, 2026

  E016 means heat exchanger overheat protection. Most common fix: clean the inlet filter and check for scale buildup in the exchanger.

• Navien Tankless E013 Error Code - Causes & Fix

  30 May, 2026

  E013 on Navien tankless means abnormal pump operation. Most common fix: check pump wiring and connectors, then replace the pump if faulty.

• Navien E011 Error Code - Causes & Fix

  30 May, 2026

  E011 on Navien tankless means high water pressure or a faulty pressure sensor. Most often fixed by replacing the water pressure sensor.

• Navien E010 Error Code - Causes & Fix

  30 May, 2026

  E010 signals abnormal air pressure or airflow fault in the combustion system. Clean the air filter and check vents for blockages first.

• Navien E008 Error Code - Causes & Fix

  30 May, 2026

  E008 means the outlet thermistor circuit is shorted. The most common fix is replacing the outlet temperature sensor or its wiring.

• Navien E007 Error Code - Causes & Fix

  30 May, 2026

  E007 means the hot water outlet thermistor circuit is open. Most likely fix: replace the outlet temperature sensor or repair its wiring.

• Navien E006 Error Code - Causes & Fix

  30 May, 2026

  E006 means the heating supply outlet thermistor is shorted. Most units need a new thermistor after checking wiring and connectors.

• Navien E005 Error Code - Causes & Fix

  30 May, 2026

  E005 means the flow sensor isn't spinning properly. Most likely fix: clear debris from the sensor or replace the flow sensor assembly.

• Navien E004 Error Code - Causes & Fix

  30 May, 2026

  E004 means false flame detection. Check for vent blockages and clean the flame rod first-most common fix for this safety lockout.

• Navien E002 Error Code - Causes & Fix

  30 May, 2026

  E002 means low water pressure or insufficient supply to your Navien tankless heater. Check that the inlet valve is fully open first.

• Lennox Furnace E275 Error Code - Causes & Fix

  30 May, 2026

  E275 means flame sensed out of sequence. The furnace detected flame when it shouldn't have, then lost it. Check for a leaking gas valve.

• Lennox E204 Error Code - Causes & Fix

  30 May, 2026

  E204 means blower motor communication fault. Most often fixed by repairing damaged wiring harness or replacing the blower motor.

• Navien E001 Error Code - Causes & Fix

  30 May, 2026

  E001 on Navien tankless heaters usually signals a flame detection or ignition fault. Clean the flame rod and check gas supply first.

• Lennox E290 Error Code - Causes & Fix

  30 May, 2026

  E290 means ignitor circuit fault on your Lennox furnace. The hot-surface ignitor has failed or its wiring is open. Replace the ignitor.