What does the Vaillant ecoTEC plus F38 fault code mean?
The F38 fault code indicates a problem with the combustion air switch, which is responsible for ensuring that the boiler receives the correct amount of air for combustion. This issue can prevent the boiler from operating safely and efficiently.
Common Causes
- Blocked Air Intake: Debris or obstructions in the air intake can prevent proper airflow, leading to the fault.
- Faulty Air Pressure Switch: The air pressure switch itself may be malfunctioning, failing to detect the correct air pressure levels.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for any issues related to gas or electrical components, including the combustion air switch. Attempting to fix it yourself could pose safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for a faulty combustion air switch on a Vaillant ecoTEC plus is around £150 to £250, depending on parts and labour. This includes the cost of the replacement switch and the engineer’s service fee.