Headlamp condensation build-up

The consumer’s issue:

“I purchased a used nine-month-old ‘68-plate hatchback in July 2019. Around three months after buying the car, I noticed that condensation had built up on the inside of the headlight unit on the driver’s side. I contacted the dealership where I bought the vehicle, and they advised me to run the engine for an hour with the headlights on to see if this solved the problem. However, it didn’t, so I took the car to the business to be inspected, and they agreed that there was a significant level of condensation within the headlight.   


The business agreed that the part should be replaced, but they found a memo from the manufacturer explaining that this issue was not covered by their new car warranty. Therefore, they wouldn’t change the unit at their expense. I then contacted the manufacturer directly after being advised to do so by the dealership, and they said that there would be a three-day investigation, and that this issue was not covered under the terms of the warranty.


I have spent £12,000 on this vehicle, and have only had it for three months. I can put up with a little bit of condensation, but this is far worse than that, and the dealership has agreed with the extent of the issue. I therefore feel that the manufacturer should replace the headlamp with a new one at no cost to myself.”  

The accredited business’ response:

  • Having reviewed our case file, we can confirm that the consumer reported bad condensation in one of their vehicle’s front headlamps. The car had already been inspected by our authorised retailer.
  • We spoke to the dealership about the inspection they carried out, and they stated that they had followed our instructions before reaching their conclusion that no manufacturing defect or material defect was present.
  • We set out a comprehensive series of checks, which must be carried out in the event of such a complaint. These include looking at the caps and seals on the headlamps, and testing of the lens.
  • The time pattern for the dissipation process for condensation is extremely dependent on the temperature in the immediate area and the relative humidity of the air.
  • Because of the open ventilation system, which is however, protected from spray, and which is needed for pressure compensation, different “climate zones” occur within the headlamp, thereby resulting in fogging of the lens. For example, warm areas occur within the headlamp with relatively cooler areas on the other side. The heating is generated by the heat emitted by the light source, whilst the cooling of the lens is primarily caused by the slipstream.
  • Because of the complex design of the ventilation openings, expanding heated dry air is forced out of the headlamp. After switching off the light source, the air in the headlamp cools down slowly. This causes air saturated with moisture to be drawn from the outside into the inside of the headlamp. This situation can cause condensation to occur on the inside of the lens.
  • The process involved in condensation in the headlamp is caused by physics and does not affect the function of the headlamp in any way.
  • We are therefore unable to uphold the customer’s complaint and change the headlamp at no cost to the customer, as no technical defect under the terms of the warranty was identified.

The adjudication outcome:

  • The Motor Ombudsman adjudicator reviewed the evidence, which did not demonstrate a mistake in the workmanship or parts used in the manufacturing process.
  • Whilst it was accepted that the headlamp did suffer from condensation, as evidenced by the photographs the consumer provided, this did not show that a manufacturing defect existed, such as a crack in the materials which was causing excessive condensation.
  • The inspection followed the manufacturer’s guidelines, and the dealership was unable to find a fault with the vehicle.
  • In addition, the consumer did not provide any further evidence, which contradicted the business’ findings, such as a technical report or comments from a technician.
  • Therefore, the adjudicator did not find that the business had breached the New Car Code of Practice, and the complaint could not be upheld in the consumer’s favour. No further recommendations were made.


  • Neither party responded to the decision, and therefore it was assumed that both parties accepted the outcome. The case was then closed.