How Long Should My Diesel Heater Exhaust Be?

This is a common question, and the short answer is simple:

The rule of thumb is: the shorter the better.

There is no performance benefit in running the exhaust all the way to the edge of the van or beyond. The sole purpose of the diesel heater exhaust is to safely and efficiently expel combustion gases (including CO) — and this is best achieved with minimal exhaust length.

Why Shorter Is Better

A shorter exhaust:

• Allows gases to exit more efficiently
• Reduces back pressure
• Places less strain on the heater’s combustion fan and motor
• Improves overall heater reliability and longevity

Longer exhaust runs do nothing to improve safety or performance and can actually increase wear on the heater over time.

What About Exhaust Gases Re-Entering the Van?

Once expelled, exhaust gases disperse rapidly into the outside air. They do not “hang around” or travel back into the van — especially when the vehicle is stationary.

It’s also worth pointing out that when a diesel heater is in use, windows and doors are typically closed, which makes the concern about exhaust gases filtering back inside even less likely.

Peace of Mind Options

If you still have any concerns, the solution is simple:

We can supply and install a CO (carbon monoxide) alarm for added peace of mind. They’re inexpensive, effective, and a smart addition to any caravan or camper setup.