Smoke Problem with Espar, Webasto and Other Heaters

Excessive smoking of Espar and Webasto heaters - cause and remedy

This article describes usual causes and remedies to excessive (startup) smoking/fumes of Espar, Webasto and other similar types of fuel-fired heaters.


Cause of Smoke and Remedy


Symptoms Cause and Remedy
Heater smokes heavily during startup (first 5-10 minutes of operation), then fumes gradually reduce as heater warms up Heater requires maintenace. Smoke is caused by soot deposits on interior walls of combustion chamber, that needs to be removed. To complete this you will need a maintenance kit. Some of our kits are compatible with Espar and Webasto.
Heater smokes heavily throughout the entire heat cycle 1. Combustion airways obstructed, damaged or filled with water.
Remove obstruction, replace airways.
2. Blower is worn or damaged.
Heater requires repair. In most cases cost of repair is comparable to the price of brand-new heater kit. It makes sense to replace the entire heater.

If you see a thick white smoke at the beginning of combustion cycle of Espar, Webasto, GC or similar heaters – it’s time for maintenance. Normally, your heater needs cleaning and replacement of quick wear components, such as burners/atomizer screens, glow pins, gaskets etc., after every one thousand hours of operation. If you don’t do this – your heater will become less efficient, will smoke more and more, start having flameouts and ignition faults and, eventually, will lock itself out.

The main reason for a thick smoke at the beginning of combustion cycle is accumulation of soot on interior walls of heat exchanger.


Heater smoking due to soot deposits

Heater smoking due to soot deposits

Diesel models are more susceptible to smoke problem than gasoline models due to presence of paraffin and other additives. This issue is resolved simply by brushing and washing the interior of heat exchanger with Carb Clean or other suitable chemical. One important thing to keep in mind – heat exchanger gaskets must be replaced every time you take the unit apart. If you reinstall old gaskets after maintenance – they will start to leak.


How to Extend Heater Life and Reduce Contamination


Fuel quality is the key to long life of any fuel-fired heater. Nothing affects its performance and reliability more. Other factors, such as power quality and quality of install, also play their role. Here’s the list of the most important things to follow:

  • Never use Diesel 911 or other fuel additives. They are #1 cause of contamination.
  • Run diesel heaters on heater kerosene, if possible. This may double life span of consumable comonents and improve performance.
  • Run gasoline heaters on high octane gas with low or no ethanol. Ethanol contaminates gasoline heaters.
  • Make sure your battery is good and charged. Old batteries may cause heater to fail.
  • Refer to help of experienced professional when install and service your heater. Trade experience plays crucial role in heater’s performance.


Ignition Faults and Flameouts


While smoke problem is hard to ignore, the other problems like ignition faults, flameouts and loss of efficiency are, sometimes, hard to notice. The root of these problems is usually the same – accumulation of carbon inside burner/atomizer screen and around the glow pin, as well as decomposition of the burner itself. All manufacturers recommend replacing the burner every 1000 hours of operation, which is equal, roughly, to two seasons of average use of the heater.


Other Causes of Smoke.


If excessive smoking of the unit is observed througout the entire cycle of the heater – you are likely to have a problem with the position or integrity of combustion impeller. That means that the combustion chamber does not get enough oxygen to burn all the fuel it has, and part of it escapes as a smoke. Typically, impeller gets damaged when heater’s operation is abrupted without completing its shutdown sequence (i.e. due to loss of power or incorrect installation/wiring). This problem should be resolved by a trained technician, according to the service manual for each particular model.

Other possible reasons for excessive smoking of the heater during its operation are obstructed, damaged or kinked intake or exhaust ducting of the heater. In all these cases we recommend to get certified help as soon as possible and refrain from using the heater.

Combustion impeller damage

Impeller damage due to sudden loss of power during combustion cycle

We Are Here to Help


If it’s time for your heater to get serviced, we can help you and refer you to the certified and trained professional in your area. We also provide maintenance kits for all our heater models and several models of Espar and Webasto heaters. Feel free to contact us or our dealers for details.

Excessive smoking of Espar and Webasto heaters - cause and remedy

Excessive smoking of Espar and Webasto heaters – cause and remedy