Diesel bug in Eberspacher heaters
The winter is approaching and boat owners will be looking towards firing up their Eberspacher heaters to keep warm.
Eberspacher diesel powered heaters are one of the most popular forms of heating in use on narrowboats and it is likely that the dreaded “DIESEL BUG” will make itself felt this winter as the stocks of lower sulphur content red diesel work their way through the canal system.
Diesel bug can be prevented by using additives like Marine 16 but the bug itself thrives on water, and the lower sulphur content diesel fuel has a higher water content.
So even if the bugs are killed there will stilll be some quantity of water in the tank as the diesel breaks down and the lower temperatures of autumn causes condensation to form and sink to the bottom of the tank. This can cause your Eberspacher ,or other type of heater, to fail to ignite or run properly
A combination of diesel fuel polishing and additives is probably the only economical way of keeping your diesel fuel in its best condition.
Here is an extract from the Inland Waterways Technical Bulletin number 281 –
“Red diesel” on the inland waterways is now ultra-low sulphur gas oil, a fuel used specifically for ‘off road machinery, agricultural equipment and inland waterways. This fuel can contain a low percentage of FAME (Fatty Acid Methyl Ester) commonly known as bio fuel.
Although this fuel is generally far better quality than the previous high sulphur gas oils that were used it still needs to be looked after and kept clean and fresh.
Fuel condition is extremely important to a diesel fired heater. Example: If a heater is suffering from one of the problems we have just covered, the carbon build up can be accelerated by the condition of the fuel.
Degradation: Gas oil will start to degrade after approximately 6 months this is where the oxidation in the fuel causes heavy molecules to separate in the fuel and begin to sink to the bottom of the tank forming ‘sludge’ and varnishes. Water will also start to separate from the fuel and collect with the water generated by condensation. The cetane value of the fuel will begin dropping. This process starts to happen before the fuel even leaves the refinery. Fuel is
generally refined abroad and then transported by tanker ship to the UK where it sits in the main storage depots tank until it is transported by road tanker to the smaller distribution depots, from here it is transported to the marinas fuel tank, then finally into the boats tank. That is normally the last time that the fuel will get mixed or shaken because unlike sea boats or road vehicles, the inland waterways tend to be calm so the fuel is allowed to sit and separate.
Eventually there will come a point when the cetane value of the fuel falls so low the fuel will no longer ignite in the heater. DO NOT take fuel for granted or overlook it when fault finding the heater. If a fuel additive has been added make sure it is mixed in and not just tipped into a tank and allowed to sit there.
Diesel bug will cause problems with a heater. It will normally be found as a black sludge in the pump filter. This will alter the fuelling at the heater by restricting the fuel filter, ultimately to the point where the heater will no longer run. If additives have been added check the fuel has been agitated regularly. Some fuel additives will separate out if the fuel is not stirred or shaken up regularly.”
Don’t let diesel bug stop your Eberspacher heater this winter!