9 October, 2017
Not all heaters are created equal.
When looking to buy a diesel heater to extend the summer sailing season some people are understandably tempted to try and save money by buying a cheaper road version of the Eberspächer or Webasto diesel heaters. This has become even easier to do when many are offered on sites such as Ebay or Gumtree describing them as marine units. Don't be fooled into thinking the manufacturers are selling the same unit but higher priced just because it has the word ‘marine’ in front of it. There are differences and they are important ones when installing in a boat.
The marine version of these units use stainless steel fittings instead of galvanised ones. The fuel hose must be copper not plastic and no inline plastic fuel filters should be fitted. The stainless steel exhaust hose must be lagged and comes with a longer length and most importantly, it comes with a skin fitting to take it safely outside of the hull. There are other differences but this is not intended as an installation instruction only a cautionary note.
In the photo above the owner had installed a road going version of the heater in his motor boat. The exhaust was not lagged - even though it can reach temperatures up to 200∘C near the heater. There was no skin fitting, just the hose poked though an open hole with no clamping. The hose also had a corrosion split that was leaking exhaust fumes directly into the living space.
Whilst it is possible to fit your own units you must do your research to find the correct way in order to make the installation safe and if you aren't sure, please consult a professional.