It’s all a bit mucky inside
QA specialist examining our boat’s heating thinks we have contaminated fuel coming from the tank – the central heating fitting is leaking rusty coloured fuel and he has taken it for examination. Will I have to drain the fuel tank? If so, how do I go about it? Or is there anything else I can do?
EMMA PRITCHARD, via email
ATONY REPLIES: A few years ago this would have been a DIY job involving buckets, empty oil drums, a pump if the boat does not have a tank drain, hoses and mess. Nowadays a number of companies will come to your boat and ‘polish’ the fuel – pump it from the tank through ever finer filters (pictured above) back into the tank until it is clean. The best ones will look for signs of diesel bug and also add a biocide if needed.
This is by far the easiest way, and will also remove any water, although the cost is likely to be in excess of £150. Get the filters and water separators on the engine and central heating system cleaned or replaced at the same time (see page 70).
You don’t mention jelly-like substances in the fuel (signs of bug), so I suspect that it may be no more than water contamination. You can (and I recommend that all boaters do this every spring) rig up some form of pump or siphon (or even a wetand-dry cleaner with a small pipe fitted) to ‘vacuum clean’ the bottom of the tank to remove any water (you could easily have several inches) or bug that has collected.
If you find any signs of reddish, grey, or black jellylike stuff in a fuel pipe or filter you probably have fuel bug so treat the tank with a biocide additive, change the filters and clean any water traps. Then be ready to change the fuel filters several times if they block.