Westerbeke W13 heat exchanger

The Westerbeke W13 heat exchanger is very easy to service. It is located on the aft end of the engine and looks like a round can mounted crosswise to the engine, near the top of the engine. It’s about 12″ or 15″ long and about 3″ round.

On the A28 (8.5) it is usually possible to service the exchanger while it is still installed on the engine.

It is necessary to drain the engine coolant first, and there is a small drain cock on the heat exchanger for this purpose.

There are two caps, one on each end of the heat exchanger, which are held in place with a single screw through each cap. If you remove these screws, the inner core can then be removed for cleaning. It may not be necessary to remove the core as you may well be able to see any problems once the end caps are removed.

You may want to pick up a set of gaskets for the end caps before tackling the job as it is likely that the ones currently installed will be destroyed in teardown. Alternatively, you can make your own using the existing as a pattern or taking it from the end of the exchanger, and then cutting them from an old bicycle inner tube.

Be careful not to over-tighten the screws when re-assembling as the caps are made of copper or brass and will crack or deform easily.

Written by Bill Fleming