Clearing Blocked Heads

Book Extract

Why It Needs To Be Done
Blockages can occur because objects other than human waste and soft toilet paper have been put into the toilet bowl. Nautical tradition requires the person responsible to clear the blockage.

When It Should Be Done
When it’s become blocked.

Tools Needed
Usually no more than a screwdriver and a pair of rubber gloves.

Where To Find It
In the toilet pump.

 

First make sure that the seacocks are open and that you are not trying to pump against a closed seacock.

Whale Mk 5 / Henderson Mk IV Diaphragm Pump

Pump through then close the toilet seacocks.

Contaminated toilet waste will discharge from the front of the pump

Unscrew the pump access cover (photo A).

Remove the cover (photo B).

Check the inlet valve for blockage (photo C).

Check the outlet valve for blockage (photo D).

If you need to go further than this, see more on page 103.

ITT Jabsco Toilet Pump
Make sure that the dry bowl changeover control is fully one side or the other. If it isn’t it will give the symptoms of a blocked toilet.

Close the toilet seacocks.

Remove the two screws securing the discharge flange (photos E & F).

Remove the four screws securing the pump to the base (photo G).

Lift off the pump assembly (photo H). 

Lift off the bottom valve/gasket (photo I).

Remove the joker valve (photo J).

Clear the blockage and reassemble.

 

© Not to be reproduced without written permission from Fernhurst Books Limited.

Simple Boat Maintenance was written by Pat Manley. Pat was a keen sailor, and must have had one of the most "self-equipped” boats afloat. He was a technical contributor to Practical Boat Owner magazine, a Fellow of the Royal Institute of Navigation and an RYA Yachtmaster Instructor.