There is no chore onboard more dreaded than having to fix a constipated head. The bad news is that the types of heads commonly found on most boats plug up with great regularity, especially if used frequently. We know one couple that actually cut their cruise short because they tired of repeated head rebuilds.
Certain things aggravate the problem. Improper training of crew and guests as to what can, and can not, be put in the head is usually the number one problem. Poor installation with long complex hose runs, hoses with inadequate bending radiuses, or lack of maintenance exacerbates the situation.
Even when operated under ideal conditions, most small double-action head pumps eventually balk. Salt-water calcium build-up takes its toll. Solids settle in low spots and solidify, clogging hoses. Mechanical parts inside the head pump eventually wear out and require replacement. The first line of defense should be routine maintenance. ®
Suspect any odors from the head. Often this means marine growth or unflushed solids are plugging up the hoses. ®
Put a little white vinegar down the head each week. It helps dissolve calcium build up and kills most odor causing bacteria. A bit of laundry or dishwashing soap helps clean internal pump parts without damage, and a dollop of baby oil or mineral oil helps lubricate them. Never put drain cleaners or petroleum products down the head unless you intend to replace it next week.
A smear of non-petroleum grease (Teflon is best) on the pump shaft helps seal and lubricate the packing. Use this lubricant on the nuts and bolts that hold the head and pump together too, so that comes apart when it finally needs service. ®
When a little bit of resistance in the pump first appears, it is the time to investigate and repair. Don't wait for it to fail completely or you will inevitably wind up with a problem even worse, at a most inconvenient time, and with the biggest possible mess. With most small dual-action head pumps, the routine goes like this:
Close both seacocks and any valves to the holding tanks.
Assemble the head repair kit that you always carry onboard, along with tools, a bucket one-third filled with water, rags and paper towels.
Remove the pump from the head and put it in the bucket. If the unit has a "joker" or "duckbill" valve in the output tube, remove it and throw it in the bucket too.
Mop up the mess and take the bucket somewhere safe to disassemble all the tiny parts. Use the manufacturer's exploded parts diagram or make notes so that you can put it back together properly. Clean the pump body thoroughly as you pull the insides out.
Don't waste much time inspecting or cleaning the old valves, seals and screws - just replace them with new. If your re-build kit doesn't come complete with all the parts, make a note to add those to your list for next time and clean the old ones as well as you can.
Reassemble the pump.
Check the intake and outlet hoses for obstructions by opening the seacocks one at a time and applying air pressure with an inflatable dinghy bellows pump or something similar (blowing using lung pressure, not advised).
Put the pump back on the head, reattach the hoses and test.
Wash (preferably shower) thoroughly with antibacterial soap.
Perhaps, in the long run, the least offensive way to handle problems with dual-action head pumps is to sell the beast at a flea market and replace the entire head with one that works. When Eric and Susan Hiscock were building Wanderer V, they raved about the value of Blake's patented LaVac Zenith toilet. Based on that recommendation, we installed one on Quartet. Sixteen years later, through ownership of Cirrus II and Peter Rabbit, we are about to install our fourth one on Sojourner.
The LaVac Zenith itself has no moving parts, but operates on a simple vacuum principle. It uses a standard 1-1/2" sanitation diaphragm pump that can also be used to empty the holding tank or double as a bilge pump in an emergency. We're not particularly careful about what goes into ours, and yet we've never had a clog. Repair parts for the diaphragm pumps are available worldwide and a total re-build takes less than a half-hour.
This comes complete with a Whale sanitation pump, but you must specify either a bulkhead mount or thru-deck style. The sole U.S. distributor is Defender, 42 Great Neck Road, Waterford, CT. Telephone (806) 701-3400, 1 (800) 628-8225, and their FAX number is (860) 701-3424.