Plumbing System Makeover
by Bruce Landsberg
One of the great things about our boats is the chance to make improvements. In some cases the factory economized to save money over the hundreds of boats they deliver or the previous owner had a great idea that doesn’t jibe with your way of doing things.
These three changes have significantly improved the plumbing system on Southern Comfort, a 2000 model MKII. This started as a pump and head upgrade with the manifold change being necessitated by the need for space but that turned out to be one of the most useful features of the upgrade.
More Powerful Water Pump
Water flow and pressure was a bit anemic from the standard Shurflo 2.8 GPM pump, especially at the swim platform shower.
I chose the new Shurflo Extreme™ Series Smart Sensor Pump™ 5.7 GPM pump. This new technology pump is MUCH quieter and the water flow is a significant improvement. It eliminates the need for an accumulator tank.
The photo below shows how the boat comes from the factory. The water tank manifold is located just ahead of the pump and resides under the settee in front of the galley sink.
Stock manifold and pump
And the next photo shows the new pump with the recommended strainer. Use the existing wiring – just cut the wires to the old pump at the Factory splice and re-splice. The 15 amp inline fuse that comes with the pump fits nicely into the sheathing that protects the wires. I put a placard next to the fuse to remind me to check it if there’s ever a fault.
Finished pump install
As you can see in the next photos, the new pump is significantly larger and would not fit unless the fresh water tank selector manifold was moved.
Comparing the old and new pumps
Consumer note: Shureflo has two nearly identical pumps Extreme 5.7 pumps on their website. One is for RV use and one is for marine. The marine unit costs more, naturally, but has different internal components and is ignition protected. There is only one number difference in the model number so be careful when ordering.
Electric wire sheathing is available for significantly less at home improvement centers than in marine stores.
More Accessible Water Manifold
As mentioned above, the new pump would not fit without moving the manifold. In factory configuration, when a tank goes dry you must pull up cushions and move access panels to switch tanks – there must be a more convenient way!.
I mounted the manifold under the stove, where there is a small teak shelf that served no particular purpose on our boat – accessible but out of the way. Figure 4 shows the shelf box removed – just remove 4 Phillips head screws. There is plenty of space under the stove. [The hose that shows under the stove is for the refrigerator drain and has nothing to do with this project.]
Hole under stove
The water tanks should be empty to avoid “aquatic surprise” syndrome – a lot of water in the bilge. Disconnect the hoses, remove the old pump, strainer and manifold assembly. If it’s not glued together, as mine wasn’t, you may be able to reuse some of the parts. Mark the hoses with a marker or tape so reassembling is easier.
Parts:
- You’ll need about 5 feet of ¾” reinforced hose and a coupling to tie in the bow tank to the new manifold under the stove. If the existing hose is in good shape from the aft center tank you can cut it and use to run from the pump back to the manifold. If not, you’ll need another 5 feet or so.
- ¾” AWAB hose clamps - These are more expensive than the perforated kind but are much less likely to loosen or to tear up your hose. They’ll last a lot longer too.
- Three 1” valves, as shown in Fig 5, PVC parts and threaded barbs as shown. All this came from a home supply store.
- A bag of 1” copper pipe hold downs as shown in Figure 7A
- A number of ½” #8 stainless Phillips screws to secure the pipe hold downs.
- Teflon plumbing tape to secure threaded connections
- PVC glue and cleaner
- about 1 foot of 1.5” hose to act as chafe guard
Tools:
- Electric drill – preferably variable speed
- 1 5/8” hole saw
- nut driver and socket for hose clamps [screw drivers are OK but make a more secure connection with the nut driver]
- Screw driver - Phillips
- Dust mask, goggles and shop vac recommended
- Measuring tape
Remove the drawer units under the galley sink to gain access to this area. Again, it’s nothing more than removing the screws in the frame face – put the screws in a cup so as not to lose them.
Now the messy part: There is a fiberglass bulkhead that has to be drilled for the hoses to pass from near the water heater to under the stove. Position the holes as you wish but not too close each other to avoid weakening the structure and have at it. Strongly suggest a respirator or good quality dust mask, goggles and a shop vac for this operation. Once the holes are drilled and the dust cleaned up, cut your 1.5” chafe hose and insert it in the holes, then push the water hoses through.
Holes drilled in bulkhead
Since the new manifold position is farther aft, the two aft water tank hoses should reach without a problem. The bow tank hose and the hose from the pump to the manifold will lie next to the hot water heater. The aft starboard water tank hose which used to pass ahead of the hot water tank to the manifold will now be routed under the sink and aft of the hot water tank.
Looking from water heater aft to stove bulkhead
Build the manifold carefully so that there is just enough space for the handles to move in a full arc but not so far apart that the unit will not fit into the teak shelf. Measure three times - cut once. Figure 8 shows why the measuring is important! Suggest using a cardboard template to practice with that simulates your teak box.
Front shelf with lettering
Dry fit the manifold [no glue] together, screw the threaded parts together without Teflon tape and when it’s all done, check the fit to the shelf.
Ready to mount
When you’re satisfied with the fit, drill the holes in the back of the shelf. The wood is about 3/8” to ½” thick and you may want to make the hole a little oversize so the handles will move freely. If you’re uneasy about that strategy, then cut to size and use a Dremel tool or file to shape the holes so the handles move freely. Check the fit again and once you’re sure – glue the PVC and reassemble the threaded parts using Teflon tape.
Mount the manifold to the shelf, attach the hoses and secure all hose clamps. A little liquid dish soap will help coax a hose on to the hose barbs. Put some water in the tanks, turn on the pump and test the system looking for leaks. All tight? Then remount the shelf and the drawer unit under the Galley sink.
Water manifold under stove
The New Head
The standard Jabsco head that Catalina installed is adequate but only barely especially for solid waste of any consequence – and that’s all I’ll say about that. It’s complicated for guests to use so we kept a checklist on hand for our friends and mumbled the instructions hurriedly for our enemies.
The procedure described here is for an electric head installation but much would apply to any head swap. We chose the electric Sea Era macerating head, marine model, since it fit the space on the C36, was available in a fresh water version to keep odors to a minimum and works by simply pushing a button. The two units are shown side by side in the living room – quite the conversation starter! A household bowl size would also work – personal preference.
Two heads
Parts
- Several feet of reinforced 3/4” hose
- AWAB Clamps
- 4’ of Sealand Odorsafe Plus hose
- about 40’ of wire – you’ll need to measure this and size it for your boat
- A circuit breaker for the head
- Various electrical fittings & wire sheathing
Tools
- Same as above
- Hacksaw
- Possibly a Dremel tool
Remove the opening cabinet drawer behind the head to gain access. Remove the old head by unscrewing the lag screws.
Headless
Now is a great time to replace the old waste hose between the head and the holding tank. Four feet of Sealand’s Odorsafe Plus hose does nicely. It’s pricey but much less prone to permeation than the rubber type. Recommend a hacksaw to cut it to length. Use AWAB hose clamps.
Hose
Use the existing lag bolts and washers if they’re in good condition. Human Factors point: While the old head was mounted symmetrically, it wasn’t optimized for use. As shown in figures 14, I angled the head slightly to improve both seated and standing positions. You’ll want to experiment to get the angle that works best for you. The Sea Era has the ability to rotate the bowl 90 degrees to position the macerator and hoses to match your installation, which I did on Southern Comfort.
Head angled
The wiring is straightforward. But be sure to follow instructions on proper size for the round trip from the nav station to the head. It’s longer than you think. Best way to measure is to get a piece of line and run it from the nav station, under the battery compartment, over the bilge, past the holding tank, over the river and through the woods to grandma’s house! You may have to enlarge the space through the bulkhead as shown in Figure 13. which is shared with the vent hose. I used a drill and Dremel tool to enlarge. Again, wear a respirator or dust mask.
The solenoid for the fresh water line is located under the sink and the water line is Teed into the cold water line for the sink – This seemed the best place, taking into account both plumbing and electrical needs. Consider putting a shut off valve in the line. I used one from the old water manifold.
Fresh water solenoid
I mounted the flush button within easy reach on the front of the vanity. Next project will be to get a nameplate professionally lettered.
Flush button
The installation requires an anti-siphon valve, included with the head, which is located in the cabinet behind the head –mounted in the same place as the valve for the original head.
Anti-siphon valve
The job is complete, and the sum is greater than the parts: We have great water pressure, a wonderful, non-clogging simple head, and easy access to the water tank manifold. All the comforts of home - on the water.
Finished, it gives us all the comforts of home