Plumbing Repairs Winter

New Freshwater System

I’ve been drafting and researching the freshwater system for a few months when I have spare time and have come up with some solutions I would like to share. I’ve decided to install Sharkbite branded fittings so replacing a pipe or fitting is as easy as possible. Also the piping is blue from the holding tanks and red from the hot water tank. This will make tracing easy as well at no extra cost. Inside of the engine compartment on the hot water side I have enclosed the piping with foam pipe insulation to help prevent heat loss in the unheated portion of the boat.

Tank attachments

The plumbing from the deck fitting to the tank is 1 1/4″ sanitary hose and schedule 80 PVC with hose clamps. Removing the hose is simple as the barb tank fitting is not exactly 1 1/4″ which means removing the tanks for cleaning will be a little easier over time. I contemplated over going with 1 1/4″ pex but decided to make the deck plumbing more permanent. The main argument? It’s a pain in the ass to route the hose from the deck fitting to the tank. Hopefully I never have to replace the hose.

The tank vent is 1/2″ npt so I chose to join the vents with a ‘T’ fitting and pex tubing, then at the end opted for a brass breather vent to prevent debris from entering the supply line and also close the vent down as small as possible to prevent any water overflowing out of the tank from flowing at the same rate as the rest of the system. The idea being that the tanks will be full of water and start filling up to the deck fitting so you know when to turn off the water. The vent  only leaks a small amount of water out into the bilge until you can run water through the galley sink to drain out the deck fill hose to a level that prevents the vent from spewing water. The alternative would be to keep an eye on the vent and wait until you see it leaking water and then run up and turn off the water. At that point you’ll have likely gallons of water already in the bilge and then need to clean out the primary bilge after every filling. The photo below is only one example of a vent fitting and I accidentally opted for something different which is simply a screen inside the fitting with a tiny hole drilled into the side of the nut portion. It turned out to be the right amount of air for filling with a garden hose at full flow and displacing the water in the tanks while consuming the supply. The interesting thing about vent fittings is that there isn’t already a solution out there and everyone is left to their own accord on solving this problem.

Freshwater tank breather vent fitting allows air in and out but prevents debris from entering the system
Freshwater tank breather vent fitting allows air in and out but prevents debris from entering the system

A ball valve for each tank will allow me to isolate the tank output for any reason. The previous valves were sitting low enough to be in contact with water in the bilge. The new valves sit three inches above the bilge instead of one inch. The photo below shows the ‘T’ above the tanks but I decided to move it down so the second tank would fill once the first one was half filled.

The freshwater tank assembly using pex Sharkbite fittings. Fill hose barb not attached yet.
The freshwater tank assembly using pex Sharkbite fittings. Fill hose barb not attached yet.

Tank to the pump

A water meter tracks the total amount of water that has passed through the freshwater system. This way if I do end up filling the tanks I can know exactly how much water I have left without eyeballing it. I can also log usage for replacing the water filter or simply to keep track of my daily and weekly average water use. I thought about getting a digital display but felt analog would be just fine since I will be in the engine room often enough. The meter is quite massive and heavy at likely five pounds but looks like it will last for the duration of Satori’s life and provide dependable service without requiring any electricity and very little maintenance. It’s located in an inconvenient place for reading the meter but I remedy this by taking photos of the meter for logging using my iPhone, which seems to be better for keeping track. Also the mount had to be custom built as you can see below it is odd shaped.

Inline water meter
Inline water meter

A strainer eliminates any large particulates that make it into the tank or rust that may come from the tank itself. This will attach to the input port of the pump. A 4.5 gallon per minute, variable speed pump delivers water pressure (35 psi) and freshwater throughout the boat. Variable speed pumps eliminate cycling using a solid state pressure sensor to regulate flow. Simply turn the water to your choice of volume and the pump will maintain a constant pressure   flow without the need for an accumulator.

Jabsco Sensor Max   variable speed pump with strainer
Jabsco Sensor Max variable speed pump with strainer

Pump to manifold

A 3.5 gallon per minute freshwater whole system filter eliminates most contaminants and provides clean freshwater at a reasonable cost. The filter will not eliminate the need for potable water and I would never want to introduce water that has not been treated to eliminate hazardous organisms such as giardia or cryptosporidium, which would make anyone ill from drinking. It will filter water down to .2 microns which eliminates everything I’m concerned about from most potable water sources.

3M B3 Water Filter - 3.5 gpm, .2 microns and 6 month/15,000 gallon lifespan
3M B3 Water Filter – 3.5 gpm, .2 microns and 6 month/15,000 gallon lifespan

I debated on purchasing a manifold of solid copper with sharkbite attachments but the manifold presented a few problems I did not like. First off I was stuck with adding a 3/4″ to 1/2″ sharkbite reducer just to install the manifold into the system. Also the manifold seemed a bit excessive for simply distributing freshly filtered water so I opted for “T” fittings instead. The cost is about $36 for the manifold and $6 for the reducer but only $12 for three “T” fittings.  They can be fitted closely together and accomplish the same thing and I can just add another “T” if I want to tee into the line pretty much anywhere I want.

Filter to hot water tank

A check valve is placed inline between the filter and the hot water tank to prevent hot water from back-flowing into the cold water lines. Since I’m running a variable speed pump, no need for an accumulator.

Currently I’m plugging the pex tubing straight into the hot water tank and then to flexible hose with Sharkbite fittings on both ends. I plan to replace the pex with copper on the tank end for long-term use as it’s better suited for near tank plumbing.

Hot water tank to radiant heater

A temperature gauge at the heater outlet allows me to visually see what the current temperature of the hot water is at any moment. If the tank has been off for some time I can check to see if it’s ready. If the tank registers unsafe temperatures I can switch the tank off or possibly add a mixing valve if necessary. Either way it’s added peace of mind.

Sharkbite temperature gauge
Sharkbite temperature gauge

A pressure gauge at the heater outlet allows me to monitor hot water pressure for the same reason I am monitoring the temperature; peace of mind for just a little extra money.

Sharkbite temperature gauge
Sharkbite temperature gauge

After the gauges I have a 2.2 gallon per minute solar pump so hot water is circulated throughout the boat and allows for instant hot water for any of the faucets on the boat. This prevents wasted water while waiting for the hot water to warm up in the bathroom, which is common in regular households with hot water tanks. The pump is wired with a simple rocker switch that can be operated from the bathroom in case the hot water heater is on and I’m not running the forced air heater to supply instant hot water to the bathroom sink as needed. I debated over the switch location and this seems to be the most logical location as it also supplies the heater with power in the same circuit as the pumps.

Circulation pump
Circulation pump

A ‘T’ sends hot water to the cockpit and then out to the rest of the boat to begin a recirculation loop. The loop heads forward with another ‘T’ to the galley sink and down under the floor in the salon on the port side to provide a little extra heat to assist in heating the cabin from below the floor. The loop then heads up to the bathroom sink and another ‘T’ provides hot water for the bathroom sink. The loop then heads to the forward berth and supplies the Dickinson Radex forced air heater with hot water to blow warm air into the forward part of the boat.

Dickinson Radex forced air heater
Dickinson Radex forced air heater

Heater back to hot water tank

The loop then heads back to the salon under the floor on the starboard side to provide a little more heat and finally back up to the hot water tank, which completes the hot water circulation loop. This is  also known as an open hydronic system.

All of the plumbing fittings are ordered from PexSupply or at my local Home Depot, which carries most of the basic Sharkbite fittings. Home Depot does not have any manifolds, gauges or check valves so if you’re planning on building a similar setup, expect to buy some parts online and the basic fittings as you need them at your local Home Depot. I underestimated the amount of elbow fittings I would need and suggest that if you’re going to use Sharkbite that you buy plenty of these parts to make the routing much easier. Also, Sharkbite fittings are expensive but when I did the math for hose clamps plus the same barb fittings it seemed about a dollar more per fitting. The pipe is less expensive than quality marine water hose so it might only be a little more. I’m not entirely finished with this project yet as the plumbing and electrical needs to be secured and some rerouting would be nice to tidy the engine compartment but it’s nice to have water back on the boat once again.

Finishing this project, I plan on repairing my Dickinson Pacific diesel stove by replacing the water coil that provides hot water to the hot water tank without the need to run electricity. The hydronic system with the heater fan on and pump draws less than 4 amps of power so it should prove to be very nice while away from shore power. I’ll follow up later when the heating coil project is complete. There is also an option to plug in a calorifier that uses hot water from the engine to heat the hot water tank. It would be nice to have another source of heat for the tank and the hot water tank already has fittings so I may also plumb in another pump for this as it does not look too difficult. I’m still debating the need so I’ll reassess once my Dickinson coil is in place.

This weekend is the Seattle Boat Show, which puts me into another project of getting a new chart plotter and radar. I’m hoping for a discounted deal at the show. Wish me luck!

7 replies on “New Freshwater System”

Thanks Carl! Yes, the deck fill is on the starboard side at the bow portion of the deck. See “Tank attachments” at the top of the post.

My 2 cents… Save your hot water piping and safety with a mixing valve. Go with a closed system to separate your domestic and heating water separate and get hotter water to your heaters. Some recommend a heat exchanger as well for the heat side. Reason i dont like the open system is the exposure to non nsf components (heaters) and the engine temp heat in the pex and scald risk at fixtures. Just my opinion.

Bruce, I appreciate your advice. I debated on starting out with a mixing valve but when I brought the hot water tank to temperature it read 120 F and stayed there. I suspect that when I do install the loop in the Dickinson stove that the water would raise to considerably more and I will likely install a mixer for that purpose. As far as NSF (safety), I made sure that everything was intended for potable water. The Radex heater is plumbed through copper and is the only component that isn’t part of a normal potable water system but I made sure the heating coil was copper for potable water.

Hey Tony:
I’ve been trying to find you and stumbled onto your website – Incredible! I’m in total support of you following your dreams – go for it while you are still young and capable.
Let’s get together for a beer – I still owe you one, call me anytime at 425-***-**** or cell 425-***-**** (although it is not always with me when I need it). I’d like to see your boat. I’m not sure if you knew Dave Breckey at REI who lived on a large sail boat with wife , kid and dog. And Paul Renhard was also into sailing.

Hey Tony,
Did you get new ss tanks, or are those the original. I know you spoke about maybe getting new tanks, but didn’t see the update. Also, just thought, on you your supply (out) to faucets could you have used a clear tubing (vertical) for the height of the tank and wouldn’t have that worked as a gauge level?

Rob & Sophia,

The tanks are original with new deck plates and fittings. I might weld new stainless clean out plates if I can talk a friend into it. He offered so we’ll see! I’m concerned that the fittings would fail in a knockdown so if I’m going to serious seas I will probably remove them and have them welded. At least they can be easily removed now.

I could have a vinyl gauge for quick checking of the tanks but so far the meter has been awesome. I use my iPhone to take a photo of the gauge and then put an entry in usage my log, do the math and can see how much I’ve used and how much I have left without inspecting the tanks at all. Honestly though I don’t know exactly how much the tanks hold. I filled them to the brim this time so when they run dry I have my max fill level and can then make future calculations on remaining supply. The meter also has a digital option that you can wire to an external display but I decided analog is fine. Unless I’m counting every ounce I don’t think it is necessary.

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