We did a massive refit this winter of the fresh water system, new hatches for plumbing access, UV water filter, sinks, water heater, composting toilet, cockpit and anchor fresh water wash-down gear. Almost all of the old grey polybutylene was replaced, mostly with 1/2" PEX piping, widely available at any plumbing/hardware/home improvement store.
Disclaimers
Mark-In-the-Box: getting to some of these parts was challenging for a "not small" person.
It is HIGHLY satisfying now that it is done, but it was a LOT of work, and I spent most of the winter doing it on weekends. I probably did 20-30 runs to Home Depot, Lowes, West Marine. I don't think I would tackle a job like this if I was not so close to a Home Depot, Lowes, or a big hardware/plumbing store. Even with lots of planning, there were always many unforeseen things I needed. We also live 7 minutes from where our boat was moored, and I happen to have almost every tool known to mankind. Those things helped too.
Here is what my finished system looked like. Photo taken from the galley sink, with galley sink removed.
Okay, it looks a bit like Frankenstein, but I couldn't figure out how to make it lay out any cleaner.
Below is a photo with the parts labelled.
The little arrows above show the usual flow directions of the water. And here is a key to what those things are:
Why PEX Piping with Push-On Fittings?
There are other alternatives that would have worked fine. And reasonable people will disagree. I chose this because:
I did not exclusively use PEX. I used the clear, flexible PVC tubing several places because:
Why a UV Filter?
I've been drinking water straight out of boat tanks for 30+ years. I probably occasionally got sick because of this, but I don't remember any specific times. I did get amoebic dysentery once in Spain. While it had a different cause, I'm not eager to repeat that experience. We plan on doing more voyages out of the country, and we want to not worry (too much) about water sources. Once in Thailand we saw a scummy livestock pond that fed the water pipes which ran out to the docks. With this system we have at least it removes the danger of that situation.
We eventually plan to install a watermaker, but even with very clean water in tanks, crud, bird poop, bugs, get washed down into tanks. For our drinking water, we wanted something better.
I'll do a separate thread about our rationale and alternatives we considered, but we ended up installing a UV water filter. It zaps & kills viruses/microbes/bacteria, etc. There is an 'advanced pre-filter' which strips out "lead, heavy metals, chlorine, mercury, carcinogens, and other contaminants, as well as turbidity, unpleasant odors and tastes.". The bottom line is the water that comes out tastes really good and is pretty darned safe.
We settled on an Acuva ArrowMAX 1 UV-LED because it is compact, has low power consumption, and a dedicated faucet with a light that turns on so you know the UV filter is engaged under the counter. The model we got is not super high rate of flow, but we just put our water bottles under the faucet and let them fill while we are doing other things. We recently had been getting our potable water via plastic bottled waters from the store. This helps us reduce "single use" plastics.
What the Heck is a Thermostatic Mixing Valve?
Note from the future: This is not a good idea, and we took it out. I think it would work fine under constant pressure. However, when when the water pump kicks on (and the pressure increases), it sends a very cold burst of water through the system. It still eliminates the 'scalding water' issue, but makes showering too thrilling.
Old Note (before we used it much): We used to have scalding hot water (190+ degrees F), out of our faucets. This is because when the engine is running we have engine water heat exchanging with the hot water heater. When the engine wasn't running, our water was around 140 degrees using electricity for heat. Nowadays, the accepted "non-scalding" temperature for hot water is around 120 degrees.
To accommodate the varying temperatures in the tank, I'm trying a "thermostatic mixing valve". This valve mixes cold water with the hot water from the tank to put out a consistent 120 degree water. It adjusts "on the fly". Further - it functionally expands the size of the tank because you can set your tank thermostat to the higher side (like 180 degrees), and you get a lot more water out of it at 120 degrees, once it mixed.
On our boats, because of the variations in the temperature of our water heater's water, and the size limitations, it seems like a perfect place to use of thermostatic mixing valves: making the temperature consistent and increasing the volume. I've never seen them used on boats, and I'm not quite sure why. I guess we'll find out.
I got a Cash Acme 3/4 Inch Tank Booster Water Heater with Thermostatic Mixing Valve. It also has an integral check valve for the water heater's inlet, and it is adjustable so you can increase or decrease the target temperature. https://www.amazon.com/gp/product/B00FBP2IPO/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
JABSCO's Ultra Max Model No. 59451-1012
I wanted all of these items, and JABSCO has them all in one unit:
Here is a close-up of the unit.
Head Plumbing
Obligatory before/after photos.
BEFORE: This is the plumbing inside the head vanity. I think this is all original 1983 piping. The mold is probably newer, though.
AFTER: Inside the head vanity. All the sewer piping is GONE because we now have a lovely composting toilet.
Disclaimers
- Working with electricity can kill you or someone you love. If you don't know what you're doing, get a professional electrician to help.
- Working with fittings and pipe, especially below the water line, can sink your boat. If you don't know what you're doing, consult with an ABYC-certified technician.
- In my previous life, I was a registered Civil Engineer (PE) and I designed/built water/wastewater systems. But I also do more stupid things than an average person and some of the following ideas might be straight-up dumb.
Mark-In-the-Box: getting to some of these parts was challenging for a "not small" person.
It is HIGHLY satisfying now that it is done, but it was a LOT of work, and I spent most of the winter doing it on weekends. I probably did 20-30 runs to Home Depot, Lowes, West Marine. I don't think I would tackle a job like this if I was not so close to a Home Depot, Lowes, or a big hardware/plumbing store. Even with lots of planning, there were always many unforeseen things I needed. We also live 7 minutes from where our boat was moored, and I happen to have almost every tool known to mankind. Those things helped too.
Here is what my finished system looked like. Photo taken from the galley sink, with galley sink removed.
Okay, it looks a bit like Frankenstein, but I couldn't figure out how to make it lay out any cleaner.
Below is a photo with the parts labelled.
The little arrows above show the usual flow directions of the water. And here is a key to what those things are:
- Main access door under galley sink, facing aft
- New access door under galley sink, facing forward, behind seat-back cushion
- Valves to control flow from water tanks. 3a is from V-Berth tank, 3b is from starboard tank.
- Preliminary screen filter (part of JABSCO Ultra Max)
- Water Pump (part of JABSCO Ultra Max)
- Accumulator/Hydro Pressure Tank (part of JABSCO Ultra Max)
- Advanced Pre-filter for UV Filter
- UV Filter. 1/4" outlet port is under this label and runs to the UV Filter faucet on the sink
- Valves/Stub-outs to feed main galley faucet. 9a is cold, 9b is hot.
- Thermostatic mixing valve. See description below. Note from the Future: this is not a good idea and I took it out, see description below.
- Hot water tank outlet. There is an anode inside the outlet we need to check each year, requiring access to this port.
- How water tank blow-off valve. Discharge tube runs to bilge.
- Valves for controlling flow to cockpit wash-down. Can blend in some warm water or turn them off.
- Tee which feeds 1/2 tube to cockpit wash-down.
- Engine hot water inlet/outlet for hot water heater heat exchange
- Hole thru which pipes (hot and cold) run to the Head, and run from the shower drain, and from the V-Berth water tank.
- Hose bib (not fully visible in this shot). For draining system, running hose, pressure gauge, etc.
- Drain hose for galley sink. Goes to 1-1/4" through hull.
- Circular black Access Plate for access to water heater's thermostat and heater element for maintenance.
- Drain pipe, white 1/2" PEX from Head Shower.
- Brace/Bracket to secure upper water heater body.
- We had tons of leaks, and we couldn't just leave the water pump on: it would constantly cycle and drain the water tanks into the bilge via leaks. We found and repaired some leaks but couldn't find others.
- We didn't have any sort of Hydro/Accumulator tank to buffer the flow. So any time you opened a faucet for even a tiny bit of water, the pump kicked on.
- The old grey polybutylene pipe has a storied past. It was widely used in the 1980s, very fast & easy to install, flexible, etc. But it developed tiny cracks and leaks. You can imagine what a mess that was behind sheetrock in houses. So it was also the subject of one of the biggest class action lawsuits from homeowners seeking reimbursement. As it happens, most of our leaks were in old iron/metal fittings, but since I was ripping everything apart, I wanted to replace it.
- We wanted to add a UV water filter so that we could still take on water from unknown sources in other countries, and generally not need to worry about drinking it.
- Our existing water heater (original, ~40 years old) was pretty much disintegrated and leaking. When I put a pipe wrench on it to take it apart, I didn't even apply any pressure and it crumbled apart and drained the tank into the bilge.
- We often had scalding hot water (over 190 degrees) spurting out of our spigot. Because the tank is also heated by the engine, when running. We installed a thermostatic mixing valve so that no matter the temperature in the tank, the water (theoretically) gets equalized to a consistent 120 degrees.
- The ~40 year old sinks and fixtures were corroded and leaking, and replacing gaskets could not fix them. It was deeper than that.
- We hadn't used the saltwater pump at the galley sink in our 10 years of cruising on Zia. In addition to trying to reduce the amount of salt inside the boat, the underwater intake for this faucet was also right next to the head discharge (a.k.a. raw sewage), which does not seem like a good idea for rinsing dishes after you wash them. Also, the line to feed this faucet runs from the head to the galley well below the waterline, and is made out of the famously leaky old grey polybutylene, which does not seem like a good idea from a "sinking the boat" perspective. Anyway, we were not fans and it was taking up space on our sink, and we wanted it gone. Reasonable people do disagree with this.
- We had also never used the manual hand pump for water, and it was taking up space on our sink. We always have a spare water pump aboard, and we can always siphon water out of the tank if both pumps fail or there is no electricity.
Why PEX Piping with Push-On Fittings?
There are other alternatives that would have worked fine. And reasonable people will disagree. I chose this because:
- It is super widely available (including other countries) and it has been used a lot over 20+ years.
- The piping is quite cheap, and it doesn't corrode.
- The push-on fittings cost a bit more, but I could barely reach most of these places. More elaborate fittings that required two hands or special tools were not as practical.
- The push-on fittings are also (sort of) easy to remove, so it is easy to change your mind on how you want to do something. Which I did often.
I did not exclusively use PEX. I used the clear, flexible PVC tubing several places because:
- Some runs of the old grey pipe would have been very difficult (impossible?) to do with PEX because of twists, turns, corners that the old pipe made behind cabinetry and flooring (sole). It would have required sawing, drilling of cabinetry, or tearing up the sole. None of which I wanted to do. Example: from the head to the tank under the v-berth. I used a wire snake to get PVC tubing into that run, replacing the old polybutylene.
- I also used the PVC tubing in several places because it would make maintenance easier in the future. In the photos you can see several places under the galley sink that I used it for this reason. That was a personal choice with debatable payback, but I'm happy with it.
Why a UV Filter?
I've been drinking water straight out of boat tanks for 30+ years. I probably occasionally got sick because of this, but I don't remember any specific times. I did get amoebic dysentery once in Spain. While it had a different cause, I'm not eager to repeat that experience. We plan on doing more voyages out of the country, and we want to not worry (too much) about water sources. Once in Thailand we saw a scummy livestock pond that fed the water pipes which ran out to the docks. With this system we have at least it removes the danger of that situation.
We eventually plan to install a watermaker, but even with very clean water in tanks, crud, bird poop, bugs, get washed down into tanks. For our drinking water, we wanted something better.
I'll do a separate thread about our rationale and alternatives we considered, but we ended up installing a UV water filter. It zaps & kills viruses/microbes/bacteria, etc. There is an 'advanced pre-filter' which strips out "lead, heavy metals, chlorine, mercury, carcinogens, and other contaminants, as well as turbidity, unpleasant odors and tastes.". The bottom line is the water that comes out tastes really good and is pretty darned safe.
We settled on an Acuva ArrowMAX 1 UV-LED because it is compact, has low power consumption, and a dedicated faucet with a light that turns on so you know the UV filter is engaged under the counter. The model we got is not super high rate of flow, but we just put our water bottles under the faucet and let them fill while we are doing other things. We recently had been getting our potable water via plastic bottled waters from the store. This helps us reduce "single use" plastics.
What the Heck is a Thermostatic Mixing Valve?
Note from the future: This is not a good idea, and we took it out. I think it would work fine under constant pressure. However, when when the water pump kicks on (and the pressure increases), it sends a very cold burst of water through the system. It still eliminates the 'scalding water' issue, but makes showering too thrilling.
Old Note (before we used it much): We used to have scalding hot water (190+ degrees F), out of our faucets. This is because when the engine is running we have engine water heat exchanging with the hot water heater. When the engine wasn't running, our water was around 140 degrees using electricity for heat. Nowadays, the accepted "non-scalding" temperature for hot water is around 120 degrees.
To accommodate the varying temperatures in the tank, I'm trying a "thermostatic mixing valve". This valve mixes cold water with the hot water from the tank to put out a consistent 120 degree water. It adjusts "on the fly". Further - it functionally expands the size of the tank because you can set your tank thermostat to the higher side (like 180 degrees), and you get a lot more water out of it at 120 degrees, once it mixed.
On our boats, because of the variations in the temperature of our water heater's water, and the size limitations, it seems like a perfect place to use of thermostatic mixing valves: making the temperature consistent and increasing the volume. I've never seen them used on boats, and I'm not quite sure why. I guess we'll find out.
I got a Cash Acme 3/4 Inch Tank Booster Water Heater with Thermostatic Mixing Valve. It also has an integral check valve for the water heater's inlet, and it is adjustable so you can increase or decrease the target temperature. https://www.amazon.com/gp/product/B00FBP2IPO/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
JABSCO's Ultra Max Model No. 59451-1012
I wanted all of these items, and JABSCO has them all in one unit:
- Screen Filter before the pump. Keeps big things out of the pump, and keeps them from damaging the pump
- Water Pump
- Pressure Switch to keep the system operating between 20 and 40 psi
- Accumulator (hydro pressure) tank. Many boats like ours don't come with these. It is essentially a small tank that is filled with air that is separated from the water with a diaphragm. It acts like a little buffered storage area. So if you open a faucet to fill a cup of water, the pump won't necessarily kick on.
Here is a close-up of the unit.
Head Plumbing
Obligatory before/after photos.
BEFORE: This is the plumbing inside the head vanity. I think this is all original 1983 piping. The mold is probably newer, though.
AFTER: Inside the head vanity. All the sewer piping is GONE because we now have a lovely composting toilet.
- Hole which leads to path to the galley sink, under the port settee. Hot & cold feed lines to the head, leaving the head are the shower drain line (white), and the feed line from the v-berth water tank to the galley sink area. Also passing through here: v-berth tank level sensing wires, USB charging port wires, and wires to eventually power our (future) watermaker.
- Air ducts for our heater - Webasto diesel forced air.
- Exhaust air lines for the composting toilet, which goes outside through a clam-shell vent on the cabin side.
- Drain line for sink in head
- Shower drain pump. Pumped aft and into torpedo tubes in stern.
- USB & cigarette lighter port wiring for ports in cabin.
- Through hull valve, 3/4", for sink drain
- Through hull valve, 1-1/4", for removed toilet. Plugged with bronze plug.
- Through hull valve, 3/4", feed water for removed toilet. Plugged with bronze plug, but we plan to use this as feed water for future watermaker.
- Floor plate I made out of King Starboard to make a floor by the cabinet hatch
- New access hatch
Attachments
Last edited:
