Domestic Water aka Fresh Water System

The fresh water system is critical to survival of the crew. The fresh water system may be over designed but it is designed to have redundancy that will provide a sufficient amount of fresh water as well as minimal inconvenience if some components fail.

Many of the components of the fresh water system such as the water maker and fresh water pumps are electrical components and therefore rely on a functioning electrical system. To avoid losing access to fresh water in the case of a major electrical failure, such as a lightning strike, a manual foot pump operated fresh water spigot will be included in the galley.

Watermaker and tankage

At some point a watermaker will be installed. The Watermaker aka Desalination web page covers the selection of a watermaker and installation.

The fresh water side of the watermaker will lead to the two water tanks on the port and starboard side. Each is 52 gallons and is under the settee. Each tank has a water fill deck plate and a vent hose and each tank has a vertical length of clear plastic tubing to provide a means of roughly measuring remaining water supply in the tanks.

Each tank has a ¾" ball valve mounted on the aft corner of the tank nearest the centerline of the boat. A ¾" hose is connected to each of these ball valves. These two hoses are connected to an assembly that has a total of five connections. There is one for each tank and one for each of the two pumps for the pressurized water systems. The fifth connection is at the lowest point and has a ball valve and short length of hose. This hose is intended either to drain the system or to serve as an intake for antifreeze (the non-toxic propylene glycol pink stuff). The assembly is suspended above the bilge toward the back of the keel sump. This is central and allows easy drainage. The assembly is made of tees and short pipe sections and elbows plus the one ball valve and five NPT to ¾" barb fittings for the hoses.

Separate pressurized water systems

There are two separate pressurized water systems. On the port side is the galley fresh water system, serving only the galley sink but with a line running forward. On the starboard side is the forward cabin fresh water system serving the vanity and shower with on additional line. These two additional lines run to ball valves and a tee. The ball valves determine which (if any, but normally not both) of the fresh water systems provides flush water to the head. It makes litte difference which is used. However if one fresh water pump gives out the two systems can be connected at this tee by openning both ball valves and the working fresh water pump can supply both systems until the failed pump is fixed or replaced.

Galley pump, expansion tank and water heater

The pump for the galley fresh water system is beneath the port settee, just aft of the port side fresh water tank. The expansion tank and water heater are behind the settee back rest, as far aft as the can be placed and high enough so that there is plenty of depth between the framing and the hull to accomodate each without touching the hull and with ample clearance to allow for hull flex. A short mounting stub will be glassed in on either side, the hull and the cabinetry. A slightly undersized shelf will be bolted to the mounts on each side, with large washers and oversized holes to allow the shelf to float while the hull flexes. The expansion tank will be under the water heater since the expansion tank needs less depth.

The hoses on the fresh water presurized side (as opposed to the tank side of the pump) will be ½" almost clear colored hose. The cold water side will use blue hose and the hot water side will use red hose.

A vertical hose will be connected to the water heater cold water side and lead to a tee mounted on the expansion tank, then another section of vertical hose and then a tee connecting to the pump hose. Below this tee will be another hose leading to the lowest point in the galley water system where there will be two more tees, a ball valve, and a section of hose leading to the bilge. This lowest point is used to drain the system. Off the tees will be the galley sink cold water and the hose leading forward toward the head where it will have a ball valve. Plumbing for the head fresh water flush is described in the Fresh water for the head section.

A vertical hose will be connected to the water heater hot water side but in this case have only one tee for the galley sink hot water and still have a ball valve and hose for drainage of the system.

The hoses to the galley sink and the hose going forward need to be secured so that they slope gradually up with no dips to collect water and prevent the system from fully draining.

Forward cabin pump, expansion tank and water heater

The installation of the pump, expansion tank and water heater for the forward cabin is nearly identical except on the starboard side. There is one less tee on the cold water side since the hose running to the head will be on a tee with the hose to the cold side of the vanity sink and with a second tee on the cold side of the shower. The hot water side will have a hose running forward to a tee below the galley sink and then continue to the shower.

Both the cold and hot water hoses running to tees under the galley sink must gradually slope up to allow drainage, but not rise too high as to allow the shower plumbing to drain and head fresh water plumbing on the cold side to drain. These hoses will be run forward to the large bulkhead about 16" forward of the cabinetry for the v-berth, then athwartship along that bulkhead, then aft slightly to the shower for the hot water and to a tee and the shower and ball valve and tee for the head fresh water flush. Plumbing for the head fresh water flush is described in the Fresh water for the head section.

Fresh water for the head

One hose from each of the fresh water systems will lead forward to two ball valves, one for each system, located on the plywood bulkhead forward of the shower enclosure and on the outside of the shower enclosure. Hoses from each ball valve will go to opposite sides of a tee. The hose going up from the tee will bend 90° to horizontal and go to the solenoind assembly. On the other side of the solenoid assembly a hose will go to a tee with one side of the tee going to the salt water pump and the other side going down to a second tee. At the second tee the middle branch will go to the head and the lower branch continuing down to a ball valve and then into the bilge.

Draining the fresh water system

Some of the fresh water system components don't like to be left with antifreeze in them. The best way to winterize the fresh water system is to pump through antifreeze and then drain the system. If there is any small amount of fluid left the fluid will be antifreeze and not crack anything due to expansion while freezing.

There is an assembly connecting the tanks to the pumps that is located suspended over the aft part of the keel sump in the bilge. This is described in the Separate pressurized water systems section.

The hose from this assembly should be rinsed by making sure the bilge is empty, raising the hose slightly, and emptying both tanks with at least one bilge pump running (on auto). To empty the tanks keep their ball valves open and open the ball valve at this assembly. Then close the ball valve at each tank.

After tanks are emptied and their ball valves closed, the hose from this assembly can be placed in a bucket with antifreeze in it and the assembly ball valve still open. Each pump can be turned on and the shower plus each sink can be run until antifreeze comes out then shut off. The same applies to the head which can be flushed (literally) until antifreeze has filled the black water hoses. The gray water and black water systems can be emptied (but not into the bilge, obviously).

With the fresh water pumps shut off the pair of ball valves under each water heater can be openned to drain the antifreeze, also openning all faucets and both hot and cold gate valves for the shower (or whatever fancy valve is used). See the Galley pump, expansion tank and water heater section and the Forward cabin pump, expansion tank and water heater section. The ball valve for drainage near the head (see the Fresh water for the head section) should also be openned.

At this point the system should be drained and any fluid remaining will be antifreeze.

Potential failures and the role of redundancy

There are a lot of potential failures in the fresh water system. Most can be temporarily covered by redundancy but there are a small number of single points of failure (ie: no redudancy). The following list describes potential failures and remediation.

Total electrical system failure: A total electrical system failure at sea is a major hardship for many reasons. One problem that could threaten survival is access to fresh drinking water. An extra tee can be added to the tank hoses leading to a foot pump and spigot at the galley sink. If this isn't done the tank drain hose can be used.
Watermaker failure: If the watermaker fails on passage the up to 104 gallons of water in the tanks should provide plenty of water for one or two people to finish a crossing with water conservation. If the tanks are low, rain catchment may be needed.
Tank leak: The tanks are very heavy gauge stainless steel with solid weld, but could leak. If one tank leaks the other can be used. The boat can be heeled to empty the leaking tank into the other and then the ball valve on the leaking tank can be closed.
Tank hose leak: The hoses between the tanks and the pumps has no seacock to isolate it. Both tanks will have to be shut off and the leak fixed. If it is a hose barb leak the hose can be removed, an inch cut off and put back on the barb and clamps tightenned. Spare hose and hose clamps should be carried on board. If a new hose is needed, spare hose can be used.
Tank and pump joining assembly leak: Both tanks will have to be shut off. Most leaks can be fixed by backing off joint completely, applying new thread sealing tape, and tightenning. In some cases if the threads have been damaged (by prior overtightenning) and there are no spares onboard then the leak will have to be tolerated until new fittings can be purchased. Both tanks will have to be shut when water is not in use. This assembly is stainless steel and given how critical it is, the joints might be welded to prevent leaks.
pump failure: If one pump fails, then both ball valves near the head and shower can be opened, connecting the two water systems together. If a spare is onboard the pump can be replaced while underway.
expansion tank leak: If an expansion tank leaks it can be bypassed in the plumbing and the two water systems connected so that there is at least one expansion tank available.
water heater leak: If one water heater leaks the hot water can be looped back to the cold water and one of the systems will have no hot water until the hot water tank is fixed or replaced.
leak in the galley water system: If there is a leak in the galley water system that can't be fixed, water will have to be taken from the vanity faucet and brought to the galley until the leak is fixed.
leak in the forward cabin water system: If there is a leak in the forward cabin water system that can't be fixed, water will have to be taken from the galley faucet and brought to the vanity. Showers may have to be curtailed or use the bucket of water over the head method.
leak in the head flush water system: If the head flush water system has a leak that can't be fixed then the flush will have to use fresh water and the ball valves to both fresh water systems shut off. Since there is a vented loop water can't siphon to the leak. If the leak is minor, then a small amount salt water will leak only while filling the bowl. If the leak is too big to be tolerable the bucket method of filling the bowl will have to be used.

It is very important to carry spares. Some spares are inexpensive such as lengths of each size of hose and spare hose clamps. Some spares are moderately priced, such as pumps. Spare fitting should be onboard as well as plenty of spare o-rings if quick connect fittings are used. It maight help to carry some spare plumbing fittings and of course thread sealing tape or thread sealant for metal to metal fitting connections.