Hunter used 1/2 inch Zurn (Quest) Pex Quicktite brand polybutylene grey plastic hose for the fresh water system on our 1991 P42. It has worked well for us over the years and was trouble free. It is also very reliable when installed correctly. It is my understanding that Hunter uses a different product on newer model boats.

It is my estimation that the fresh water pump located inside the port settee draws water from either the forward 65 gallon water tank located beneath the forward cabin berth or the 85 gallon tank beneath the port settee, or both through the use of a valve for each situated next to the pump. Each hose from the tank is first connected to a screen type filter in order to contain any debris that might harm the pump components.

The pump feeds water to the hot water tank also located inside the port settee and the cold water supply. Tee fittings distribute H/C water aft to connections for the clothes washer/dryer combo only and forward to the rest of the boat. Routing of the H/C hoses enter a limber hole beneath the hot water tank and cross to the starboard side through an athwart stringer to the starboard settee. Tee fittings distribute water forward to the forward cabin sink and shower and aft to the galley sink.

More tee fittings distribute water through hoses inside a starboard parallel stringer from the galley through the underside of the engine room to a limber hole next to the sit tub. More tee fittings beneath the sit tub distribute hoses to the aft sink, then more tee fittings to the transom shower. If you use a bright flashlight shining across the engine room, there is a small square hatch next to the battery bank steel frame starboard side where you can see some of the sit tub plumbing. The only way to access this plumbing is by removing the lower 8D battery case.

Using one hand (only room for one), it took three hours to perform a recent repair to one hot water tee fitting. What happened was that whoever put the fitting together did so incorrectly, which caused water pressure to eventually blow the tubing out of the fitting. Each fitting is supposed to have a nut, a SS retainer ring and a pressure cone. The cone seals, the ring locks the hose and the nut secures the fitting. In my case there was no retainer ring on this fitting.

Normally, I tighten each fitting by hand until it squeaks, then another quarter turn. You want to avoid over tightening plastic fittings. In the case of the forward water tank connection, which is a shut off valve installed on a metal pipe, I use plumbers tape to obtain a water tight seal since there is no retainer or cone.