Fresh Water system Pressure 43 Post

Want to check what pressure others fresh water system is. Ours currently has a 40 psi pump, but everyone is out of stock on the 40 psi. Wondering if I could use a 60 psi which is available.

Thanks - Greg

Did an experiment. Hooked the boat to our dock water on the dock water inlet. Put a pressure gauge on the cockpit wash-down outlet connected to the fresh water system. My gauge apparently is dying from old age so results are interesting but not accurate levels. When the internal fresh water system pump shuts off the gauge at the pump reads 40 psi. My gauge on the cockpit outlet only read 10 psi. When I put the stand alone gauge on my dock water directly it reads 60 psi. From prior tests (when I had a water powered boat lift) our dock water usually reads 90-100 psi. When I turned our dock water on to the boat the gauge on the cockpit washdown also read 60 psi, which I believe to be 90+ psi in realilty. It appears either our boat does not have a dock water inlet pressure regulator (although I thought all Posts did) or the regulator is failed or set very high.

That said, the system does not leak anywhere I could tell in the couple minutes at 90+ psi. It has been on Baltimore city water for several days with no apparent trouble, which normally should be about 75 psi.

Still uncertain about installing a 60 psi pump, but seems to indicate system can handle that and more.

Ordered a new gauge to repeat the test with hopefully accurate values next week.

The manufacturer carefully notes that adjusting the pressure (when they tell you where the adjuster is) violates the warrenty, although it appears the only difference in the models is the setting of the pressure switch. Others have done that going both down and up. The other side effect of the higher pressure is the 60 psi pump is listed in different places as needing, depending on the source, either a 20 or 25A breaker.

I may have found a 40 psi pump but won't know if really in stock till I can call and confirm next week, the ones listed in stock that I have called so far do not have any even though their online order systems say they do.

The current accumulator does well at holding pressure and letting the pump switch out and back in during steady water use. We only have the galley, one head sink and shower, and now the fresh water flush head so not a terribly high volume use. The new pumps are all rated at 4 GPM free flow vs the 3.5 GPM rating of the current pump so should give a little more head room.

Copper with short lengths to the pump of reinforced clear water hose (listed rating 250 psi). Not as concerned about what I know as much as if there is something I didn't account for. I need to check what pressure the accumulator is set at, half the label is gone so no way to tell what it is rated for but it is steel.

Open item is what size breaker is on that line. Most of the 12V on the boat has 20A breakers, but to check label on individual breaker I have to remove the feed buss bar.

Our current comes on at 20 off at 40. The 60 psi pump would come on at 40 off at 60.

Thanks. That is what I'm leaning to put in.

Was fine with non flow restrictor aerator.

New pump installed (40-60 psi cycle). Cleaned up the PO wiring (wire nuts!!!) and mounting. It does have a much nicer flow. The PO had the accumulator set at under 5 psi (minimum my gauge reads to), so I charged it to 3-5 psi below cut-in based on the Jabsco accumlator tank manufacturer reference (https://www.jabscoshop.com/files/Accumulator and Expansion Tank Instructions ZPWL4 doc595.pdf).

Did pump change before accumulator. Noticed big improvement with pump (the old one probably has been dying for a while), didn't notice much with accumulator precharge.

Agree. I only looked at flow. Didn't look at cycling time.

Can't comment on temp as the water heater hasn't been on. Water from the tanks is probably 85-90. Will have the heater on this week as going on a 6 day trip.

No noticible change in flow before the pump kicks in. With the old lower pressure/probably dying pump and the PO not charging the accumulator there was a noticible drop. There was enough label to read the p/n (1ET2G12F) so could verify the accumulator is 2 gallons. It's now pre-charged to 35 psi, 5 psi below the pump switch-on pressure.

Here is how it is plumbed (picutre is old pump).