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Project Log:  Wednesday, May 20, 2015

During a routine check the day after running the engine, I discovered that the coolant level had dropped in both the expansion tank and, on further investigation, the engine's heat exchanger tank (which, being lower than the expansion tank, could not be opened routinely any more).  This was not surprising, given the overall volume of the related system, so I added more coolant to the expansion tank, ensuring it filled up the engine heat exchanger, after which I closed that cap and added more coolant till the expansion tank was close to full.  I didn't know how much coolant was actually supposed to be in the high coolant tank, so I stopped a little short of full lest it overflow during normal expansion (as per usual). 

However, this highlighted the fact that the expansion tank (and its compatriot on the opposite side servicing the heating system) did not have a means of draining neatly, as I'd not yet installed a drain hose on the cap.

With proper hose now on hand, I led a line from the expansion tank and down into the bilge, where it could expand harmlessly.  I repeated the process on the starboard side for the heating system (not yet commissioned).

         

         

In the "this should have been one of the easy jobs" file, allow me to present the fresh water pump.  In terms of systems commissioning, I figured this one would be straightforward:  put in some water, turn on the pump => water out the tap.  Alas, no.

The first part was easy and effective:  with a hose, I put some fresh water in one of the three new water tanks.  I chose the starboard saddle tank since it was closest to the water pump, which was located just above the tank on a shelf.

Next, I turned on the pump.  The pump worked, but would not pump any water.  Or, perhaps more specifically, it would not prime itself, seemingly.  With an advertised dry-prime of 10 feet, it didn't seem the length of hose before the pump should have been an issue.

The pump I'd chosen, and which I'd installed some time back while working on the systems side of things, was a normal water pressure pump (with built-in pressure switch) combined with an air tank that was purported to maintain smooth and even water flow at all volumes.  Reviewing the instructions, I found that the tank was supposed to be pressurized before use; unhelpfully, the instructions referred me to the label on the pump tank itself for more detail about this, since printing them in the instructions themselves obviously might have posed serious problems for the manufacturer.

Of course the air valve for the tank was against the hull, and in my ignorance at the time of installation I'd not accounted for this.  Perhaps I didn't think I needed the instructions to install something so straightforward, but that's my cross to bear and I own full responsibility for that.  Regardless, I needed to access the air valve to check and pressurize the tank now--at least that seemed like it might be the issue, given the printed information to pre-pressurize the tank.

The tank was nestled in its cozy space on a utility shelf above the starboard tankage space outboard of the engine room, and was generally well-accessible.  But after removing the screws securing it to the shelf, I found that various hoses and wiring led above the pump (apparently after the pump's installation) now limited how far I could lift up the pump, so I couldn't get it high enough to lift over the shelf fiddle before it.  Strike two for me.


To remove the pump, and access the air valve, I undid the wire bundle running along the fiddle, then cut out a section of the fiddle, allowing the tank to slide straight out.  Relatively easy and fairly non-destructive.  I'd left enough extra wire to pull out the assembly and turn it around, accessing the air valve and helpful labels on the tank and pump.

    

This called for 25 PSI in the tank, which I installed with an air hose.

Putting the pump back in place and reconnecting the intake line (which I'd had to remove in order to pull out the pump), I confidently turned the pump back on, sure that water would stream in immediately.  No:  the same problem.  I repeated this process a few times to be sure the tank had its pressure.

Puzzled (perhaps there are stronger words for my actual feelings, but that will do), I tried several interim fixes as they occurred to me, including trying to use the galley foot pump to prime the line (that wouldn't do it either), and I even blocked off temporarily the manual pump line, which by necessity was in the intake line upstream of the electric pump, to see if that was affecting the electric pump's ability to self-prime, but all to no avail.

By now, my artificially-shortened day was coming to a close, so I had to leave it there for now, unresolved.  My next effort would include pre-priming the supply lines with a hose, but for that I needed a garden hose adapter to connect into the various 1/2" water lines on board, and I didn't have one on hand.  Whether this would solve the issue or not remained to be seen, but seemed a logical option, if unnecessary (in a global sense) to my way of thinking.  Failing that, I planned to replace the pump with something else, but I did hope to avoid that option.

If I sound disgusted by this unforeseen challenge, it's because I was, and am, all the more so because I couldn't logically see why this pump couldn't pull water out of the tank.    Perhaps I was trying to apply logic where logic didn't apply, as I am wont to do.
 

Total Time Today:  3.25 Hours

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