Water System Problems

[Dockhead]

Just yesterday I got back to my boat in Denmark after a grueling business trip to SE Asia. Because Russian airspace is closed, getting to and from Northern Europe to SE Asia has become much harder, longer, and more expensive. Singapore used to be a reasonable nonstop flight from Helsinki or Copenhagen; now it's a rather grueling trip with a stop in Doha, Dubais, or Istanbul, and overnight in both directions instead of just in the Eastbound direction.

Yesterday I arrived from Singapore via Istanbul, an exhausting flight via two completely full planes, and I in economy class because I'm working on a startup without the budget for normal flying. My friends, via WhatsApp (which works for free on Turkish Air flights via satellite), are asking me periodically -- you must be dying to go to sleep. Yeah, after three overnight flights in 8 days, 5 cities -- I could use a long sleep. But even much more, I want a shower.

I'm driving the rental car after finally arriving, and I'm thinking -- I am dying for a long, hot shower.

I arrive at the boat, get the Eberspacher going, warm up my heads compartment with additional electrical heat, and get in the shower. Bliss! I think. I wet myself down with the luxurious hot water, then soap myself up all over, turn on the tap to rinse off, and -- nothing.

I can't repeat here what I said at the moment -- against the forum rules.

So I wipe the soap off as best as I can with a towel, and dive into the bilge to work on the water system. Just what I wanted to be doing after 20 hours of flying, and no sleep!

I remove and disassemble the pump, which is only two years old, a Johnson. It takes a bit of time, working methodically, but I find the problem -- failed microswitch in the pressure switch. A tiny cheap part weighing about 5 grams -- totally unsuitable for this applicable IMHO.

Remember my goal is to get water back on TODAY, so setting this aside and ordering a new part is not a plan. So then I disassemble the previous pump, and I think I find the problem -- a corroded connection. I fix this, put it all back together, and reinstall it. Not easy single handed, and I have to change the mounting position and rerun some of the lines because this pump is taller.

I switch it on and, Eureka! Works! So I finally get that blissful shower, and I'm somewhat proud of myself for being able to solve this whilst at the point of exhaustion and sleeplessness. But then another problem from the previous pump appears -- it produces overpressure and occasionally pops off the pressure relief valve on the calorifier.

Argh. I'm sick of these problems. I lost two precious days of my summer cruise year before last screwing around with the water system, and I'll be damned if I do that again this year. I need to fix this once and for all.

So here's where I need advice from you guys. I am thinking the following:

1. Give up on the built in pressure switches, even if the original one on my boat served faithfully for 15 years without a problem. I guess they just don't make them like they used to.

2. Therefore go to an external pressure switch, something adjustable, a quality one, and with a gauge. This will require a good bit of replumbing and reconfiguring to the water system space, but I don't see an alternative.

3. Add a non-return valve between pump and switch to eliminate dripback and subsequent unnecessary running of the pump.

I've already got the new accumulator tank, installed year before last when I was fixing the system before.

What do you guys think? Anything to add, subtract, or change? Or should I just replace the more robust looking pressure switch on the Jabsco pump? Or cut a loop out of the spring to reduce the pressure cutoff?

And here's some advice -- don't use Johnson water pressure pumps with the original pressure switches. They are utter carp.

[sailorboy1]

I think you should step back and relax awhile before engineering a complex system to replace a simple for little gain..

[Dockhead]

Originally Posted by sailorboy1

I think you should step back and relax awhile before engineering a complex system to replace a simple for little gain..

Thanks, but I got a good night's sleep last night! Actually some advantage in not being allowed to go right to bed in the day time after jet lag.


I am open to leaving the system simple. I am actually specifically soliciting advice on this. But I've had problems with two different pumps and I really want to end them once and for all.


A third way to do this would be to simply buy yet another new pump, this one not a Johnson, then buy spare pressure switches for the other two. This will require no reconfiguring of the water system space or plumbing.

[Pete7]

Originally Posted by Dockhead

A third way to do this would be to simply buy yet another new pump, this one not a Johnson, then buy spare pressure switches for the other two. This will require no reconfiguring of the water system space or plumbing.

Buy two and ditch the old ones. our Jabsco one lasts a decade, goes noisy and then leaks internally and externally. Probably equivalent amount of use as you each year.

Same with our manual Jabsco heads pump, life is too short to be faffing around with old worn out pumps.

[Sparx]

My suggestion would be to step back and think about how to quickly swap out components. You can choose for yourself wether a pump with internal switch or a pump with separate switch better meets your needs. Then by careful choice of how these components are mounted, wired, and plumbed end up with a system that is easy to swap in a spare.

Consider for example a water pump with direct mounted inlet screens and internal pressure switch (will have a single set of wires serving both pump and switch).This installed on a mounting pad with flexible tubing on the inlet and outlet side. The wiring lands at a nearby terminal strip. Then hold a complete spare ready to go. The result would be a very quick swap out. The spare can be diagnosed offline if need be.

As for the pump cycling my preference would be to not install a non return valve as that is just another component to fail. On my boat the pump cycling has been due to a dripping faucet more than back flow.

On my boat the Marco water pumps with internal pressure switches are now 6 years old with no problems at all (not a full time live aboard). The inlet screens need to be cleaned seasonally, but that has been it.

[sailorboy1]

Originally Posted by Dockhead

I am open to leaving the system simple. I am actually specifically soliciting advice on this. But I've had problems with two different pumps and I really want to end them once and for all.

I of course understand this. My current water pump, a standard Jabsco, is 6 years old and is working fine after with 2 people on the boat full time.

I have had problems with it cycling too much due to the check valves back flowing. Last time was over 3 years ago and I ordered a new pump, but before it arrived the problem went away. I of course will now never have a problem because I have a spare on the boat that has not been out of the box.

[gs41escapade]

I would buy another pump and keep things simple. You can make things more complicated, and still something fails, and now you have more complexity.

You mentioned corrosion on the old pump. Was that also the problem for the microswitch on the first pump? I would think about what you can do to better protect against corrosion. If the microswitch is also easy to switch out, I'd buy several as spares.

[HopCar]

The two most common problems I’ve seen on water system pumps are bad switches and bad valves. Pick a good pump and buy two of them. Buy a spare switch and valve set. Install the new pump in a way that makes it easy to exchange. When the pump dies, just swap it for the new one and repair the first one when you have time.

[Bowdrie]

Originally Posted by Dockhead

1. Give up on the built in pressure switches,
2. Therefore go to an external pressure switch, something adjustable, a quality one, and with a gauge.
3. Add a non-return valve between pump and switch to eliminate dripback and subsequent unnecessary running of the pump.
I've already got the new accumulator tank, installed year before last when I was fixing the system before.

1, Yes, give up on the built in switches.
2, Yes, you can get a Square D switch at any hardware/big box store. The comparable switch made by Furnas is only a few bucks more on Ebay and is a much better unit with more robust internals and smoother operation. A Furnas switch should easily give 20+ years of service.
3, Non-return/check valves are mixed blessing, they add flow restriction that the pimp has to overcome, but can be ok, it's not an either/or.
Using an external switch will allow you to tailor the pressures of cut-in/cut-out and with a balanced air charge in the accumulator tank good operation is secured.
A fitting on top of the accumulator allowing an air hose to a remote Tee fitting that accommodates a Schrader and pressure gage in a convenient location is absolutely the cats-meow.
I stay away from pumps made by Johnson. Jabsco, and Shurflo. The Flojets are superior, but there are others that have good reports.
Don't depend on the tiny inlet screens that are built into the pumps, use a separate bigger inlet screen where you can visually observe the contents and simply unscrew the housing to clean, like the little Par/Jabsco unit.

[wrwakefield]

Hi DH,

Since you are heading toward a new pump eventually, I would suggest you also consider changing to quality variable speed fresh water pumps.

This was my first boat with a variable speed potable water pump. No accumulator tank. No pump noise. Just steady pressure at any flow rate. A marvelous world of difference to the full on/off pumps we are all used to [be we still use for raw water wash down pumps.]

I have 2 variable speed plumbed in parallel [as hot back-up to each other - not simultaneous use; no pressure tank needed] and I switch between them every year [to wear them evenly since they last so long they will be (are now) obsolete when they start to fail…]

The first was installed in 2005 and is still going strong; the 2nd in 2016 as a hot back-up. But my pump models are obsolete now.

Looking ahead, for a spare and ultimate replacement my research led me to the Marco brand of bronze gear pumps. I haven’t used one yet, but know several other cruisers who do, and have no issues to report over several years of use. These are my current choice for replacing my current pumps when the time comes.

Bottom line: variable speed potable water pumps were a game changer for us. Now to stay on top of replacement pumps as systems age…

Other cruising friends with larger boats [90+ft] who charter often prefer the Groco Paragon line of water pumps.

FWIW

Cheers, Bill

[rslifkin]

Most pumps have crappy pressure switches that don't hold up and either fail to power the pump or they start sticking on. Either use an external one, or add a relay so the internal switch only has to carry the relay coil current and not the full load of the pump motor. That generally makes them much more reliable, as the tiny contacts are no longer subject to the same abuse.

[Bowdrie]

Nowhere on the Marco site could I find anything about their water pumps being able to self-prime, (did I miss it?).
So, must they operate in a flooded situation, as in being mounted below the water level in the tank?
If so, that is a mounting deficiency that would rule out easy use in many boats.
The little built-in pressure switches?
Even if they lasted forever, you're still stuck with the cut-in/cut-out pressures the company gives you, which are seldom optimum.
The myriad numbers of boats with all kinds of different hose sizes, fixtures, lengths of runs, and with or without an accumulator tank, (or what size it is,) all combine to make an externally adjustable switch a no-brainer.

[rslifkin]

Originally Posted by Bowdrie

The little built-in pressure switches?
Even if they lasted forever, you're still stuck with the cut-in/cut-out pressures the company gives you, which are seldom optimum.
The myriad numbers of boats with all kinds of different hose sizes, fixtures, lengths of runs, and with or without an accumulator tank, (or what size it is,) all combine to make an externally adjustable switch a no-brainer.

Some pumps have a little adjustment screw on the built in pressure switch. I know my Jabsco water pump does. You can't adjust the difference between the cut in and cut out points, but you can adjust the whole range up or down.

[Sparx]

Originally Posted by Bowdrie

Nowhere on the Marco site could I find anything about their water pumps being able to self-prime, (did I miss it?).
So, must they operate in a flooded situation, as in being mounted below the water level in the tank?
If so, that is a mounting deficiency that would rule out easy use in many boats.

I have a Marco pump that routinely self primes making about a 2.5 foot lift. I don’t know the limit for self priming.

….If that helps

[wrwakefield]

Originally Posted by Bowdrie

Nowhere on the Marco site could I find anything about their water pumps being able to self-prime, (did I miss it?).
So, must they operate in a flooded situation, as in being mounted below the water level in the tank?
If so, that is a mounting deficiency that would rule out easy use in many boats.
The little built-in pressure switches?
Even if they lasted forever, you're still stuck with the cut-in/cut-out pressures the company gives you, which are seldom optimum.
The myriad numbers of boats with all kinds of different hose sizes, fixtures, lengths of runs, and with or without an accumulator tank, (or what size it is,) all combine to make an externally adjustable switch a no-brainer.

I see what you mean. The manufacturer’s site I linked needs work. [I was unsuccessful downloading manuals, seeing additional product images, or anything else.]

Since self-priming is one of my requirements, I know I previously vetted that feature on the Marco water pump line.

Looking again, I did find general info listed with a few randomly selected pumps on the Marco site:

Self-priming electric pumps with PTFE [or bronze] helical gears. Pressure switch, check valve to be used as [variable speed] automatic pumps for water pressure systems on boats, mobile homes etc. Nickel plated brass body, stainless steel shaft.

Here is another example listing 4.9 ft self priming head for a representative potable water pump at Fisheries Supply.

I found a manual for the above example Marco Pump.

Marco makes pumps for many purposes [e.g., fuel/oil transfer, water- potable and washdown, bilge, etc.] I believe all are self priming, but that needs to be confirmed on a per model basis.

In case this helps.

Cheers, Bill