Water accumulator tanks -- pro's and con's

LaRea

I recently replaced my fresh water pump (galley pump, domestic water pump, whatever you want to call it) and realized that I've probably spent $1000 replacing water pumps over the last 17 years.  They never last more than 2-3 years.  My theory is that the constant cycling on-off-on-off eventually kills them, which leads to my question: If I install a water accumulator tank, will it make my water pump last longer?

An accumulator tank is a small water tank pressurized by an air bladder.  When you open a faucet, water flows from the tank instead of the pump.  The pump runs only when the accumulator tank gets low, and then it runs continuously until the tank is full.  No more constant cycling of the pump.

Does anybody have practical experience, positive or negative, with these devices?  Are they reliable?  Any problems with maintenance, winterizing or dewinterizing?  Is it worth the cost and complexity?

Handymans342

I had one in my RV for many years. Never replaced a pump or tank. Once you bleed off all the water pressure for the winter, the tank is dry. 

Dream_Inn

Sounds like too much hassle, but that might just be me.  I'm with Handy, I use nothing but my fresh water pump to keep my tank water clean and never a problem.  Only thing I don't like is hearing my pump cycle all the time.  I've been doing this for 15+ years with 3 different boats.  I'm really curious why you'd only be getting a couple years out of a pump.  Do you turn it off when you are away from the boat?  the accumulator tank sounds nice in respect to not hearing the cycling all the time, but it is just one more thing that would need maintenance.

LaRea

We're only pumping 5-10 gallons a week, so it's not like we're over-using the pump.  However, I use a 4 GPM pump instead of the usual 3 GPM because I like having the higher flow rate for showers.  The tradeoff is even more cycling, which is probably why they don't last as long for me.   

An alternate solution might be one of the new variable-speed pumps, but they cost over $300.  An accumulator tank is only $80.  

For a big boat with an extensive plumbing system, it's an easy choice to install a 2-gal or 5-gal accumulator tank.  For an express cruiser with only three sinks, a toilet and a shower, the decision isn't so clear-cut.  

JC290

never looked into this,but i would assume you could find an adjustable pressure switch where it had a bigger range would help with cycle time. the down fall would be increased pressure on house lines

Dream_Inn

I'm betting the 4GPM is a different type of pump or maybe is not made to cycle as much?  That seems to be the only difference.  I too would love to have a bit more pressure, especially at a couple sinks (our aft sink and head shower seem to have good pressure, must be the pressure heads).

Handymans342

Guess its more of a personal preference then. 

Handymans342

You would think they would make a more quiet pump like the AC pump. 

LaRea

The maximum water pressure is determined by the air pressure in the bladder, which can be adjusted with a normal bicycle air pump.  They recommend 40-75 PSI.  The minimum pressure can also be adjusted to make sure the pump turns on at the appropriate time (around 10 PSI).

Jabsco claims that their tank provides:
• Smoother and More Even Flow
• Quieter Water System
• Better Temperature Control
• Longer Pump Life
• Lower Battery Drain

Dream_Inn

 you both make good points.  Handy, I agree that the pump should be much quieter.  Heck, that AC pump puts a lot more water out there than the fresh water.

LaRea, smoother and more even flow would make it worth while.  & the temperature control in the shower would be nice!  Ours jumps around depending on pressure. Once you get it all figured out, let me know! 

Handymans342

Check Campingworld.com

Dream_Inn

ok, just checked & looks like it's on sale with good ratings.  Hmmmm....

http://www.campingworld.com/shopping/item/shurflo-accumulator-tank/2290

for that price it may just be worth trying!

MarkB

I'm going  into my 4th season with my galley pump. Still looks and operates like brand new. 

LaRea

Hmm.  
ShurFlo, only $45.  
Jabsco, bigger capacity (32 ounces vs. 24), and it comes with the same quick-disconnect fittings as my pump, but it costs $75.  

Handymans342

Go for it LaRea, your rich. 

LaRea

Rich?  Try boat-poor!  But I might have an easier time fitting the smaller ShurFlo into my engine room.

Handymans342

We are all boat poor but we keep doing it. The tank will help, trust me. 

Dream_Inn

I like the correct fittings.  You could of course get the smaller jabsco for $54 with the correct fittings.

Dream_Inn

Actually LaRea, I've found the large now for under $60.  Man, I think I'm talking myself into this more than you.  I hate the loud chattering of the pump!

Handymans342

Nice to have a quiet pump while anchored up in Tikis old hole. 

LaRea

I hereby elect Dream_Inn to be the test boat!

craigswardmtb

Pretty funny to read this from the beginning. DI talked himself right into a new project...  I seem to do that every time I sit in my engine room for more than 10 minutes. My wife now puts the timer on every time I'm down there. I tell her she has Pinterest, and I have my engine room. 

craigswardmtb

After I installed a new pump the noise diminished and I see no reason for the accumulator tank. It seems like a step backwards to me with it being such a simple small system, so long as the new pump lasts. Especially with regards to space. But if you have space and it'll address your issues than you should go for it. 

Dream_Inn

 Craig, I agree that a new pump would address noise, heck maybe adding some thick rubber to the mounting would help.  But, the accumulator would also fix the turning off and on frequently (which in turn changes the water temp in the shower). 

& you are right.  I've talked myself right into this one! & I love sitting in the engine room.  It's even better having another buddy sit down there and we have a cold one and discuss what can be improved!

Handymans342

Cant beat sitting on a diesel though

LaRea

I'm not seeing any drawbacks, other than initial cost.  

@craigswardmtb -- in another thread, you mentioned that some SeaRay owners are moving away from accumulator tanks.  Any idea why?

Regarding pump noise, I doubt it would be possible to make any real difference by changing how the pump is mounted.  The stock rubber bushings help a little, but the pump vibrates at very low frequencies.  That means you'd need a much larger, much softer mount to make a difference.  Unfortunately, soft mounts would allow the pump to shake too much when you hit waves or wakes, and I think you'd eventually get leaks or broken fittings.

Handymans342

What we need are rubber vibration pipe couplings so the vibration does not travel from the pump and into the pipes. 

LaRea

Well, I broke down and got the Jabsco 1-liter accumulator tank.  

Installation was dead simple.  It took all of 45 minutes including cleanup.  (Well, 90 minutes if you include my trip to the hardware store for hose fittings.)  I installed it on the down-pipe coming out of my water pump.  The tank is horizontal, attached to the firewall with two screws.  I doubt it will ever get in the way of any maintenance chore, but if it does, I can remove it in about two minutes.  

First reaction: It works as advertised.  If I open the faucet  a little, it's silent, then the pump runs for 2-3 seconds.  No more annoying BRAP-BRAP-BRAP.  

I will say that the pump cycle time, although MUCH improved, is still shorter than I expected.  Maybe I need to adjust the pressure in the air bladder, or maybe it's just because I have the high-flow 4 GPM pump.  But for anybody considering one of these, I'd recommend getting the largest tank that will fit in your engine room and budget.  

I'll reserve final judgment until I wait 2-3 years and see if it made my water pump last longer. 

Handymans342

Yes, larger tank is best

Dream_Inn

I took a look around my water pump this weekend to see where I would mount and the type of connections needed.  I'm thinking the connection would be a pain because I have that rigid water line and the tank would not mount on the same wall as the pump.  LaRea, if you can get a picture of your install, maybe that would give me some ideas as well!

LaRea

Your water line is the blue 1/2" PEX, right?  It's easy to cut.  I used a cable cutter, but you could do it with a razor knife.  

The fitting you need is 1/2" barb to 1/2" female threaded.  I couldn't find one at my local store, so I got a 1/2" barb to 1/2" FIP.  The FIP is actually a tapered pipe thread, but it worked because the male fitting is plastic.  (It was a tight fit.)  

For the hose connection, heat the end of the hose with a heat gun or hair dryer to soften it up, and the barb will slide right in.  Add a hose clamp and you're good to go.  

The tank just needs to go somewhere before the Tee fitting that leads to the water heater.  In the photo, you can see my water pump at the top, and the tank about 6" below.

Here's a close-up of the hose fitting.