Freshwater pumps w/o Accumulator tanks

[jlubimir]

Does anyone have experience with the Flowjet, Shureflo or Jabsco pumps that allow you to eliminate the accumulator tank? Any poss. downside?

thanks.

John

[MJWEENZ]

Our last boat, a Carver 36, had the Shureflo pump with no accumulator. The system worked OK but "pulsed" when on. I toyed with adding an accumulator but lack of space was an issue. I'm sure it would have worked better with one but was servicable without.

Mike

[Randal Johnson]

John
My boat was built with a Jabsco pump that was promoted as not needing an expansion/accumulator tank so the builder didn't install one. The problem was the system has a hotwater heater in it. The pressure relief valve would discharge occasionally and I traced it to the fact that the heated water had no place to expand to. I installed a tank and now have no problem.
Randal

[Daniel du Toit]

Generaly you do not need a accumulator tank for your system, depending which pump you use. However, it does ,most of the time, eliminates that pulsating effect. You will also find that your flow will be better when you open your tap just a little bit. Personally, if I have the space, I will install one.

[scotte]

We added a small accumulator tank - I think the capacity is only around 16 ounces or so, but it completely solved our pump pulsing issues. It doesn't take much volume to fix this, and give a small tank a try first!

[Daniel du Toit]

I'm not to sure, just check with your local supplier, some pumps have a "set screw" that you can ajust to stop the pulsing effect...?

[bstreep]

Have a Sureflow - what a great upgrade.

[James S]

Originally Posted by Randal Johnson

John
My boat was built with a Jabsco pump that was promoted as not needing an expansion/accumulator tank so the builder didn't install one. The problem was the system has a hotwater heater in it. The pressure relief valve would discharge occasionally and I traced it to the fact that the heated water had no place to expand to. I installed a tank and now have no problem.
Randal

I'm confused...Jabsco recommends putting a check valve at the supply into the water heater.
They also suggest (in the instructions for there expensive accumulator tank) that it be installed down stream of the pump, cold water side.
When the water heater heats up, I don’t see it expanding back into the cold side because of the check valve, it would seem the accumulator should go in the hot side...is that where you put it?
Is the high temp no concern to damage the bladder?
Thanks.

[Christian Van H]

Just so we're talking apples to apples here, are these the new pumps with the electronic sensors instead of switches? Some have 5 chambers, some have 4...

[James S]

Its the Jabsco VSD 17 has 4 little diaphragms and I'm pretty sure it got an electronic sensor.
Its run speed varies with use.
If I barely open the tap, it runs very slow....if I fully open a couple, it halls ass.

[Christian Van H]

Originally Posted by James S

Its the Jabsco VSD 17

Hey James! Thats the same model I'm looking at. Fully electronic sensor. Any pulsing apparent? Any need for an accumulator? It's probably the VSD 14 or 17 for me. Hows the output for showering? Too much?

[James S]

Hey Chris
I haven’t showered yet with it, but it moves plenty of water.

I went 1/2" all the way and have no lack of volume or pressure.

No pulsing what so ever.

I will mention that its not that quiet...it’s ok for me, I like to know its running.

My pump is in the bilge and I haven’t yet run it with the board all installed, so I imagine it will get a bit quieter...also seems to produce a fair amount of vibration.

But what about this concern of the expanding hot water...my tank is not yet energized or plumbed to the engine so I have not tested it, but have read what Randal said and am a bit concerned?

One other note….when it runs out of water it keeps running but has a very different sound, so it obvious something has changed.

Also it had no problem pulling the water up a couple feet from the near empty tanks with no prime what so ever.

[Christian Van H]

Thanks James! As far as noise goes, IMHO never install a freshwater pump you cant hear. On a charter out of the Florida Keys, the stern shower nozzle blew out its seal right after my son showered. Unbeknown to me, we vented 80% of our fresh water before I found the leak. Thank God I was next to shower. Couldn't hear the pump run at all. So now we're approaching the Dry Tortugas for a several day stay, four people onboard and 15 gallons of water (besides bottled drinking water) left to share. Can you say rationing...

Oh, and on my boat the fresh water manifold will NEVER have all 3 tanks turned on at once. I'll end up with at least 50 gal. that way...

[Captain Bill]

I have a VSD 17 and have had no pulsing issues. Shower pressure is just fine. It's pretty quiet at low flow rates but despite the advertising to the contrary at high flow rates it gets pretty noisy. It's located under one of the bunks in the rear cabin and will really make someone jump when someone turns on a faucet.

[s/v Jedi]

We have the Jabsco's (bigger model I think but with sensor) and they are just lovely. No pulsing and no breaking down. Before that, we had the same thing from Shurflo with many problems (these extreme things). They have too much pressure (65 psi) which can't be changed, started leaking etc.

We have no checkvalve into the waterheater. It's purpose would be to protect the plumber working on a mixing-faucet on the boat. (shut down pump, disconnect cold but get back-run hot from heater).

A nice thing we did: you probably end up buying a spare pump. If you have anything spare, they tell you to get a spare waterpump first. We decided to install it parallel to the normal one, with it's own breaker. This gives you: more flow when both are on like when flushing/emptying tanks; you know spare is working; flip a switch when pump brakes and do repair later; periodically switch to other pump so both get used and last longer.

cheers,
Nick.