Higher pressure water pump?

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Julian Elliott

My Jabsco 31750 fresh water pressure pump just gave up the ghost after 8 years of weak but reliable service.  The Jabsco distributor says this model is being phased out, and is recommending an upgraded model that is meant to replace it.
 
The dimensions and pressure specs are beefier.  I think I could deal with the dimensional differences, and like the idea of improvement in pressure, but want to make sure my system can handle it without additional regulation, accumulator tank, etc.  Anyone have experience in boosting pressure in the water lines and hot water tank?

New model is # 42755-0092.  Differences:

Flow rate:          5.0 gpm vs. 3.7 gpm
Constant pressure   40 psi vs. 25 ppm
Cut-off pressure:       60psi vs. 40 psi
Electrical:         Current wiring ok; claims lower power consumption

Thanks,

Julian

Ron Hill

#1
Julian : I'd stick with a pump that puts out about 25/30psi  - You don't need 40psi.  

Look at the Shurflow pumps in the marine catalogs (West M pg 494), decide on the pump and then get it ON-Line (much cheaper)!!

A thought
Ron, Apache #788

Stu Jackson

#2
Julian,

Don't buy it.

The C355 skippers have been having trouble with theirs:

Chris McDonnell s/v "Even Keel"    
11/11/13
Funny you should ask. I have a Jabsco 42755-0092 variable speed domestic water pump on my boat.  When you sent your email, my water pump was being inspected.  It has been erratic - sometimes pumping immediately when a tap is opened; other times having to cycle the breaker multiple times to get it going.  Tech thinks the pressure switch is the culprit.  He tapped on the stalled pump and it started immediately.  As the tech was leaving, our guru Gerry Douglas happened to be walking by and said hello.  He told me some pumps seem to be having an issue starting when on dock power.  Not sure that's my issue, as I have the problem on 12v only as well.  My boat is still under warranty, so Gerry is getting us a new pump (nice benefit of living next to the factory!)  Will let you know what the new pump looks like later this week, if same or different.  Chris

AND

Chris McDonnell s/v "Even Keel"    
Feb 7
As a follow up to my earlier post, I'm now on the 3rd water pump from the factory. The Jabsco Vflo pump mentioned by Jon Vez recently failed and was replaced with a Shurflo Aqua King II pump. Once installed, the pump cycled (pulsed?) constantly when a tap was opened, but a call to Shurflo requesting guidance to adjust the pressure switch did the trick.  Works smoothly now.  Hope this one does ends the pump saga.

********************************

I bought this one as a replacement:  Shurflo 3901-0216 3.0 GPM, 55psi  <$100 on sale a year or two ago.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

Julian Elliott

Well, that certainly does give me pause...

The owner of our local chandlery (who I respect) has has sold many of them, without substantive problems.  Feels the Jabsco is a reasonable price/quality tradeoff. Says Jabsco has worked hard on improving reliability. I'll circle back with him; he carries other brands and sells to the commercial fishing industry, who surely wouldn't put up with unreliable equipment.

Deep diving in Google brought up problems with the voltage and pressure sensing features of the fancy diagnostic system.  Sometimes technology just gets in the way.

I preferred the Jabsco unit because it would be simple to replace without moving plumbing, etc. 

Julian

Stu Jackson

Quote from: Julian Elliott on June 09, 2014, 11:07:59 PM

I preferred the Jabsco unit because it would be simple to replace without moving plumbing, etc. 



Julian,

"Plumbing" is really only simple hose.  A few straight barbs or els should do the trick.  I replaced all my hoses last year - now there's some real work!  :D
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

Julian Elliott

Stu,

Spoke this morning with the chandlery owner and got a much better understanding of water system design and pump technology.  He's very plugged in to tech advances among pump mfgrs, and is quite aware of issues with the Jabsco diagnostic sensing system.  His experience is that while the Jabsco pump itself is good quality, the relatively new sensor technology and threshold settings (to sense and respond to anomalies) have had significant issues. He gave specifics he's seen that are similar to those on the web. His experience is that the "Mark 2" (his name) has significantly adjusted voltage, pressure, and other thresholds that alleviate the "false positives" that created many problems.  While too early to assess L/T reliability, he feels the fundamental problems have been alleviated.   I don't believe I'm just getting a sell job.  He had a healthy skepticism of the competitive feature arms race among pump suppliers.

I go to this length not because I'm advocating anything, but  because (as an ex-marketing guy) I understand how a few anecdotal negative reviews can affect consumer choice.  My contribution to "net neutrality".

I'll probably go with this pump primarily on his experience and trust that his company will stand behind the product.  If that's a bad decision, this forum will be the first to know!

Stu Jackson

Julian, understand completely.  The other, and perhaps, larger question, is why bother to go with a high pressure and flow pump at all?  Our boats only need 3.0 gpm and 25 psi anyway. 
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

Julian Elliott

Saw this as a chance to boost pressure, which I always found a bit weak.  Maybe overkill, but there you go...

mainesail

Quote from: Julian Elliott on June 10, 2014, 05:23:09 PM
Saw this as a chance to boost pressure, which I always found a bit weak.  Maybe overkill, but there you go...

If you want more pressure just use a "wash down pump". The are the identical pumps only with a higher PSI setting and more current draw. I regularly install wash down pumps for customers with on board water filters... Stay away from the variable speed pumps until the bugs are worked out..
-Maine Sail
Casco Bay, ME
Boat - CS-36T

https://marinehowto.com/

Wayne

Do you really need more pressure?  Flow will increase with pressure, meaning you will run through your water tanks more quickly.  I've gone the other direction . . . reducing pressure to some faucets where not so much water was needed.
2006 MKII Hull # 1762
San Francisco, Ca