How long does a water pressure pump last

[nbfiresprite]

I have two jabsco 4's pumps, one each on the hot and cold, Now in the eighteen year of service

[rusty69]

I suppose what is really required is the number of hours use before failure (impossible to say) . Saying my pump lasted 18 years or 2 years means very little,though qualified with full time live aboard gives a little more info, is still not 100% meaningful. 

 

We have a shurflo pump on our sailing boat. It is at least 15 years old.  A shurflo on our full time liveaboard (2 onboard) would typically last 2 years. 

Edited January 31, 2019 by rusty69

[Ssscrudddy]

Thanks for all the replies.

This is interesting, it means my whale pump was no good from day 1.

14 hours ago, dmr said:

When the pressure switch starts to go it sounds wrong, slows down and hesitates a bit before turning off, but a good one turns off cleanly.

 

...................Dave

I reckon its most likely the pressure switch, but can't see anything. Sadly I can't put the pump back together again as 1 bit that was supposed to just pull off from the motor just won't come off the spline, & I need to get underneath that bit to screw it back together again. 

I'll try a jabsco next time. I have 1 of those square D pressure switches. 

[Sea Dog]

14 minutes ago, Ssscrudddy said:

Sadly I can't put the pump back together again as 1 bit that was supposed to just pull off from the motor just won't come off the spline, & I need to get underneath that bit to screw it back together again. 

Ah, you've fallen for the old "reassembly is the reverse of disassembly" gag!

 

[DandV]

I have a sneaky suspicion that many of the pump failures due to premature pressure switch failure are not a problem of the pump but of the boat's water reticulaion system with it's multiple sources of pressure loss and consequent short cycling. Apart from any pipeline leaks, any drips in any taps and shower fittings, and any passing of valves in the toilet make up system, washing machine or hot water PRV will provide continuing work and stress on the water pump and pressure switch. Lime scale is a constant impediment to tight sealing valves.

[rusty69]

The pressure switch in most cheaper pumps appear to be a simple microswitch. I wonder what the MTBF is for this type of switch. 

 

They certainly don't appear to be robust enough to last in the harsh environment of a full time live aboard  hence the square d type switch many people opt for. 

 

The other alternative i spose is a better pump. Someone mentioned another jabsco a few weeks back, but it was 300-400 quid. 

 

 

Edited January 31, 2019 by rusty69

[DandV]

6 minutes ago, rusty69 said:

The pressure switch in most cheaper pumps appear to be a simple microswitch. I wonder what the MTBF is for this type of switch. 

 

They certainly don't appear to be robust enough to last in the harsh environment of a full time live aboard  hence the square d type switch many people opt for. 

 

The other alternative i spose is a better pump. Someone mentioned another jabsco a few weeks back, but it was 300-400 quid. 

 

 

From memory the internal of a square D pressure switch is just a (good quality) micro switch

[rusty69]

1 minute ago, DandV said:

From memory the internal of a square D pressure switch is just a (good quality) micro switch

Yes, i think you are right. We have one, it is far more substantial than the build in ones, though they only cost a couple of quid to replace. 

 

I tend to use the build in switch until it fails, then cut the cable and connect up the square d. Coincidentally, the built-in switch failed yesterday. 

[Nightwatch]

My pump, a Shurflo, has, since me reading this thread, has started acting funnily. By that I mean it's taking longer to switch off after tap closure. Any ideas. At present it doesn't leak. Phew! Could it be that the pressure needs adjustment? Is it summat else.

 

We inherited this pump when we purchased Nightwatch in 2005. Since, I have carried out the usual repair kit replacement three times. It's a metal casing unit. It seems pumps are pumps and all have their downfalls.

22 minutes ago, rusty69 said:

Yes, i think you are right. We have one, it is far more substantial than the build in ones, though they only cost a couple of quid to replace. 

 

I tend to use the build in switch until it fails, then cut the cable and connect up the square d. Coincidentally, the built-in switch failed yesterday. 

Wot it this 'square d' you all speak of?

[rusty69]

Just now, Nightwatch said:

My pump, a Shurflo, has, since me reading this thread, has started acting funnily. By that I mean it's taking longer to switch off after tap closure. Any ideas. At present it doesn't leak. Phew! Could it be that the pressure needs adjustment? Is it summat else.

Ha ha. Exactly the same as mine did. Solution.... Don't read this thread. 

 

 

I wonder if the colder weather makes them sluggish

[Nightwatch]

Just now, rusty69 said:

Ha ha. Exactly the same as mine did. Solution.... Don't read this thread. 

 

 

I wonder if the colder weather makes them sluggish

My thought also. Cold weather results in thicker water.

[rusty69]

7 minutes ago, Nightwatch said:

 

Wot it this 'square d' you all speak of?

It is a heavy duty pressure switch, used to replace the internal pump switch.It requires plumbing in to the water supply, and wiring up to the pump to bypass the internal switch. 

 

 

 

Edited January 31, 2019 by rusty69

[rusty69]

6 minutes ago, Nightwatch said:

My thought also. Cold weather results in thicker water.

I'm gonna go and give my pump a cuddle, see if it improves things.

[roland elsdon]

Used to last many years ( shoreflow) now 25 months as warranty is 24.

if you have lost the receipt and paid cash they fail before 2 years.

i am not joking.

its not worth replacing just the pressure switch.

[WotEver]

4 hours ago, Sea Dog said:

Ah, you've fallen for the old "reassembly is the reverse of disassembly" gag!

 

Didn’t you just love that in the Haynes manuals?

[ditchcrawler]

5 hours ago, DandV said:

I have a sneaky suspicion that many of the pump failures due to premature pressure switch failure are not a problem of the pump but of the boat's water reticulaion system with it's multiple sources of pressure loss and consequent short cycling. Apart from any pipeline leaks, any drips in any taps and shower fittings, and any passing of valves in the toilet make up system, washing machine or hot water PRV will provide continuing work and stress on the water pump and pressure switch. Lime scale is a constant impediment to tight sealing valves.

Not in my case, I can easily draw a kettle of cold water if I do it just after the pump stops, before it will cut in again. I have a hot water expansion tank and 2 cold water accumulators.

 

[Stilllearning]

1 hour ago, WotEver said:

Didn’t you just love that in the Haynes manuals?

“To replace clutch, first remove engine”*

* see chapters 1,2,3,4 and 7.

[WotEver]

5 minutes ago, Stilllearning said:

“To replace clutch, first remove engine”*

* see chapters 1,2,3,4 and 7.

 

Yet with a bit of lateral thinking you can remove the radiator to give some space, remove the rear mounts, then have sufficient clearance to tilt the whole shebang down to remove the gearbox. 

[ditchcrawler]

5 hours ago, DandV said:

I have a sneaky suspicion that many of the pump failures due to premature pressure switch failure are not a problem of the pump but of the boat's water reticulaion system with it's multiple sources of pressure loss and consequent short cycling. Apart from any pipeline leaks, any drips in any taps and shower fittings, and any passing of valves in the toilet make up system, washing machine or hot water PRV will provide continuing work and stress on the water pump and pressure switch. Lime scale is a constant impediment to tight sealing valves.

I have dumped 3 pumps and in every case it was due to body leaks, the pressure switch was fine

[Stilllearning]

13 minutes ago, WotEver said:

 

Yet with a bit of lateral thinking you can remove the radiator to give some space, remove the rear mounts, then have sufficient clearance to tilt the whole shebang down to remove the gearbox. 

Depending on what car we are discussing. On an Austin Healey Sprite Mk 4, it was easiest to remove the radiator and grille, then lift out the engine.

[BruceinSanity]

22 minutes ago, Stilllearning said:

“To replace clutch, first remove engine”*

* see chapters 1,2,3,4 and 7.

Useful collection of Haynes interpretations here: http://slroc2.co.uk/index.php/forfun/interpreting-the-haynes-manual

 

Incidentally, and totally , visiting the International Bomber Command Centre memorial last weekend, I was entertained to see they had a Haynes manual for the Lancaster bomber and other WWII aircraft.

[WotEver]

1 hour ago, BruceinSanity said:

Incidentally, and totally , visiting the International Bomber Command Centre memorial last weekend, I was entertained to see they had a Haynes manual for the Lancaster bomber and other WWII aircraft.

They have one for the Vulcan bomber too. I bid in an auction for one signed by the last Vulcan active aircrew but was seriously outbid. 

[blackrose]

On 30/01/2019 at 13:22, BruceinSanity said:

In my experience, anything from two to four years of continuous use.

I doubt any pump would last that long if used continuously. ?

[blackrose]

My previous pump was a Shurflo aquaking and lasted about 4 years of full time liveaboard use. I replaced the seal between the motor and head as it was leaking and got about another year out of it before it started leaking again. Then I replaced it with a Jabsco parmax 3. That started leaking very slightly after about 3 years. It was actually sucking in air but I fixed it with a bit of PU sealant (Stixall) and it's been running fine ever since (touch wood) and that was about 6 years ago. I'll definitely buy another Parmax when this one's finished.

22 hours ago, ditchcrawler said:

People say to me , why dont you mount that in a box with soundproofing, my reply is I want to know its running.

Yes and I also want to be able to hear if my system is leaking.

[ditchcrawler]

2 hours ago, blackrose said:

 .It was actually sucking in air but I fixed it with a bit of PU sealant (Stixall) and it's been running fine ever since (touch wood) and that was about 6 years ago. I'll definitely buy another Parmax when this one's finished.

 

Maybe we should go round the outside of them with sealant when they are brand new?