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Replacing a water pump


BlueStringPudding

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It may mean that you have to run a new, thicker cable but how easy/difficult that will be depends upon the design of the boat and where the cables run. If you have space under the catwalk/gunnels you may be able to screw clip top plastic trunking to the underside and then running new cable becomes a lot easier. I am more concerned about volt drop up the cable because if its too much it can burn out pumps. In fact if you feel you are suffering low flow rates then that may be as a result of volt drop on the cable.

 

I ran my system at between 10 and 15 psi and had perfectly adequate flow. Remember most people do not have all their outlets running at once.

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1 minute ago, mrsmelly said:

Par max 4 120 squids new on fleabay delivered. Fwiw when my par max 4 went tits up I replaced with parmax 1 at less money and it works perfectly, did the same on my last boat. 

There are many different ratings of Par Max 4, though. What I need is 20psi, with a 10A fuse. Already seen one advertised on Amazon that has a 10A fuse but it is 25psi.  if I'm paying a couple of hundred quid, I need the right spec (and a warrantee).

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1 minute ago, BlueStringPudding said:

There are many different ratings of Par Max 4, though. What I need is 20psi, with a 10A fuse. Already seen one advertised on Amazon that has a 10A fuse but it is 25psi.  if I'm paying a couple of hundred quid, I need the right spec (and a warrantee).

To be honest they all work. I've changed several on my own and hire boats over the years. There is nowt much to choose. If I were u I would buy bog standard 80 quid one and fit and it will be fine. Narrowboats are all much of a muchness with pipe calorifier etc and instant heater if u have one. Very quick easy job ?

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1 minute ago, mrsmelly said:

To be honest they all work. I've changed several on my own and hire boats over the years. There is nowt much to choose. If I were u I would buy bog standard 80 quid one and fit and it will be fine. Narrowboats are all much of a muchness with pipe calorifier etc and instant heater if u have one. Very quick easy job ?

I tend to agree with this. I suspect BSP is overthinking it and wants to be 100% sure it will all work without more problems.

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2 hours ago, Tony Brooks said:

I tend to agree with this. I suspect BSP is overthinking it and wants to be 100% sure it will all work without more problems.

Yes. I do want to be 100% sure it will all work without more problems. Pretty basic expectations though, don't you agree? ?

 

But I don't for one minute believe that a pump with a flow of 7lpm or 3lpm will be give anywhere near as decent a shower as one with a flow of 14.4lpm at 10-20psi. That's just common sense, surely? 

 

Trying to compare Jabsco pumps is hard enough, but I've just noticed that the spec on their website is contradicted by the spec for the same model on the pdf. One spec would be an adequate replacement, the other needs a bigger fuse. Which one is a typo? Who knows!? Aargh!

 

Looking at Jabsco 10A only pumps, coz I'm stuck with the electrics I've got, these are the options:

 

Current leaking pump that I'm trying to get a good match for the spec, but it's no longer made (parts may be obtainable for a repair but it's a very old pump):
JABSCO 30620-0292 PAR MAX 4
12v
Flow 14.4lpm
Cuts in at 10psi
Cuts out at 20psi
6A draw
10A fuse

Available To buy:
JABSCO 31620-0292 PAR MAX 4
12v
Flow 16.3lpm HIGHER
Cuts in at 10psi CORRECT
Cuts out at 25psi TOO HIGH
6A draw (on pdf spec sheet) CORRECT
10A fuse (on pdf spec sheet) but contradicted on website as 15A fuse.  TOO HIGH

JABSCO 31395-0392 PAR MAX 2.9
12v
Flow 11lpm LOWER
Cuts in at 20psi MUCH TOO HIGH
Cuts out at 40psi MUCH TOO HIGH
4.4A draw LOWER
10A fuse CORRECT

JABSCO 31600-0092 PAR MAX 3
12v
Flow 13lpm A BIT LOWER
Cuts in at 20psi MUCH TOO HIGH
Cuts out at 40psi MUCH TOO HIGH
Draw ?
Fuse 10A CORRECT

So it's not looking great for 10A fused pumps in terms of psi - and that's not just with Jabsco. Looking at Midland Swindlers 10A only pumps, there's

JABSCO PAR MAX 7l

12v

Flow 7lpm LESS THAN HALF, TOO LOW

Cuts in at ?

Cuts out at 25psi TOO HIGH

Draw 3.5A OKAY 

Fuse 10A CORRECT

 

WHALE PUMPS TOO TALL AND WRONG SHAPE FOR PRESENT INSTALLATION

 

JABSCO PAR MAX 1

12v

Flow 3.7lpm TOO LOW

Cuts in at ?

Cuts out at 35psi TOO HIGH

Draw ?

Fuse 10A CORRECT

 

SHURFLOW AQUA KING 2 JUNIOR

12v

Flow 7.6lpm TOO LOW

Cuts in at ?

Cuts out at 20psi CORRECT

Fuse 3.5A (weirdly low - can't be powerful enough, surely?)

 

All other SHURFLO have much too high cut out psi.

 

(I just thought to check the destructions for the toilet plumbing, as I aspire to have it flushing properly with fresh water one day and I vaguely recall it had a minimum requirement from the water system. It needs a water pump with a flow of at least 11lpm. So that narrows down the water pump choices with one fell swoop - the piddly ones won't work). 

 

So for now, those are my options. None took good to me. A phone call to Jabsco to get them to verify the fuse rating of the 31620-0292 Par Max 4 might be sensible since they haven't answered my email yet. If they confirm it needs a 15A fuse not a 10A, then it looks like I need to try replacing some parts on the old leaking pump. Not my area of expertise, obviously. ?

Edited by BlueStringPudding
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What you need to do is by-pass the built-in pressure switch and fit a inline Adjustable Water Pump Pressure Switch 

in the pipe work just after the accumulator using a T junction. Which is what I did when the  built-in pressure switch

failed in my Par-Max-4. The pump fitted switch was removed and replaced with a blanking plate.   

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1 hour ago, BlueStringPudding said:

Yes. I do want to be 100% sure it will all work without more problems. Pretty basic expectations though, don't you agree? ?

 

But I don't for one minute believe that a pump with a flow of 7lpm or 3lpm will be give anywhere near as decent a shower as one with a flow of 14.4lpm at 10-20psi. That's just common sense, surely? 

 

Does the pump cycle on and off while the shower is in use? If so then the pipework and shower are limiting the water flow, not the pump output. If not then there will be a reduction in flow from the shower but unless you have a domestic "rain type" shower head I doubt this is the case.

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12 hours ago, Tony Brooks said:

Does the pump cycle on and off while the shower is in use? If so then the pipework and shower are limiting the water flow, not the pump output. If not then there will be a reduction in flow from the shower but unless you have a domestic "rain type" shower head I doubt this is the case.

Thanks, Tony. No, it doesn't. It turns off when the shower turns off. And it runs continuously when the shower is on. Always has done. Same for all the taps. But whatever, I won't be replacing all the boat's pipe work (or its electric cabling). It would be overkill for a system that's worked fine for 20+ years. The toilet flush needs a flow of 11lpm minimum and the pump fuse can't be bigger than 10A, so that's pretty much defined the spec of the new pump. All I need to find now is one with the same psi. That's proving difficult as most new ones are too high.

Edited by BlueStringPudding
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12 hours ago, nbfiresprite said:

What you need to do is by-pass the built-in pressure switch and fit a inline Adjustable Water Pump Pressure Switch 

in the pipe work just after the accumulator using a T junction. Which is what I did when the  built-in pressure switch

failed in my Par-Max-4. The pump fitted switch was removed and replaced with a blanking plate.   

That's a new suggestion. Thanks. Out of curiosity, why is bypassing the pressure switch with an external one and having to find a blanking plate/gasket/extra pipe work; better than just just replacing the pressure switch?

 

 

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I wonder if you're over thinking a wee bit here BSP?

 

My boat is a pretty bog standard in terms of her systems, Piper having made a good choice of readily available, decent quality kit all round.  My water pump is a Par Max 2.9, which keeps within your current (Amp) limits, but does not appear to comply to your pressure specs. However, it works quite happily in real life in my typical 57'  situation, where it sits in the bow, the internal pressure switch  unmodified. Paired with an accumulator just downstream (despite Jabsco's assertion that it doesn't need one) and a 3 bar pressure relief on the midships calorifier, it provides a decent flow at the galley and bathroom sinks and a good shower half way down the boat. It cuts in a few seconds after a tap is opened, cuts out a few seconds after a tap is closed, runs continuously when the shower is on, and doesn't disturb the PRV. Is there something about your set up which means this won't be the same for you?

 

Forgive me if I've missed something, but the theory seems to be generating more heat than light here - I'm just trying to offer a pragmatic view. :)

 

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Well, I've had a fun time playing phone call relay between Jabsco and Midland Chandlers this morning. But I'm so pleased to have finally spoken to the chaps at Jabsco. Couldn't have been more helpful. And I'm pleased I didn't just opt for any old cheap pump because they've explained how different flow rates and the other specs would affect the operation of various bits of plumbing. And I now have a way forward.

[Warning: this is a bit like listening to Rimmer explain his game of Risk in Red Dwarf, so unless you like a tedious yarn, feel free to skip to the last paragraph ?]

After Jabsco ruled out some different water pump options because they weren't happy how they would run with my hireboat plumbing/electrics, including ruling out a refurbishment of the old pump because it's such a well-used OAP that I'll be refurbishing different parts of it forever; and then ruled out smaller pumps because of reduced water flow to taps and shower, and their inability to flush the toilet (also a Jabsco), their verdict is that I should order the 31620-0292 Jabsco water pump even though it takes a higher fuse and has a slightly higher psi. Their logic being that the flow rate is very important and must be a fair bit higher than, not equal to or lower than 11lpm for my boat. They said that based on their experience, the +5psi max pressure of the new pump isn't a high enough difference to cause the PRV to keep leaking or any other problems anywhere in the system. And I'll be running the pump through my current 10A fuse protected wiring instead of the new pump's advised 15A fuse - this is at Jabsco's recommendation because its start-up draw is relatively low. They think it's very unlikely to ever blow the 10A fuse, even acknowledging my 20+ year old Black Prince electrics. But if the 10A fuse does keep blowing, they will refund me for the whole pump; even though it will have been used. So I'm covered. How nice of them. ? 

Next was resolving postage/delivery while living aboard during plague season. Jabsco usually offer Royal Mail delivery on most items ordered though their website (meaning it could be collected from a local Delivery Office) except, it turns out, things as heavy as a water pump. ? But Jabsco were sure Midland Chandlery stock that model of pump. So I checked the chandlery website and phoned their customer service, but they don't stock it anymore. Midland Chandlers' customer service lady advised me to speak to a branch to get them to order it in. So I phoned them. But staff there told me Jabsco are really slow with orders, it would take at least 3 weeks and wouldn't I much prefer a totally different Jabsco ParMax4 called the 0392 that also needs a 15A fuse and can be picked up straight off their shelf?  I looked it up on the Jabsco website and it needs a 20A fuse not a 15A one ?. So I phoned Jabsco again to double check, who advised me not to buy that one, because it definitely needs a 20A fuse and doesn't even take the same diameter pipes that the 0292 does ?. Jabsco chap chuckled about the chandlery trying to flog me something easy off the shelf, instead of something right, while checking the status of the Midland Chandler account with them. From that he assured me that they have always offered next day delivery for Midland Chandlers, there won't be a 3 week wait, and that if the Chandlers place the order with Jabsco by 2pm today, the correct pump will be delivered tomorrow, ready for Tree Monkey to pick up on Saturday (thank you Monkey man ?) -  since Monkey needs to buy some chandlery stuff including, ironically, a new water pump for his boat too. So I phoned back Midland Chandlers again, broke the news that their 0392 pumps are incorrectly labelled; checked they've got in stock Monkey flavoured water pumps so he won't have a wasted trip, and Midland Chandlers are going to order the 0292 pump for me from Jabsco today, and phone me to confirm when it arrives. Phew! A lot of to-ing and fro-ing but it looks like we got there in the end. I didn't expect it to be as complicated, and I'm pleased all the specs were properly factored in.

So there we go: on Jabsco's advice, I'm going for a slightly higher psi and current, but running it through my lower 10A fuse - and Jabsco will ensure that I get a refund of the cost of the pump if the fuse keeps blowing, even if bought through Midland Chandlers.  Pretty much the best resolution I could get, I think. Good ole Jabsco. Maybe I'll get another 23 years out of this new one ?

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32 minutes ago, BlueStringPudding said:

And I now have a way forward.

Funny how the simple answers are so often the best.... :giggles:

 

Seriously, glad you got to the bottom of it and have a way ahead. I hope the solution works out well...

 

...whatever it is! :D

 

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On a related note that's not worth starting a new thread over: what are the water-soaky-uppy sausages called? 

 

You know what I mean - looks like a draught excluder but it soaks up water. You can get ones for diesel that can be put in the bilge. But I want a new water one, since I'm growing some delightful mycelium around the old soggy one (matron) 

 

I've searched on the Swindlery website for terms like "absorbent" and "water" and "sock" but nowt is coming up. Maybe "water-soaky-uppy sausage" is the actual term... ?

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15 minutes ago, BlueStringPudding said:

On a related note that's not worth starting a new thread over: what are the water-soaky-uppy sausages called? 

 

You know what I mean - looks like a draught excluder but it soaks up water. You can get ones for diesel that can be put in the bilge. But I want a new water one, since I'm growing some delightful mycelium around the old soggy one (matron) 

 

I've searched on the Swindlery website for terms like "absorbent" and "water" and "sock" but nowt is coming up. Maybe "water-soaky-uppy sausage" is the actual term... ?

Good words to search with include spill, like spill sock, spill pad. For example.

Jen

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Cheapo supermarket own brand disposable nappies are designed to soak up water and are a lot cheaper than spill socks etc.and easy to buy.

If you still want a sausage have a look at the MSC industrial site.  Next day delivery ic yoh order by IIRC 6 pm.   and they have never let me down.

N

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57 minutes ago, BlueStringPudding said:

On a related note that's not worth starting a new thread over: what are the water-soaky-uppy sausages called? 

We need more context here.  On an elephant it's called a trunk, but I'm not sure that's what you're after. ;)

 

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1 hour ago, BEngo said:

Cheapo supermarket own brand disposable nappies are designed to soak up water and are a lot cheaper than spill socks etc.and easy to buy.

If you still want a sausage have a look at the MSC industrial site.  Next day delivery ic yoh order by IIRC 6 pm.   and they have never let me down.

N

Thanks. I'm using nappies because the ancient sock that's there isn't containing all the water. But nappies can't be left in place once the pump is replaced coz they like to burst and leak weird porridge everywhere. So I thought I would replace the sock once this is all done. ?

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7 minutes ago, BEngo said:

OThe other way to protect against a future leak is to put the pump in a cheap roasting tin on a bit of rubber sheet (old car floor mat) to stop tinny noises.

N

and this topped with a cheapo water alarm in the roasting dish and you'll get notified of problems before any damage - if you're onboard of course!

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52 minutes ago, robtheplod said:

and this topped with a cheapo water alarm in the roasting dish and you'll get notified of problems before any damage - if you're onboard of course!

Which is exactly what I have and it did alert me to the last pump failing

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14 hours ago, BlueStringPudding said:

That's a new suggestion. Thanks. Out of curiosity, why is bypassing the pressure switch with an external one and having to find a blanking plate/gasket/extra pipe work; better than just just replacing the pressure switch?

 

 

Simple, the external inline pressure switch is adjustable (the settings can be changed). Cheaper, the switch only cost a fiver plus a quid for the T junction at the time. Ely swindlers charged me £30 for the pump switch and ordered the wrong one, Then refused to refund as I had opened the box breaking the seal. As for the blanking plate, a few minuites to make.       

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On 12/11/2020 at 16:24, robtheplod said:

and this topped with a cheapo water alarm in the roasting dish and you'll get notified of problems before any damage - if you're onboard of course!

 

You also need to periodically replace the water alarm battery for continued protection. ? I replace mine annually. 

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On 13/11/2020 at 00:30, nbfiresprite said:

Simple, the external inline pressure switch is adjustable (the settings can be changed). Cheaper, the switch only cost a fiver plus a quid for the T junction at the time. Ely swindlers charged me £30 for the pump switch and ordered the wrong one, Then refused to refund as I had opened the box breaking the seal. As for the blanking plate, a few minuites to make.       

External pressure switches have better duty ratings than the flimsy built in units. Also, if fitted before the existing switch leaks, then you just need to by pass the switch by cutting the wiring to it.

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Progress report:

New water pump was installed last week.

But it cycles on and off when a tap is open, causing the water flow to alternate fast and slow. A quick phone call to the Jabsco boys last week diagnosed that the accumulator needed to be reset. (They got me to check no water was coming from the valve so a leaking accumulator bladder was ruled out). So I ordered a bike pump with gauge online. Which I used this morning.

With water in the pipes to full pressure and power to the pump turned off, the gauge showed 0psi in the accumulator tank. I pumped it up but as I did so, I noticed the pressure slowly dropped again on the gauge. I checked the pump fittings were tight and pumped it up to 5.77psi (Jabsco advised between 5 and 6 psi) - which was quite tough to achieve. Any loss in pressure slowed right down which I thought was promising, so I quickly unscrewed the pump from the accumulator valve. But the rather loud hissing noise (and I could feel the rush of air) made it quite clear that all the pressure was lost in a couple of seconds before I could screw the protective plastic cap back on to the accumulator valve. ? Is there a knack to this I don't know about? 

Edited by BlueStringPudding
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