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Which domestic water pump?


MtB

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About thee years ago I replace the leaking Shurflo pump in the boat belonging to a friend of mine with a new Shurflo pump pretty much the same, and already this new one is leaking again. A bit of investigation reveals the pressure switch hysteresis is massive. Switches ON at about 1.3bar as expected, then OFF at 4.5bar. Probably why it leaks, and time to replace the whole thing again I reckon. 

So which make and model of pump to fit? Looking for a cheap and cheerful one equivalent to the old one, which according to the label is 30psi, and 3 gallons per minute/11.3 litres per minute. (Yes that is what it says!)

Any suggestions for a similar but reliable pump, not made by Shurflo please?

Many thanks...

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The usual recommendation seems to be something from the Jabsco ParMax range.

The ParMax 2.9 has a similar 11 litres per minute flow rate to the Sureflo one that is failing.

You do need however to look closely at the pressure ratings, I think, because from memory I think there are similarly named versions that cut out at different pressures.

We replaced a Sureflo with a ParMax on Chalice, and that was fine.  Flamingo also has a ParMax, (actually 2, as there is a standby one also plumbed in), but water flow seems more erratic, perhaps because it is expected to travel much of the length of the boat, and in some cases half way back again.  These pumps may well be lower pressure versions than the one we installed on Chalice - I'm not absolutely sure.

 

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Another vote for the Par Max 2.9.  Good price at marinesuperstore.com.  Gives all the details for the pump.  I think the cut in is 15 PSI and cutout is 30psi.

 

ETA:  I recently replaced one due to flaky pressure swith, this after ten years at approximately 50% occupation.

Edited by dor
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What am I doing wrong? -

I' only had two trail king (the caravan types) in 20 years - holiday and weekend use - methinks it may be because I'm a cheapskate and only fit the 7l / minute variety. gives a reasonable shower rate, but then I did fit a smaller shower head.

 

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Ok thanks for the feedback everyone. 

I have the Jabsco Parmax 2.9 in one of my boats and performance is so dismal I'm planning to change t, so I initially ruled it out. Maybe there is actually something wrong with it given several people here are happy with theirs. Maybe we'll go for the Parmax 3.5...

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25 minutes ago, Mike the Boilerman said:

I have the Jabsco Parmax 2.9 in one of my boats and performance is so dismal I'm planning to change t, so I initially ruled it out. Maybe there is actually something wrong with it given several people here are happy with theirs. Maybe we'll go for the Parmax 3.5...

As I said, I'm not convinced you can't get the same model number but with different cut out pressures.

Make sure I'm wrong before automarically thinking "more flow" rather than "more pressure".

1 hour ago, OldGoat said:

What am I doing wrong? -

I' only had two trail king (the caravan types) in 20 years - holiday and weekend use - methinks it may be because I'm a cheapskate and only fit the 7l / minute variety. gives a reasonable shower rate, but then I did fit a smaller shower head.

 

It is widely reported that older Sureflo pumps were more resiliant, and could be repaired, whilst the modern ones with far more plastic fail regularly, and repairs are far less likely to succeed.

I would no longer touch one.

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20 minutes ago, alan_fincher said:

As I said, I'm not convinced you can't get the same model number but with different cut out pressures.

Make sure I'm wrong before automarically thinking "more flow" rather than "more pressure".

 

It' the flow rate from my Parmax that is dismal, not the pressure. The pressure only develops against a closed or restricted outlet anyway. Once one opens a tap or shower, it is the flow rate the pump can deliver that governs the speed of the water pouring out of the tap. The Parmax 2.9 claims to deliver 11 litres per minute out of an open unrestricted pipe, the 3.5 claims to deliver 13 litres per minute. I think my Parmax is a 2.9 and I reckon it delivers about 5 litres a minute. I'm gonna measure it next time I visit the boat!

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4 hours ago, rusty69 said:

Swapped our Shurflo for a Jabsco Parmax 2.9 a couple of years back, it works well as replacement on our setup, was cheaper, but too early to comment on longevity. I have also heard good mutterings about Whale pumps.

Likewise, the Jabsco seems fine to date. If the Whale pressure pump is as good as the waste pump it will be an excellent piece of kit.

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2 hours ago, Mike the Boilerman said:

 

It' the flow rate from my Parmax that is dismal, not the pressure. The pressure only develops against a closed or restricted outlet anyway. Once one opens a tap or shower, it is the flow rate the pump can deliver that governs the speed of the water pouring out of the tap. The Parmax 2.9 claims to deliver 11 litres per minute out of an open unrestricted pipe, the 3.5 claims to deliver 13 litres per minute. I think my Parmax is a 2.9 and I reckon it delivers about 5 litres a minute. I'm gonna measure it next time I visit the boat!

That said, I bet the flow rate is a damn sight faster from your "nearest" cold tap than it will be if you are going through a Morco to your "furthest away" hot tap.

As I said when we replaced an 11 lpm Sureflow with an 11 lpm ParMax on Chalice I didn't notice any loss of flow, but 11 lpm ParMax on Flamingo has never seemed as good.  Perhaps wrongly, I have largely attributed that to much longer pipe runs, but I have never had any other pump on the same pipework for comparison.

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14 minutes ago, alan_fincher said:

That said, I bet the flow rate is a damn sight faster from your "nearest" cold tap than it will be if you are going through a Morco to your "furthest away" hot tap.

 

Well it jolly well ought to be regardless of pipe distances, given the Morco contains a flow restrictor to limit the flow!

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1 minute ago, Mike the Boilerman said:

 

Well it jolly well ought to be regardless of pipe distances, given the Morco contains a flow restrictor to limit the flow!

And are you saying that if you were to connect two different 11 litres per minute pumps to a Morco by the minimum of possible pipework, and one of those cut out at 20 psi, whereas the other cut out at 40 psi, the flow restrictor would result in water being delivered at exactly the same rate in each case?

I'm far from convinced, but will bow to any results obtained from practical experimentation.

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Quote

I think my Parmax is a 2.9

 

I find the Par Max 2.9 is more than adequate for a shower.   Are you sure you didn't fit a Par Max 1.9?

I originally fitted two pumps, one for the hot and one for the cold, as it was suggested that one pump wouldn't provide enough pressure.  However this made it difficult to balance the temperature even with a thermostatic mixer as it couldn't react fast enough to one of the pumps coming on.  I now just use one, with the other in place as a spare which can be brought in with the flick of a switch.

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9 minutes ago, dor said:

I find the Par Max 2.9 is more than adequate for a shower.   Are you sure you didn't fit a Par Max 1.9?

 

That's a possibility. I didn't fit the pump. I just remember it looking like a Parmax. Until you mentioned it I didn't realise there was. 1.9 size!

 

19 minutes ago, alan_fincher said:

And are you saying that if you were to connect two different 11 litres per minute pumps to a Morco by the minimum of possible pipework, and one of those cut out at 20 psi, whereas the other cut out at 40 psi, the flow restrictor would result in water being delivered at exactly the same rate in each case?

 

Nope. I'm saying the water will be slower from the Morco than from the unrestricted cold tap, whatever the pump switching pressure.

There are however, flow restrictors which will do exactly as you describe, but not in the Morco. 

Edited by Mike the Boilerman
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1 minute ago, ditchcrawler said:

Partly blocked inlet filter ?

 

 

Possible but highly unlikely. Its connected to a lovely clean stainless steel domestic water tank.

In 40 years of boating I've never encountered a blocked pump inlet strainer. 

They are pretty pointless in my opinion.

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2 hours ago, Mike the Boilerman said:

They are pretty pointless in my opinion.

Until something bocks an inlet valve in the pump. My inlet strainer hardly ever clogs but when I strip it there are always some hard bits in it. Also a SS tank but with some mild steel pipework that’s part of the boat

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On 10/01/2018 at 11:45, Mike the Boilerman said:

About thee years ago I replace the leaking Shurflo pump in the boat belonging to a friend of mine with a new Shurflo pump pretty much the same, and already this new one is leaking again. A bit of investigation reveals the pressure switch hysteresis is massive. Switches ON at about 1.3bar as expected, then OFF at 4.5bar. Probably why it leaks, and time to replace the whole thing again I reckon. 

So which make and model of pump to fit? Looking for a cheap and cheerful one equivalent to the old one, which according to the label is 30psi, and 3 gallons per minute/11.3 litres per minute. (Yes that is what it says!)

Any suggestions for a similar but reliable pump, not made by Shurflo please?

Many thanks...

Flojet?

https://www.ebay.co.uk/i/122175530257?chn=ps&adgroupid=47842945425&rlsatarget=pla-379969407002&abcId=1129946&adtype=pla&merchantid=7262114&poi=&googleloc=9046814&device=t&campaignid=974959912&crdt=0&ul_ref=http%3A%2F%2Frover.ebay.com%2Frover%2F1%2F710-134428-41853-0%2F2%3Fmpre%3Dhttps%253A%252F%252Fwww.ebay.co.uk%252Fi%252F122175530257%253Fchn%253Dps%26itemid%3D122175530257%26targetid%3D379969407002%26device%3Dt%26adtype%3Dpla%26googleloc%3D9046814%26poi%3D%26campaignid%3D974959912%26adgroupid%3D47842945425%26rlsatarget%3Dpla-379969407002%26abcId%3D1129946%26merchantid%3D7262114%26gclid%3DCj0KCQiAs9zSBRC5ARIsAFMtUXF247b20xeM_9Gx6iMAYh1QAEhB3aLfhEzbQLQo1gvNLhVg82ghz2MaAp99EALw_wcB%26srcrot%3D710-134428-41853-0%26rvr_id%3D1414052803040

I haven't studied the spec in detail but the one in our caravan works fine and doesn't leak.

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