Pressure switch on water pump playing up.

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fredrussell

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I have the usual pressurised water system on my boat. Of late the pressure switch has been playing up. That is to say, pump doesn’t operate when tap ‘opened’. If you bypass pressure switch (with pos wire straight to pump pos terminal) it runs as normal. No corrosion on terminals. It’s intermittent over last couple of days. I’ve waggled wires, given the pump a tap, etc but no joy. It’s a Flo King pump. Are these pressure switches user serviceable?
 
Flo-King pumps aren't very common. If you can remove the pressure switch, you may find that another make's switch will fit. Otherwise, it may be time for a new pump.
 
Rogershaw said:
Don't know that pump but whale do a separate inline pressure switch which could be fitted and connected to the existing pump
Click to expand...

That's a very good suggestion, but it's almost half the price of a complete new pump, so if the Flo-King is fairly old it might be better to replace it.
 
Some of those older Flo KIng pumps had micro switches that could be changed and some parts interchanged with ShureFlo pumps, so might be worth taking apart and seeing what Foxs or Seamark Nunn stock.

Rogers Whale switch is a good idea if you have a high pressure/high volume pump (Mine is both and costs nearly £200, so would be worth a £30 switch). But if it's low pressure/volume, a Jabsco ParMax 2.9 isn't a fortune (as PVB suggests).
 
That in-line switch by Whale may be just the job actually, cheers Roger. Cheapest Shurflo pump is £55 on eBay or there are some uber-cheap Chinese offerings.
 
pvb said:
That's a very good suggestion, but it's almost half the price of a complete new pump, so if the Flo-King is fairly old it might be better to replace it.
Click to expand...
Just been through this hoop when my old Johnson pump started going febrile on me. Thought I had to abandon ship when 1st mate came on board and no fresh water to hand...ugh!

An 11 lir / min pump costs £70, and I think after these years of good service I shouldn't face down Mme Luck, so in it goes. Sorted for years to come.

Some things are worth buying new IMHO.

PWG
 
I also had similar problems with a Jabsco pump.
I was able to bypass the fault by using the water pump switch on the main switchboard but this was clearly inconvenient.
I was sure that the unit could be fixed as the pump ran fine but I had a cruise coming up so gave up and replaced the entire unit. As Peter says, for £70 this seemed a pragmatic decision to keep my crew happy. Had it failed when I had more time to investigate I might have tried to fix it a bit longer.
 
It is a disgrace that a perfectly usable device needs to be scrapped for the cost of a pressure switch. I keep thinking, in these cases, of all that copper going to landfill and reading, at a similar time, of the plight of those working in copper mines in 3rd world countries.

Jonathan
 
This is a case where if the OP was to throw the pum away for a malfunctioning pressure I would remove it from the dumpster and repurpose it as a flushing water pump for a manual head together with a electric diaphragm extraction pump.

I also have a repurposed pressure pump a a screen washer for the front window of my wheelhouse together with a windscreen wiper
 
PaulRainbow said:
Some of those older Flo KIng pumps had micro switches that could be changed and some parts interchanged with ShureFlo pumps, so might be worth taking apart and seeing what Foxs or Seamark Nunn stock.

Rogers Whale switch is a good idea if you have a high pressure/high volume pump (Mine is both and costs nearly £200, so would be worth a £30 switch). But if it's low pressure/volume, a Jabsco ParMax 2.9 isn't a fortune (as PVB suggests).
Click to expand...
And the Jabsco ParMax has a replaceable pressure switch. After two switch failures in 4 years I now carry a spare pressure switch
 
Both "genuine " ?? and knock off micro switches on Ebay.
Fitted one about three years ago still going strong.
So cheap bought two , kept one as spare.
Think I paid about £5.00 with postage .
*GENUINE* Micro Switch Shurflo Motorhome RV Caravan Camper Boat Water Pump NEW | eBay
Remove duff switch and get part number .
This generic switch is used in zillions of other things none of which priced with a marine markup, then just pop on to Ebay and type in microswitch.
 
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Just to update, I used a Whale pressure switch and it works well. My friend has an old caravan dying slowly in his garden so I got the switch from that. Nice (and rare, sadly) to be able to fix a boat issue for nowt.
 
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I had a similar problem recently. It was caused by the diaphragm not being properly seated and pressure being equal on both sides so the micro switch was not activated. Reseating the diaphragm was the solution.
 
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