Water Pump - help needed please

[LeonC]

I managed to get away last September to take part in the Tour de France (I didn't win!)

That's the good news - the bad news is, the submersible water pump failed while I was there. What with all the extra hand-washing I managed to leave the bathroom tap open but the shower attachment switched off, so no water was coming out but the water pump was still on whilst I was driving along. Couldn't hear it because I always have music playing.

To cut a long story short, I got someone to replace the pump but it's permanently on unless I turn the power off. The guy who fitted it wanted to remove all the wood surrounding the water tank (inboard, under the rear bed) to see if there is a "Water Pressure Relief Valve" of some sort. I'm very reluctant to let him do this. Does anyone know if such a thing exists, and why would they hide it away.

I have a 2018 Globecar Campscout and the water pump is a Comet Lux-Plus submersible.

I've read a couple of similar threads from a year or two ago (apparently this is quite common!) and a very good suggestion from several people was to install an isolation switch to the pump. This sounds like a very good idea, but I thought I'd ask you lot for suggestions also.

Thanks in advance.

 

[dabhand]

Have you checked the pump isn’t on continuous on the heating panel, many vans have an option and on my panel it’s quite easy to do inadvertently

 

[Richard n Ann]

There's usually a drain valve near the water heater. Make sure that's shut.

 

[LeonC]

There's usually a drain valve near the water heater. Make sure that's shut.

Yes, done that. Thanks.

 

[LeonC]

Have you checked the pump isn’t on continuous on the heating panel, many vans have an option and on my panel it’s quite easy to do inadvertently

Just been out to double-check. The control panel in the Globecar is very simple and the heating controls are separate, but thanks for your input.

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[pappajohn]

Submersible pumps are normally switched by microswitch taps.
Yours sounds like a microswitch has melted/shorted closed.

 

[SandraL]

There are 2 standard ways converters use to turn the pump on.
1, micro switches in the tap. When tap is opened the switch is made and the pump turns on. If you have these you will see 2 thin wires exiting underneath the taps. Each tap will have a switch. If a switch fails short circuit the pump will run continuously, although they often fail with a snapped wire in which case the pump doesnt run when that tap is opened
.
2 A pressure switch, with this as you turn on the tap there will be a drop in pressure, the pressure switch will turn on and activate the pump. When tap is closed pressure will rise and tap will turn off. These pressure switches are usually adjustable.

Which system does your van have?

 

[Eggs]

Are all the taps working when the pumps running?

 

[Bognor Saint]

We have the same water pump in our dethleffs. It failed on second to last day of our trip last September. Sorted under warranty but I bought a spare in case it happens again. Not expensive , about £20 online.

 

[LeonC]

There are 2 standard ways converters use to turn the pump on.
1, micro switches in the tap. When tap is opened the switch is made and the pump turns on. If you have these you will see 2 thin wires exiting underneath the taps. Each tap will have a switch. If a switch fails short circuit the pump will run continuously, although they often fail with a snapped wire in which case the pump doesnt run when that tap is opened
.
2 A pressure switch, with this as you turn on the tap there will be a drop in pressure, the pressure switch will turn on and activate the pump. When tap is closed pressure will rise and tap will turn off. These pressure switches are usually adjustable.

Which system does your van have?

Mine has microswitches.

Are all the taps working when the pumps running?

Yes, both the bathroom and kitchen taps and the loo now work fine.

Submersible pumps are normally switched by microswitch taps.
Yours sounds like a microswitch has melted/shorted closed.

The microswitches appear to be okay, but I have to turn off the main control panel to turn the pump off.

I originally tried to repair this myself but when I removed the top half of the bathroom tap I heard the water pump briefly whirr into life, leading me to believe the pump was okay and the problem was the microswitch. However the wires from the switch led down to god-knows-where and I thought it better to leave to someone who knows what they're doing.

The guy did test both pump and switches with a multimeter and it proved to be the pump at fault. Is it at all possible to wire it wrongly so it works but won't turn off? Seems unlikely!

There was a thread on here in February 2019 where several people suggested that these pumps failing was a common problem and one or two had installed an isolation switch, including Neckender who provided photographs of what he'd done.

I think installing an isolation switch is a very good idea, to be on the safe side.

So, thank you very much to all of you for your help.

All the best, Leon.

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[SandraL]

The only way the pump should run is if a tap is open turning the microswitch on and thus the pump on.
If the pump runs with all the taps shut you have either a faulty microswitch or a problem in the wiring.

Seems fault first appeared when bathroom tap had been left on, perhaps try to disconnect wiring to this one first, or explore if the new pump was wired incorrectly, ie direct to power supply rather than via tap microswitches.

 

[pappajohn]

The microswitches appear to be okay, but I have to turn off the main control panel to turn the pump off.

Which means you have a failed microswitch (you can't tell by looking at them) or shorted wiring.
The switches need testing with a multimeter set to OHMS. A working switch will show zero when off (tap closed) and infinity when on. (tap open) .
There may even be a relay in the pump wiring triggered by the microswitchs
There will be connectors for the two wires near the tap.

 

[Lenny HB]

The guy did test both pump and switches with a multimeter and it proved to be the pump at fault. Is it at all possible to wire it wrongly so it works but won't turn off? Seems unlikely!

Did he change the switch?
If it's a Riech switch they seem a bit odd, the microswitch is a Normally Open & the tap arm holds the switch lever closed in the off position.
I got fed up with the wires to the switches failing on my van and I got rid of the submersible pump & fitted a Shurflo pressure pump.

 

[autorouter]

To cut a long story short, I got someone to replace the pump but it's permanently on unless I turn the power off. The guy who fitted it wanted to remove all the wood surrounding the water tank (inboard, under the rear bed) to see if there is a "Water Pressure Relief Valve" of some sort. I'm very reluctant to let him do this. Does anyone know if such a thing exists, and why would they hide it away.

To me it sounds like the guy who fitted it thought it was a pressure-switch system. He might have wired it wrong, without using the tap microswitch circuit wires.

Near the pump there will be three wires. A positive supply (from the fusebox or panel switch), a wire to the microswitches, and a wire from the microswitches.

The positive supply connects to the wire to the microswitches (not to the pump). The wire from the microswitches connects to the pump positive.

 

[LeonC]

The only way the pump should run is if a tap is open turning the microswitch on and thus the pump on.
If the pump runs with all the taps shut you have either a faulty microswitch or a problem in the wiring.

Seems fault first appeared when bathroom tap had been left on, perhaps try to disconnect wiring to this one first, or explore if the new pump was wired incorrectly, ie direct to power supply rather than via tap microswitches.

Which means you have a failed microswitch (you can't tell by looking at them) or shorted wiring.
The switches need testing with a multimeter set to OHMS. A working switch will show zero when off (tap closed) and infinity when on. (tap open) .
There may even be a relay in the pump wiring triggered by the microswitchs
There will be connectors for the two wires near the tap.

To me it sounds like the guy who fitted it thought it was a pressure-switch system. He might have wired it wrong, without using the tap microswitch circuit wires.

Near the pump there will be three wires. A positive supply (from the fusebox or panel switch), a wire to the microswitches, and a wire from the microswitches.

The positive supply connects to the wire to the microswitches (not to the pump). The wire from the microswitches connects to the pump positive.

Thanks, guys, I've now got some good suggestions for him to try.

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[LeonC]

Did he change the switch?
If it's a Riech switch they seem a bit odd, the microswitch is a Normally Open & the tap arm holds the switch lever closed in the off position.
I got fed up with the wires to the switches failing on my van and I got rid of the submersible pump & fitted a Shurflo pressure pump.

Hi Lenny, thank you also for feedback. Sounds like this happens quite frequently - why is the Shurflo that much better, and is it relatively easy to fit?

 

[Lenny HB]

Hi Lenny, thank you also for feedback. Sounds like this happens quite frequently - why is the Shurflo that much better, and is it relatively easy to fit?

Pros & Conns with both systems, submersibles tend to be very quiet by comparison, the pressure pumps like the Shurflo give much higher water pressure but are noisy.
Very easy to fit, you do need an isolating switch for the pump. You can even get away with leaving the submersible in the tank and drawing water through it can make the installation simpler.

This was my install.

Lenny's Modding the new Gin Palace

How long did it take you to move the steering wheel, gear knob and pedals. Thinking about doing that to my van so my wife can drive instead of me (y) I would complain you have been sold a duff van, proper German vans always come with the steering wheel on the left & a driver's door.:LOL:

www.motorhomefun.co.uk

 

[LeonC]

Pros & Conns with both systems, submersibles tend to be very quiet by comparison, the pressure pumps like the Shurflo give much higher water pressure but are noisy.
Very easy to fit, you do need an isolating switch for the pump. You can even get away with leaving the submersible in the tank and drawing water through it can make the installation simpler.

This was my install.

Lenny's Modding the new Gin Palace

How long did it take you to move the steering wheel, gear knob and pedals. Thinking about doing that to my van so my wife can drive instead of me (y) I would complain you have been sold a duff van, proper German vans always come with the steering wheel on the left & a driver's door.:LOL:

www.motorhomefun.co.uk

Thanks, Lenny, something for me to consider next time maybe!