Help please. Water pump stopped working. (2 Viewers)

[pappajohn]

Pressure switch could be near the pump OR inside the pump itself depending on the pump make.
Either way you have no option but enter the van.
Bottled water perhaps.

 

[MC 55 FUN]

I think this is the pump ?

It looks like this :

There is also something like this alongside the pump.

 

[MC 55 FUN]

Pressure switch could be near the pump OR inside the pump itself depending on the pump make.
Either way you have no option but enter the van.
Bottled water perhaps.

Yes, they are only using water to drink as they have Covid secure access to our bathroom, so bottled water to boil the kettle with will be fine.

I'll try & take a picture of the pump in situ tomorrow & upload it to this thread.

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[two]

If you can get to the pump with a multimeter, check the voltage across its terminals (with the pump switched on at the control panel) using DC range around but over 12V.
If no volts across the pump, look for another device with wires coming from it, near to the pump. It will be on the water pipe and one of its wires will go to the pump. This will be your pressure sensing switch - it turns the pump on when the water pressure drops (when a tap is turned on). Try knocking the sensor - it may be stuck - or adjust it if there is any adjustment.
If 12.5+V across the pump, it's a problem with the pump. It might be jammed - see if you can rotate it. it might have burned-out - remove the wire(s) on one side and test for resistance. if no resistance, get a new pump.

Let us know what you find!

 

[MC 55 FUN]

If you can get to the pump with a multimeter, check the voltage across its terminals (with the pump switched on at the control panel) using DC range around but over 12V.
If no volts across the pump, look for another device with wires coming from it, near to the pump. It will be on the water pipe and one of its wires will go to the pump. This will be your pressure sensing switch - it turns the pump on when the water pressure drops (when a tap is turned on). Try knocking the sensor - it may be stuck - or adjust it if there is any adjustment.
If 12.5+V across the pump, it's a problem with the pump. It might be jammed - see if you can rotate it. it might have burned-out - remove the wire(s) on one side and test for resistance. if no resistance, get a new pump.

Let us know what you find!

Thank you

They are isolating until the 22nd so I can't really get eyes or hands on until after then.

I will of course come back to this thread when i have an answer for the benefit of all those that have helped and others who may have the same issue in the future.

 

[Richard n Ann]

Often near the pump but not always, Richard and Ann any idea?

If it's a whale pump like ours was, the pressure switch is part of the pump a rubber bladder thing inside the pump expands and activates a microswitch

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[Richard n Ann]

I think this is the pump ?

It looks like this :

View attachment 447473
There is also something like this alongside the pump.

View attachment 447474

Yes that's exactly like ours was the pressure switch is part of the pump.

 

[Richard n Ann]

Here's the switch on the top right.

 

[berni109]

This link explains the photo above. Apparently just taking it to bits fixed it. Looks like a stuck pressure switch

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[autorouter]

I made a setup with a submersible pump, a standard in-line light switch, and a cigarette-lighter plug, with a short length of hose and a hozelok adapter at the end. It goes into a standard plastic jerrycan-style water container. Maybe you could rig something up like that for temporary use.

I use it for filling the tank without having to struggle with a heavy container. You could use it for that after all this is over.

 

[MC 55 FUN]

This link explains the photo above. Apparently just taking it to bits fixed it. Looks like a stuck pressure switch

This is excellent - thank you.

Would i need to drain the water tank before removing the pump from the Moho ?

 

[berni109]

"Would i need to drain the water tank" .
Depends where the pump is located in relation to the tank. If its above the level of the tank then no but the few pumps I have seen in situ tend to be at a level with the bottom of the tank. In the latter case unless u want a van full of water drain the tank.

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[MC 55 FUN]

"Would i need to drain the water tank" .
Depends where the pump is located in relation to the tank. If its above the level of the tank then no but the few pumps I have seen in situ tend to be at a level with the bottom of the tank. In the latter case unless u want a van full of water drain the tank.

The water tank is underslung, the pump sits under the half dinette bench seat, so above the tank.

Thank you.

 

[MC 55 FUN]

For Moho owners like me with no knowledge of water pumps i found this informative :

sr_766.50_v1_0512_Layout 1 (whalepumps.com)

 

[MC 55 FUN]

Having now obtained a new multimeter & discovered that there is power to the pump, I now plan to follow the instructions in post #39.

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[Richard n Ann]

Having now obtained a new multimeter & discovered that there is power to the pump, I now plan to follow the instructions in post #39.

Worth a try but it will probably be the motor commutator either dirty or worn out or the brushes worn out. The motor is a sealed unit so you'll never know. I sprayed ours with WD 40 and it worked great for another 2 weeks. Replaced it now with a Sureflow one

 

[MC 55 FUN]

Worth a try but it will probably be the motor commutator either dirty or worn out or the brushes worn out. The motor is a sealed unit so you'll never know. I sprayed ours with WD 40 and it worked great for another 2 weeks. Replaced it now with a Sureflow one

Thank you, I think lack of use probably rules out the worn out theory, I'll find out more tomorrow.

 

[tonyidle]

Assuming the green light normally remains on constantly once the pump is switched on the fault is more likely to be the supply prior to the switch or the switch itself. First check should be the fuse followed by the switch itself (assuming it's a physical switch rather than something you touch on a control panel display).

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[tonyidle]

If the fault is a poor connection the meter will still read 12v. With your meter connected to the pump terminals turn on a tap. If there's a poor connection you will see its effect on the meter.

 

[MC 55 FUN]

Assuming the green light normally remains on constantly once the pump is switched on the fault is more likely to be the supply prior to the switch or the switch itself. First check should be the fuse followed by the switch itself (assuming it's a physical switch rather than something you touch on a control panel display).

The green '' pump running '' light on the control panel does not illuminate when the pump is switched on, there is power at the pump when the pump switch on the control panel is on, the 5a fuse has been checked & replaced multiple times so I'm confident the fuse is fine.

It is a physical mechanical switch.

 

[MC 55 FUN]

Assuming the green light normally remains on constantly once the pump is switched on the fault is more likely to be the supply prior to the switch or the switch itself. First check should be the fuse followed by the switch itself (assuming it's a physical switch rather than something you touch on a control panel display).

With the pump switch in the ''off'' position there is no power to the pump, in the ''on'' position there is power at the pump, albeit with no indicator light, which also seems correct as the pump is silent / not operating, so I'm confident that the physical pump '' on / off '' switch is ok.

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[Richard n Ann]

The green '' pump running '' light on the control panel does not illuminate when the pump is switched on, there is power at the pump when the pump switch on the control panel is on, the 5a fuse has been checked & replaced multiple times so I'm confident the fuse is fine.

It is a physical mechanical switch.

On ours the green 'pump running' LED was on the motor side of the pressure switch, so if it comes on when you open a tap the pressure switch is working (at least in a fashion... The contacts might still be rotted or something)

 

[MC 55 FUN]

On ours the green 'pump running' LED was on the motor side of the pressure switch, so if it comes on when you open a tap the pressure switch is working (at least in a fashion... The contacts might still be rotted or something)

The green indicator light does not illuminate whether the tap(s) are open or closed.

Before the fault manifested itself the green light would illuminate as soon as the pump switch was switched on.

I hope to have the pump removed from situ' tomorrow for an internal investigation

 

[two]

I expect the green light to only come on when the pump is running.
As it seems that your pump has an integral pressure switch, I'd see if I could get to that. The pressure switch controls the pump (and green lamp) and could be stuck in the 'off' position.
If you find some means of adjusting the pressure setting, twiddling that might persuade it to make contact. The pump failing (burning-out) would provide similar symptoms.
Easiest/qickest solution would be to swap the pump out. If you can get the other repaired, at least you'll have a spare.

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[MC 55 FUN]

I expect the green light to only come on when the pump is running.
As it seems that your pump has an integral pressure switch, I'd see if I could get to that. The pressure switch controls the pump (and green lamp) and could be stuck in the 'off' position.
If you find some means of adjusting the pressure setting, twiddling that might persuade it to make contact. The pump failing (burning-out) would provide similar symptoms.
Easiest/qickest solution would be to swap the pump out. If you can get the other repaired, at least you'll have a spare.

Agreed, tomorrow I'll have the pump out of situ & dismantled to see if the instructions in post #39 work or not, at worst I'll need a new pump

 

[andy63]

If you find some means of adjusting the pressure setting,

All the surflow type pumps I've looked at have an adjustment on the so called pressure switch..it simply alters the distance of travel of a plunger and hence the pump cycling time..it has negligible effect on the actual pressure..
The pressure the pumps run at is governed by whatever spring they have fitted..there is no means of altering their pressure
Andy

 

[MC 55 FUN]

All the surflow type pumps I've looked at have an adjustment on the so called pressure switch..it simply alters the distance of travel of a plunger and hence the pump cycling time..it has negligible effect on the actual pressure..
The pressure the pumps run at is governed by whatever spring they have fitted..there is no means of altering their pressure
Andy

This is a whale pump.

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[andy63]

This is a whale pump.

I should read through the thread before I jump in..
Apologies
Andy

 

[tonyidle]

With the pump switch in the ''off'' position there is no power to the pump, in the ''on'' position there is power at the pump, albeit with no indicator light, which also seems correct as the pump is silent / not operating, so I'm confident that the physical pump '' on / off '' switch is ok.

On that basis if it flickers it's the pressure switch.

 

[MC 55 FUN]

Slight delay due to inclement weather, pump removed from the Moho earlier, taken apart & tested as per the informative video in post #39, a very gentle, cautious fiddle with the microswitch, spring, plunger & diaphragm & I'm pleasantly surprised that the pump works fine after repetitive testing ( on the kitchen worktop ) . .

I hope that's the electrical side, and to me the easiest part, of the pump debacle ruled out as a cause, no doubt the true test will be when it's all back together in situ'.

To be continued, with hopefully a no cost, happy ending.

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