Water pump not working….🤷🏼‍♂️

[Where to next?]

Hi all. The water pump in our Dethleffs Trend was noisy when operating for a couple of weeks and has now totally stopped working. I concluded that it was on its last legs and has now broken, so I purchased the exact same part (Comet Lux Plus) and set about replacing it myself. New pump is now installed, and the tank half filled….. but, the taps/shower/toilet flush aren’t working and the usual noise of the water pump when operating isn’t happening. I’ve checked the 12v circuit is operational and that the fuse box hasn’t tripped but am now wondering what to check next. Any ideas from those of you more technically minded than me….? Thanks in advance.

 

[Bessy765]

Do you have micro switches in the taps or an inline pressure switch?

 

[Where to next?]

Microswitches in the taps. They are all silent when I turn them on unlike the usual faint buzz.

 

[pappajohn]

Have you checked fuses with a multimeter.
A visual check often isn't good enough.
If the old pump seized it will have blown the fuse

 

[raysalaugh]

So you say you've checked the 12 volt circuit and that's ok, is it a submersible pump or a surface pump?.
Check for voltage at the pump then if none work backwards, make sure you activate a tap when checking.

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[Landy Andy]

Your old failed pump may have blown the fuse in the system.

Do you have 12v at the pump pos and neg?
If not can you run a temporary supply just to test it, with a tap open?
If the pump is getting 12v, with a tap open can you feel the pump and is it humming. If it is give it a good shake and knock it on the side of the tank whilst it’s submerged. It may just have an air lock.

 

[Where to next?]

Have you checked fuses with a multimeter.
A visual check often isn't good enough.
If the old pump seized it will have blown the fuse

Ok. Thanks for that. I’ll check - every day is a school day!

 

[Where to next?]

So you say you've checked the 12 volt circuit and that's ok, is it a submersible pump or a surface pump?.
Check for voltage at the pump then if none work backwards, make sure you activate a tap when checking.

Thanks. Submersible pump. Think I need to invest some time in getting a multimeter and learning how to use it!

 

[Where to next?]

Your old failed pump may have blown the fuse in the system.

Do you have 12v at the pump pos and neg?
If not can you run a temporary supply just to test it, with a tap open?
If the pump is getting 12v, with a tap open can you feel the pump and is it humming. If it is give it a good shake and knock it on the side of the tank whilst it’s submerged. It may just have an air lock.

Cheers. Haven’t done any 12v tests other than checking the lights are working. Based on how things normally work, I am confident that there’s no power to the taps as they’re not humming. Don’t think it’s an airlock. Think I’ll focus on finding/checking the fuses next.

 

[Where to next?]

Quick update. There are faint single clicks when I turn the taps on and off. I.e. it sounds like the microswitches are working/have power?

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[Brains]

Is the pump running.

The simple way to find out (without a multi meter) is to remove the outlet hose and then ask your dearly beloved to turn on a tap.

If a fountain of water emerges, the pump is working, but you have a plumbing issue.
If nothing happens, you have an electrical issue.

 

[Where to next?]

Wow. You lot are brilliant. I’m always keen to have a go but generally have no idea about how things work. Still, with the help of your responses, I’ve found where the fuses are located, removed the water pump fuse, replaced it with a spare to see if it had blown or not….. and hey presto….the pump is working and the taps have flowing water once again! Just got to buy a replacement 5 amp fuse. Many thanks again for your support and guidance!

 

[Where to next?]

Have you checked fuses with a multimeter.
A visual check often isn't good enough.
If the old pump seized it will have blown the fuse

Spot on that man! Cheers!

 

[herald_400rl]

Thanks. Submersible pump. Think I need to invest some time in getting a multimeter and learning how to use it!

Aldi sometimes have then in for a fiver. They're basic but do continuity (what you need in this case) and AC/DC voltage up to what "we" need them for.

 

[BouncyBoatFolk]

It's worth having a set of replacement fuses on board, and if buying for the first time it's even more worthwhile looking at LED glow blow fuses, [ illuminate when blown] or resettable fuses, that one's a bit more obvious. you may also wish to consider some maxi, midi , and any other fuses used it's such a simple but essential bit of kit that not having one can soon lead to a disappointing trip.
Mike.

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[Landy Andy]

Quick update. There are faint single clicks when I turn the taps on and off. I.e. it sounds like the microswitches are working/have power?

The faint click, is just the switch moving. It is not a sign of voltage.

I would very much recommend you get a multimeter, they are of great use in a motorhome and although you don’t understand what it can do, it will help us here diagnose issues, whilst you learn about your multimeter and your van.

 

[pappajohn]

Buy a box of assorted rating fuses. They can, and do, blow at any time.
They aren't expensive! but try to avoid Chinese makes.....I know that isn't easy but they usually are of dubious quality.

 

[Vikdikdok]

Quite often a fuse will visually look ok, it’s not until you do a continuity test with a multi meter that fuse defects show up

 

[Where to next?]

Buy a box of assorted rating fuses. They can, and do, blow at any time.
They aren't expensive! but try to avoid Chinese makes.....I know that isn't easy but they usually are of dubious quality.

That’s exactly what I’ve done thanks. Just awaiting Amazon delivery of an assortment of ratings! And once I’ve got my multi meter I’ll be fully armed to tackle the next problem!