Truma Water Heater/Water Pump problem...?

[elusion1]

Hi everyone...

Just joined the foruma dn hoping some of you can shed some light on an issue weve started to have with the water pump.

Weve an Elddis Elusion 4 Berth 2001 - everything was okay (first trip at the weekend) then the pump suddenly stopped working yesterday morning.

A lot to get used to we had a quick once over from the previous owners when we bought it back in August. No hard copy of the manual with it either - I emailed Elddis and they sent me a PDF from 2003 so I'm assuming that manual is still ok for our van.

Anyway - as I say the pump has stopped working/no water and indicator light isn't coming on..it was working fine.

I thought maybe the water barrel was low and the pump had shut off/shorted out..?

Ive read a few forums and this seems common that pumps can go - I'm worried that the pump run indicator isnt illuminating. Previous to this we had water and it was really hot from the hot tap/s so the water heater was working at that time ie Sat night.

Ive checked/tested the pump fuse and the water heater fuses and they are ok.

Ive ordered a water heater fuse for it waiting on it coming. Just in case its went as well.

Was gonna leave it in to a local service centre/dealer but would like to try and sort it myself if I can. Worried what the labour charges might be - its not an Elddis dealer just a general caravan dealer.

Could it be that if the pump is gone then the switch inside wont work at all - and nothing will register? There's nothing at all when turning on the pump switch...? I think we have microswitches on the taps and they are "clicking" when turned on as far as I can hear.

Ive read you can run a 12v battery across the pump terminals to check it works..is this right...? two leads straight off the van battery..?

Any help really appreciated as I'm stumped right now..lol

Thanks a lot

James

 

[ProfJohnL]

Hello elusion1,

First of all welcome to the forum, and I hope that we can help.

Let me assure you that as you have had hot water then that at least means the heater is fine. It will still be full of water as it needs cold water to be pushed in to push hot water out - so unless you have deliberately drained the heater it will still be full of water.

Its worth checking if there is a water pump isolator switch on or near the the 12v distribution controls. Has this been unintentionally turned off?

As the pump fuse is apparently ok, then it must be something to do with the pump control circuit.

If you can carefully arrange a pair of wires, from the battery without shorting them, you could remove the pump from the side of the caravan and test the pump direct from the battery -

If the pump is ok, then you need to identify which type of control system is being used. It will either be a pressure switched system, with a pressure switch fitted inside the caravan close to the cold water inlet, or it will be a switched tap system, where each tap has its own microswitch, and when any tap is opened the switch will feed the pump with power.

It would then be a case of using a multimeter to trace back along the wiring to find where the power is being stopped.

If all the water in your barrel has been used up, then my first comment still holds true - so there should be no danger of the water heater overheating, but if the pump runs there are two main problems.

Most submersible pumps actually rely on having water all around and passing through them to cool the motor. If there is no water there is a danger the motor will overheat, and the heat can distort and compromise the plastic mouldings and precipitate the motors failure.

Another problem can be the motor shaft seals which again rely on water to cool them, and provide some lubrication. Without water the seals can easily overheat and allow water into the motor housing. So try to ensure the pump is never allowed to operate for more than a few seconds except when in water.

When changing the water barrel, always make sure the pump does not create an air lock in the pump's body by unplugging the pump hose from the caravan then drop the pump into the water to allow the water to fill the pump,( only a second or two), then reconnect it to the caravan.

Hope this hekps

 

[elusion1]

Hello elusion1,

First of all welcome to the forum, and I hope that we can help.

Let me assure you that as you have had hot water then that at least means the heater is fine. It will still be full of water as it needs cold water to be pushed in to push hot water out - so unless you have deliberately drained the heater it will still be full of water.

Its worth checking if there is a water pump isolator switch on or near the the 12v distribution controls. Has this been unintentionally turned off?

As the pump fuse is apparently ok, then it must be something to do with the pump control circuit.

If you can carefully arrange a pair of wires, from the battery without shorting them, you could remove the pump from the side of the caravan and test the pump direct from the battery -

If the pump is ok, then you need to identify which type of control system is being used. It will either be a pressure switched system, with a pressure switch fitted inside the caravan close to the cold water inlet, or it will be a switched tap system, where each tap has its own microswitch, and when any tap is opened the switch will feed the pump with power.

It would then be a case of using a multimeter to trace back along the wiring to find where the power is being stopped.

If all the water in your barrel has been used up, then my first comment still holds true - so there should be no danger of the water heater overheating, but if the pump runs there are two main problems.

Most submersible pumps actually rely on having water all around and passing through them to cool the motor. If there is no water there is a danger the motor will overheat, and the heat can distort and compromise the plastic mouldings and precipitate the motors failure.

Another problem can be the motor shaft seals which again rely on water to cool them, and provide some lubrication. Without water the seals can easily overheat and allow water into the motor housing. So try to ensure the pump is never allowed to operate for more than a few seconds except when in water.

When changing the water barrel, always make sure the pump does not create an air lock in the pump's body by unplugging the pump hose from the caravan then drop the pump into the water to allow the water to fill the pump,( only a second or two), then reconnect it to the caravan.

Hope this hekps

Yes thanks a lot Prof John...

I think as far as I can tell its a microswitch system am I right in thinking if the tap "clicks" its a microswitch system...? There are 2 wires running to the vanity unit tap at least, as I checked those yesterday...

I know that the pump was definitely out for more than a few seconds when changing the barrel. It was sitting in the van for the last few weeks so once its submerged it has to stay in water otherwise an air lock coudl occur..? I didnt know that....

I actually tried another pump yesterday from the caravan next to us and still completely nothing no noises etc...no light illuminated on the "pump run" at the control panel. All other electrics etc are working.

The TV/Digibox was on yesterday morning when the pump was activated but no other appliances were on (except for 4 way ext lead with a tablet charger I think) I was reading somewhere about the voltage being affected) Its always worked on the EHU hook up and worked Sat night with 2 TV's and everything else on....

Yes as I was saying the pump fuse isnt gone - neither is the water heater fuse at the fusebox (though I did order a spare - in case) the smaller slow blow fuse at the water heater..

But thats a relief if its not the water heater then thats the problem...

If the pump has gone then the "pump run" light would not work at all..? (Even try to come on) It did flicker then went out and that was that...

I was worried about the water heater but if there's water in there and its ok that great great for a start. I know they arent cheap...

Thanks so far - youve been really helpful...

The van is at my sisters I'll try and get round tomorrow lunchtime and test the pump and see if I can get it working...will I do any harm if I attach the wires to the wrong connections on the pump - I mean are they marked + and - will it still run but just in reverse...?

I'm beginning to think its a wiring problem and not the pump..but see how this goes tomorrow first...

Cheers again for the tips...

James

 

[Hutch]

Elusion, go to basics, sometimes on my Coachman, I put the pump into the barrel and it doesnt run, I have to shake it around a bit and it works, not always a complecated fix,, sometimes simple.
Good luck.
Hutch

 

[ProfJohnL]

Yes thanks a lot Prof John...

I think as far as I can tell its a microswitch system am I right in thinking if the tap "clicks" its a microswitch system...? There are 2 wires running to the vanity unit tap at least, as I checked those yesterday...

I know that the pump was definitely out for more than a few seconds when changing the barrel. It was sitting in the van for the last few weeks so once its submerged it has to stay in water otherwise an air lock coudl occur..? I didnt know that....

I actually tried another pump yesterday from the caravan next to us and still completely nothing no noises etc...no light illuminated on the "pump run" at the control panel. All other electrics etc are working.

The TV/Digibox was on yesterday morning when the pump was activated but no other appliances were on (except for 4 way ext lead with a tablet charger I think) I was reading somewhere about the voltage being affected) Its always worked on the EHU hook up and worked Sat night with 2 TV's and everything else on....

Yes as I was saying the pump fuse isnt gone - neither is the water heater fuse at the fusebox (though I did order a spare - in case) the smaller slow blow fuse at the water heater..

But thats a relief if its not the water heater then thats the problem...

If the pump has gone then the "pump run" light would not work at all..? (Even try to come on) It did flicker then went out and that was that...

I was worried about the water heater but if there's water in there and its ok that great great for a start. I know they arent cheap...

Thanks so far - youve been really helpful...

The van is at my sisters I'll try and get round tomorrow lunchtime and test the pump and see if I can get it working...will I do any harm if I attach the wires to the wrong connections on the pump - I mean are they marked + and - will it still run but just in reverse...?

I'm beginning to think its a wiring problem and not the pump..but see how this goes tomorrow first...

Cheers again for the tips...

James

If you have wires going to every tap, then the caravan was designed to be switched tap system. As such the problem is not likely to be any of the taps, because all the switches are wired in parallel, so if one had failed, the others would still work. Also to answer EH,s point, the pump running light is usually wired in parallel to the pump, so the fact it is not lighting suggests power is not getting to the pump. If the pump had failed the lamp would still normally glow, so no lamp usually means no power. You did mention the lamp flickered but then went out completely. I cannot be certain, but that pattern of failure does suggest a blown fuse or a broken wire. It may be worth checking for any other fuses in the wiring for the pump.

As for testing the pump, it should not matter if you get the wires from the battery the wrong way round, but take care to observe the correct polarity when you connect it or a new pump back into its dedicated wiring.

These pumps can require much higher starting current when they turn on, and some caravan 12V power supplies cannot supply enough power to get them going. This is one reason why having the battery connected as well as can be necessary.

If the pump works when you test it (and I suspect it will), then it's back to using a multimeter and tracing the wires for breaks. As it seems to be loss of power, I would normally begin at the battery and work towards the pump, but with a switched tap system, it might be quicker and easier to work from the pump towards the battery/power supply.

Please be careful, even though the system only uses 12V DC, there is little danger of an electric shock, but with the available current from a battery, there is a real chance of shorted wires over heating and actually causing a fire, so if you are not confident of working with electrics do get proper help.

 

[elusion1]

Hi again Prof John...

Well to add to the mystery its all working now..? LOL

I went over today and had a look - ran two wires from the battery filled a smaller old 2 litre milk carton with water and tried the pump.

As soon as I ran the pump from the battery directly it came on no problem and was quite a powerful spray of water.

So I then tried it back on the van - I did notice the connections are a bit corroded so I will clean them again but connected up and tried a tap with the electric on and it worked! Water out of both taps in the kitchen and bathroom.

Couldn't believe it - I'm thinking now maybe the pump simply ran dry over the weekend and this sounds a bit stupid but I didnt realize the pump and pump run light only actually came on when a tap was turned on..lol seems obvious of course put I was trying the actual pump switch on the control panel and wondering why the pump didnt work.

But checked with the wife and she definitely tried the tap on Sunday and was completely dead.

Could it be that if the pump ran dry then and this has created an airlock in the system or the pump has sort of "auto" shut off...?

I know running the pump dry is not a good idea and could burn it out - it wouldn't have been on for more than a few seconds anyway.

So was careful to only keep the pump out for a few seconds when changing water barrels today and also tried the water heater and theres hot water too...so, so far so good.

One thing I did do just thinking before all this today was to check if the propellar in the pump was turning with a small screwdriver unless it has actually stuck..? Cant say for certain though...

Am thinking of buying a spare pump anyway just in case...

It has left me thinking there might be something up - but could it be as simple as the pump was run dry and this caused the problem...? I'd like to be confident there's nothing else wrong as regards wiring etc...dont want to be left stuck when we are away...

Whats worrying me is I did try another pump on Sunday morning and it never came on either...? Does the pump/system have to "reset" itself in some way...?

A steep learning curve with the caravan right now lol - but once we get into the way of it - happy days.

Cheers for all the help so far..

James

 

[elusion1]

Elusion, go to basics, sometimes on my Coachman, I put the pump into the barrel and it doesnt run, I have to shake it around a bit and it works, not always a complecated fix,, sometimes simple.
Good luck.
Hutch

Cheers Hutch - working today no problems so don't know what might have been up...?

James

 

[Hutch]

James, Glad it's working, aleast for now anyway. I have two spare pumps, a couple of months ago, I cleaned the contacts on the plug into the van and also on the van, all good. My van also has a memory, where by if the van runs out of water you have to turn off the water pump switch and back on again to reactivate the electronics.
Basics though shake the pump.
Hutch.

 

[colin-yorkshire]

hi mate probably something as simple as a stuck pump impeller, as the prof rightly points out it runs on the 12v battery system but only on low amps, the pump requires a higher kick in power to start it and then drops off while running [as does most electrical motors] so it is possible it just would not start the extra kick direct from the battery at full amps jarred it free. had this a couple of times over the years mainly when the pump has been left out of water long enough to dry out but leave residue inside the pump, I found that swinging the pump round to get all the water out after disconnecting helps and when you fill the aqua roll posse the pump up and down in the water a few times to prime it.
oh and carry a spare pump. meanwhile check out all the connections in case there is a poor contact as this will reduce the power available to the pump at start up.

 

[ProfJohnL]

Hi again Prof John...

Well to add to the mystery its all working now..? LOL

I went over today and had a look - ran two wires from the battery filled a smaller old 2 litre milk carton with water and tried the pump.

As soon as I ran the pump from the battery directly it came on no problem and was quite a powerful spray of water.

So I then tried it back on the van - I did notice the connections are a bit corroded so I will clean them again but connected up and tried a tap with the electric on and it worked! Water out of both taps in the kitchen and bathroom.

Couldn't believe it - I'm thinking now maybe the pump simply ran dry over the weekend and this sounds a bit stupid but I didnt realize the pump and pump run light only actually came on when a tap was turned on..lol seems obvious of course put I was trying the actual pump switch on the control panel and wondering why the pump didnt work.

But checked with the wife and she definitely tried the tap on Sunday and was completely dead.

Could it be that if the pump ran dry then and this has created an airlock in the system or the pump has sort of "auto" shut off...?

I know running the pump dry is not a good idea and could burn it out - it wouldn't have been on for more than a few seconds anyway.

So was careful to only keep the pump out for a few seconds when changing water barrels today and also tried the water heater and theres hot water too...so, so far so good.

One thing I did do just thinking before all this today was to check if the propellar in the pump was turning with a small screwdriver unless it has actually stuck..? Cant say for certain though...

Am thinking of buying a spare pump anyway just in case...

It has left me thinking there might be something up - but could it be as simple as the pump was run dry and this caused the problem...? I'd like to be confident there's nothing else wrong as regards wiring etc...dont want to be left stuck when we are away...

Whats worrying me is I did try another pump on Sunday morning and it never came on either...? Does the pump/system have to "reset" itself in some way...?

A steep learning curve with the caravan right now lol - but once we get into the way of it - happy days.

Cheers for all the help so far..

James

I'm glad its working for you, I can't explain the miraculous return to service, unless by moving various things has disturbed a temperamental connection.

I'm and not aware of any submersible pump or system having a thermal reset system, so I doubt that is whats happened. Removing the pump connection may have cleaned a contact, but that does not explain why the indicator light did not work.

As for moving seized impeller, this is possible, but again it does not explain why the replacement pump did not work.

So I'm at a loss to explain precisely what has happened. I still have a strong suspicion you may have an intermittent connection somewhere on the pumps power circuit, which may disconnect any time.

It is a sensible precaution to carry a spare pump.

 

[Hutch]

Hi Prof, the lock out on my water pump is electronic, its the Truma Ultra flow Smart switch.
The following is from Trumas operating manual.
Dry-run protection
Finally in the event that the pump is running but pressure is
below 0.25 bar (3.6 psi) the unit switches off the pump and
locks out in order to protect the pump knowing that the water
supply has run out. After the water container has been refilled
the power should be removed from the system for a period of
approximately three seconds then re-connected. The unit will
then operate normally.

Hutch.

 

[ProfJohnL]

Hello Hutch,

Thank you for the information, Whilst that seems a good idea and will hopefully prevent pump damage if the barrel runs dry, the point I made was there was as far as I am aware no such system available in 2001 which is the date of the OPs caravan. Of course a previous owner may have had on fitted at a later date, but as original not in 2001.

Even with the Truma system if the water runs out it is wise to remove the pump from the caravan and then drop it into the refilled barrel to prevent air locks.

 

[Hutch]

Hi Prof, nine times out of ten, I have to get the wife to do that as I am covered in shower gel. ☺