Airing out clean water tank

[fcarbon]

Hello,

(New to the forum - couldn’t find the answer, pardon me if it exists somewhere.)
Anyone actually opens the clean water tank “cleaning acces cover” to let the clean water tank dry out while empty (as the owner’s manual suggests)?
I tried but couldn’t get the cap moving ...

Thank you!

 

[Grand Tourismo]

Hello,

(New to the forum - couldn’t find the answer, pardon me if it exists somewhere.)
Anyone actually opens the clean water tank “cleaning acces cover” to let the clean water tank dry out while empty (as the owner’s manual suggests)?
I tried but couldn’t get the cap moving ...

Thank you!

Hello FCarbon and welcome along...yes I removed mine just about a week ago and drained out the water left inside. It was very "stuck" in place, a friend advised using warmth to help move it (they use a bed water-bottle of hot water placed on the cap for 5-10 mins)...I didn't have the patience so I put a thick cloth over the top and used the jaws of a pipe grip placed into the little recesses to provide extra leverage like a handle. It really wasn't stuck at all, just a little too much for my fingers to twist.

P.S. if you drain down the water tank you should try to isolate the water pump system just in case you accidentally switch one of the taps on. You can remove the fuse or use a rubber band on the tap to secure it in the closed position...or you can make an isolation switch. Search " Water pump isolator" on here to find out how...

 

[Grand Tourismo]

The next thing I want to work out is what I can use to cover the opening over when driving around, something breathable but also protective

 

[Blackrat]

P.S. if you drain down the water tank you should try to isolate the water pump system just in case you accidentally switch one of the taps on. You can remove the fuse or use a rubber band on the tap to secure it in the closed position...or you can make an isolation switch. Search " Water pump isolator" on here to find out how...

We were caravanners for many years before getting our MP.
The advice is that you should drain the system over winter to avoid frost damage.
Over the winter taps should never be left in the closed position because even the smallest amount of water left in the system could freeze. It will then expand and cause the tap or pipes to split.
Hence the advice to remove the fuse to the water pump and leave the tap open over the winter.

 

[Grand Tourismo]

We were caravanners for many years before getting our MP.
The advice is that you should drain the system over winter to avoid frost damage.
Over the winter taps should never be left in the closed position because even the smallest amount of water left in the system could freeze. It will then expand and cause the tap or pipes to split.
Hence the advice to remove the fuse to the water pump and leave the tap open over the winter.

Good advice! - I also noticed that when draining down I opened the tap and there was a fair amount of water air trapped in the system...not nice to have that in there.

What did you flush the tank with Blackrat?

 

[Blackrat]

All I’ve ever done is drain the system down at the end of the season and leave the taps in the open position to avoid frost damage. On the MP this means removing the fuse to stop the pump from running . Most caravans/motor homes have a switch for this purpose.
At the start of the season I use Milton or similar to sterilise the tank and pipes. Put a solution into the tank and pump it through the system, then flush a couple of times with fresh water.

 

[Samebutdifferent]

First off a warm to @fcarbon.

I don't have a MP yet! but am familiar with van fresh water tanks.
The usual solution to removing the tank cap is to make a tool from a wooden batten or such so you can get more purchase, as mentioned by @Grand Tourismo above you just need more leverage.

I'm not sure why you'd want to open the tank to let it dry out, the whole system, pipes and taps etc needs to be dry to stop any bacterial growth. I doubt removing the tank cap would achieve that.

All the advice regarding overwintering to avoid frost damage is pertinent but I feel the stoping bacterial growth is more to the point.

Some use citric acid to clean their water systems, available cheaply in bulk on eBay. A motorhome compatible product is probably the best and Puriclean Tabs is what I use. Milton will probably be ok in simple systems like on the MP, but it contains chemicals that could possibly damage things like on board boilers the some vans have.

I clean my tank once or twice a year with Puriclean, I don't 'air' the tank but drain to prevent frost damage. I'll happily clean my teeth, boil the tank water for cups of tea, coffee, spuds or pasta. But if I want a drink, that will be a beer from in the fridge, failing that some mineral water

 

[fcarbon]

The next thing I want to work out is what I can use to cover the opening over when driving around, something breathable but also protective

Thank you Grand T., Blackrat and Samebutdiff. for your interesting comments!
Grant T., would just putting the bottom shelf back provide sufficient cover/protection?

 

[Grand Tourismo]

Thank you Grand T., Blackrat and Samebutdiff. for your interesting comments!
Grant T., would just putting the bottom shelf back provide sufficient cover/protection?

It does offer some cover but there is a big hole in the centre of the shelf for your finger to go through, and from memory this coincidentally aligns with the tank inspection hatch...I was thinking of using some stocking material and an elastic band.

One thing I would say though, there is a gap between the tank front and the cabinet just big enough for your mobile phone to fit down. If you plan to use a torch in that cabinet whilst you mess about with the tank use a big round one, not your phone...took me ages to recover my phone out of the gap!

 

[fcarbon]

Aha that is indeed some advice to heed!

The dealer also suggested to leave the grey water tank emptying-latch open while not in use ... does this sound as sound advice?

 

[fcarbon]

One thing I would say though, there is a gap between the tank front and the cabinet just big enough for your mobile phone to fit down. If you plan to use a torch in that cabinet whilst you mess about with the tank use a big round one, not your phone...took me ages to recover my phone out of the gap!

Just saw the gap you are referring to ... how on earth did you ever get your phone out!?

 

[Grand Tourismo]

Just saw the gap you are referring to ... how on earth did you ever get your phone out!?

I slid it down to the end of the cupboard near the tailgate and fished it out of the little louvred vent thing...was a big faff!

 

[fcarbon]

I wonder it might be true that when unplugging the water pump fuse (n°2) the electronics of the 2020 (300d) model act weirdly like not starting the Advanced Control (blanc screen OR nothing happens when pushing the Adv. Contr. Icon) AND a mechanical rattling noise in the sound system (whether radio or media player).

I don’t know that there is a correlation here but I unplugged the fuse to empty the water tank and temporarily open the faucet. I left it unplugged while driving and the problems occured. On the way back from our destination where we took a two hour walk: same thing. Only then did I think about the fuse, put it back in and everything was fine again, sound and Advanced Control screen both OK ...

Perhaps not such a good idea to leave the fuse out in the 2020 model?

 

[fcarbon]

I wonder it might be true that when unplugging the water pump fuse (n°2) the electronics of the 2020 (300d) model act weirdly like not starting the Advanced Control (blanc screen OR nothing happens when pushing the Adv. Contr. Icon) AND a mechanical rattling noise in the sound system (whether radio or media player).

I don’t know that there is a correlation here but I unplugged the fuse to empty the water tank and temporarily open the faucet. I left it unplugged while driving and the problems occured. On the way back from our destination where we took a two hour walk: same thing. Only then did I think about the fuse, put it back in and everything was fine again, sound and Advanced Control screen both OK ...

Perhaps not such a good idea to leave the fuse out in the 2020 model?

I just realize I did reset the system on the way back and perhaps this only kicked in (some items can’t be reset during driving) when I restarted the car AFTER plugging back in the fuse ... So I’ll have to try unplugging the fuse tomorrow and see what happens ...

 

[fcarbon]

OK so I went back to the beloved 2020 Marco Polo. I did the following:
1. (with fuse nº2 installed) Advanced Control working fine and sound OK
2. Removed fuse nº2: Advanced Control not working: blank screen. (At least the water pump and interior lighting were disabled as well.)
3. Re-installed fuse nº2: Advanced Control working fine.

All this seems to be confirmed by my new user's manual (see picture, not yet available online I believe):
- Fuse nº2 refers to both "Multi-media system 2" and "Interior Lighting". (Also disabling the water pump.)
- The manual still advises to remove the fuse and open the faucet while emptying the clean water tank, but also to close the faucet and re-install the fuse after emptying (see picture).

I think it is safe to assume that since the introduction of the Advanced Control (MBAC) it is not wise to keep fuse nº2 removed (or install the "water pump isolator" mentioned on this forum ...?).

Perhaps I should start a new thread on this subject as a warning to new Marco Polo owners?

[The strange static rattling interference in the sound system experienced yesterday as well, I could not reproduce by removing the fuse; but I was driving yesterday and today only trying things out with both engine running stationary and not running. I assume another electric system engaged while driving in combination with the removed fuse nº2, might have caused this sound interference? I am not an (electrical) engineer, so please correct met if all this doesn't make any sense at all ;-)]

 

[Samebutdifferent]

Very strange, the fresh water pump is part of the habitation unit and as such should be connected to the habitation battery. Am I right in thinking from your findings it's actually connected to the starter battery?

 

[fcarbon]

Very strange, the fresh water pump is part of the habitation unit and as such should be connected to the habitation battery. Am I right in thinking from your findings it's actually connected to the starter battery?

Perhaps from the central control screen ónly the Advanced Control interface is part of the habitation battery since all other applications work fine (Navigation, A/C etc.)? This would make sense. (So yes the water pump seems connected to the habitation battery.)

 

[Grand Tourismo]

Very strange, the fresh water pump is part of the habitation unit and as such should be connected to the habitation battery. Am I right in thinking from your findings it's actually connected to the starter battery?

I think the new systems both somehow integrate as there is no separate control unit for the habitation and roof side now...it is all included within the new MBAC (posh dash telly) display thing.
Still you need to be able to isolate the water pump on the habitation side to protect from dry running...I wonder what MB would make of that?

 

[fcarbon]

I think the new systems both somehow integrate as there is no separate control unit for the habitation and roof side now...it is all included within the new MBAC (posh dash telly) display thing.
Still you need to be able to isolate the water pump on the habitation side to protect from dry running...I wonder what MB would make of that?

Well they still advise to remove the fuse and open the faucet while emptying the clean water tank, but also to close the faucet and re-install the fuse after emptying. I guess it's back to the simplicity of the rubber band ...

 

[Grand Tourismo]

Well they still advise to remove the fuse and open the faucet while emptying the clean water tank, but also to close the faucet and re-install the fuse after emptying. I guess it's back to the simplicity of the rubber band ...

Looks like the only easy solution for now...although the switch Douglas and I fitted simply isolates the pump (it puts a breaker in the pump feed). Maybe you can do the same without disturbing the rest of the circuit to the MBAC unit? Your call though, I can't see your system and I do not know enough.