Life is never boring. Yesterday came back to the van to see water coing out onto the floor from the HWS. Funnily enough the HWS and the mains water have been switched off for the last few days whilst I was away.
The question is; How do I turn off the water to the HWS so it doesnt leak out but still have water to sink tap and even water for a cold shower.
It is a Dometic HWS located in a rather awkward position at the bottom of a cupboard and under the bed. If the bottom of the cupboard is lifted up the top of the hws is visible.
Thanks for any assistance.
Possum3 said
09:26 AM Dec 27, 2019
Truma have a bad habit of splitting their S/S tanks. Check whether yours has split tank. If so replacement required - if not all plumbing bits from Caravans plus. www.caravansplus.com.au/appliances/hot-water-systems/truma-parts/ Imperative tha water is stopped from leaking ASAP - Ply flooring will rot out in no time flat.
-- Edited by Possum3 on Friday 27th of December 2019 09:26:21 AM
Possum3 said
09:41 AM Dec 27, 2019
Re read you question; If you wish to isolate water heater there may be a stopc0ck (Tap) on your water entry line. As all caravans have their own unique plumbing it will be trial and error to determine whether you can isolate heater and still have water delivered to other faucets.
-- Edited by Possum3 on Friday 27th of December 2019 09:42:21 AM
-- Edited by Possum3 on Friday 27th of December 2019 09:43:15 AM
DMaxer said
12:04 PM Dec 27, 2019
Thanks for the help Possum. I have enlisted the help of someone who foolishly was sitting outside their caravan doing nothing, so we will be "going in" after lunch.
Dougwe said
03:03 PM Dec 27, 2019
Oh no, I just visualised two bums up in air checking the hot water heater. Hope that vision goes quickly.
Tony Bev said
09:16 PM Dec 27, 2019
Hi DMaxer I also have the Truma HWS, and I recently had the trauma of replacing the 240 volt element
The pipes were John Guest 12 mm
If you can see/feel the pump (on my HWS), the pipe from the pump met a "T" Piece The water for the cold water taps went straight through The water to the HWS diverted towards the boiler
If you can remove the 12 mm plastic pipe at the "T" Piece, (the one going towards the boiler), you should be able to plug in a short piece of pipe with a John Guest one way valve at the end
Below is a picture of the John Guest one way valve, which sould be obtainable from just about any caravan place for around $20
This should allow you to keep using the cold water taps, until you have repaired whatever the fault is
Hope that this info is useful to you
DMaxer said
07:26 AM Dec 28, 2019
Thanks for your helpful advice. I was lucky enough to get the services of a plumber and it is a dud fitting. He is coming back on Monday morning to fit a new part. I am glad it was not the HWS that was cactus.
This is the second fitting I have had replaced on the HWS in the last 6 months. Whilst I have no issues with the HWS, why do they use these crappy fittings on caravans. Window latches, door locks, cupboard locks are all el cheapos.
I guess they want us to have a constant source of whinging material. If that is the case, then it has worked well.
Thanks everyone and stay posted for my next drama.
kesa32 said
08:35 AM Dec 28, 2019
Hi Dmaxer , good to hear it's just a fitting leaking , do you have a pressure reduction valve fitted in the van ? ( lm guessing you already have one )
Hopefully you don't have any more issues mate
DMaxer said
11:22 AM Dec 28, 2019
No Kesa I don't have one fitted. I only ever turn the mains tap on about a quarter of a turn. I think I will now get one.
Funnily enough, the mains water was turned off when it leaked so it was only what was in the hose.
Possum3 said
12:55 PM Dec 28, 2019
DMaxer - Back to school for you. Remember Pascal's Law (Principle) Pascal's law (also Pascal's principle or the principle of transmission of fluid-pressure) is a principle in fluid mechanics that states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere.
As long as the tap valve is open the pressure on your system is same as if fully opened (of water source).
DMaxer said
01:56 PM Dec 28, 2019
You are absolutely right Possum. Didn't Pascal have a triangle for use in maths?
Mike Harding said
02:40 PM Dec 28, 2019
Possum3 wrote:
a principle in fluid mechanics that states that a pressure change occurring anywhere in a confined incompressible fluid
No such animal... ask a black hole.... :)
Dougwe said
03:59 PM Dec 28, 2019
Possum3 wrote:
DMaxer - Back to school for you. Remember Pascal's Law (Principle) Pascal's law (also Pascal's principle or the principle of transmission of fluid-pressure) is a principle in fluid mechanics that states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. As long as the tap valve is open the pressure on your system is same as if fully opened (of water source).
Struth Possum, I'm totally confused with all that. I think I will have to go consult with Prof Julius Sumner Miller on that. Bugga, can't. He has driven on ahead.
Possum3 said
05:16 PM Dec 28, 2019
Mike Harding wrote:
Possum3 wrote:
a principle in fluid mechanics that states that a pressure change occurring anywhere in a confined incompressible fluid
No such animal... ask a black hole.... :)
The critical differential being confined - a black hole is a region of space-time exhibiting gravitational acceleration so strong that nothingno particles or even electromagnetic radiation such as lightcan escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform space-time to form a black hole.
Chief Doug; You can't take the smart arse teacher out of an old engineer.
DMaxer said
08:45 PM Dec 28, 2019
Didn't Prof Julius Sumner Miller have something to do with Cadbury's chocolates Doug?
Why is it so.
Snail said
09:50 PM Dec 28, 2019
I had a laugh when i read Pascal's principle 1653 that was drum into me when i was a Lad.
Dougwe said
07:21 AM Dec 29, 2019
DMaxer wrote:
Didn't Prof Julius Sumner Miller have something to do with Cadbury's chocolates Doug?
Why is it so.
I think he did BigD. "A glass and a half of milk in every block" Me thinks anyway.
Me also thinks BigD you taken your topic slightly off topic :) or was that me? Nah! I don't do that
DMaxer said
09:28 AM Dec 29, 2019
I'll tell you what Doug, there was more than a glass and a half of water coming out of the HWS when the fitting called it a day and went to that big bathroom in the sky.
I didn't need Julius to point that out to me although I did think "why is it so", but in much stronger terms and language!
-- Edited by DMaxer on Sunday 29th of December 2019 09:29:14 AM
DMaxer said
08:21 AM Dec 31, 2019
Problem solved. Looked everywhere for a new fitting but the only person who stocked them around here was closed until Jan 6th. On an off chance I rang his after hours number and guess what, he came into town, opened his shop and sold me the fitting. He told me if there was any other issues just give him a call, wished me a happy new year and closed up again.
How good was that from him.
Karma will be good to him.
Dougwe said
08:25 AM Dec 31, 2019
Well done BigD. A good news story for sure.
Only thing is though, he doesn't know you very well
Life is never boring. Yesterday came back to the van to see water coing out onto the floor from the HWS. Funnily enough the HWS and the mains water have been switched off for the last few days whilst I was away.
The question is; How do I turn off the water to the HWS so it doesnt leak out but still have water to sink tap and even water for a cold shower.
It is a Dometic HWS located in a rather awkward position at the bottom of a cupboard and under the bed. If the bottom of the cupboard is lifted up the top of the hws is visible.
Thanks for any assistance.
Truma have a bad habit of splitting their S/S tanks. Check whether yours has split tank. If so replacement required - if not all plumbing bits from Caravans plus. www.caravansplus.com.au/appliances/hot-water-systems/truma-parts/
Imperative tha water is stopped from leaking ASAP - Ply flooring will rot out in no time flat.
-- Edited by Possum3 on Friday 27th of December 2019 09:26:21 AM
Re read you question; If you wish to isolate water heater there may be a stopc0ck (Tap) on your water entry line. As all caravans have their own unique plumbing it will be trial and error to determine whether you can isolate heater and still have water delivered to other faucets.
-- Edited by Possum3 on Friday 27th of December 2019 09:42:21 AM
-- Edited by Possum3 on Friday 27th of December 2019 09:43:15 AM
Thanks for the help Possum. I have enlisted the help of someone who foolishly was sitting outside their caravan doing nothing, so we will be "going in" after lunch.
Oh no, I just visualised two bums up in air checking the hot water heater. Hope that vision goes quickly.
Hi DMaxer
I also have the Truma HWS, and I recently had the trauma of replacing the 240 volt element
The pipes were John Guest 12 mm
If you can see/feel the pump (on my HWS), the pipe from the pump met a "T" Piece
The water for the cold water taps went straight through
The water to the HWS diverted towards the boiler
If you can remove the 12 mm plastic pipe at the "T" Piece, (the one going towards the boiler), you should be able to plug in a short piece of pipe with a John Guest one way valve at the end
Below is a picture of the John Guest one way valve, which sould be obtainable from just about any caravan place for around $20
This should allow you to keep using the cold water taps, until you have repaired whatever the fault is
Hope that this info is useful to you
Thanks for your helpful advice. I was lucky enough to get the services of a plumber and it is a dud fitting. He is coming back on Monday morning to fit a new part. I am glad it was not the HWS that was cactus.
This is the second fitting I have had replaced on the HWS in the last 6 months. Whilst I have no issues with the HWS, why do they use these crappy fittings on caravans. Window latches, door locks, cupboard locks are all el cheapos.
I guess they want us to have a constant source of whinging material. If that is the case, then it has worked well.
Thanks everyone and stay posted for my next drama.
Hopefully you don't have any more issues mate
No Kesa I don't have one fitted. I only ever turn the mains tap on about a quarter of a turn. I think I will now get one.
Funnily enough, the mains water was turned off when it leaked so it was only what was in the hose.
As long as the tap valve is open the pressure on your system is same as if fully opened (of water source).
You are absolutely right Possum. Didn't Pascal have a triangle for use in maths?
No such animal... ask a black hole.... :)
Struth Possum, I'm totally confused with all that. I think I will have to go consult with Prof Julius Sumner Miller on that. Bugga, can't. He has driven on ahead.
The critical differential being confined - a black hole is a region of space-time exhibiting gravitational acceleration so strong that nothingno particles or even electromagnetic radiation such as lightcan escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform space-time to form a black hole.
Chief Doug; You can't take the smart arse teacher out of an old engineer.
Didn't Prof Julius Sumner Miller have something to do with Cadbury's chocolates Doug?
Why is it so.
I had a laugh when i read Pascal's principle 1653 that was drum into me when i was a Lad.
I think he did BigD. "A glass and a half of milk in every block" Me thinks anyway.
Me also thinks BigD you taken your topic slightly off topic :) or was that me? Nah! I don't do that

I'll tell you what Doug, there was more than a glass and a half of water coming out of the HWS when the fitting called it a day and went to that big bathroom in the sky.
I didn't need Julius to point that out to me although I did think "why is it so", but in much stronger terms and language!
-- Edited by DMaxer on Sunday 29th of December 2019 09:29:14 AM
Well done BigD. A good news story for sure.
Only thing is though, he doesn't know you very well




Hot showers now, ripper Rita.
Keep Safe on the roads and out there.