Apart from the energy required to achieve and maintain that temperature there are legal requirements for domestic & commercial Hot Water Systems :
The Plumbing Code of Australia and relevant Australian Standards set strict temperature requirements for all hot water systems.
Plumbers must set storage temperatures to at least 60°C to control the growth of Legionella bacteria. For personal hygiene useslike showers and bathsthey must cap the delivery temperature at 50°C to prevent scalding.
In commercial settings such as kitchens, plumbers may set delivery temperatures higher, up to 70°C, for sanitary purposes.
Always include an approved tempering valve in new installations. Make sure that hot water doesnt exceed 50°C at outlets used for personal washing.
-- Edited by kgarnett on Thursday 26th of March 2026 05:18:28 PM
I have a Truma in my motorhome and it has the option of either 60 or 70 deg C.
I always make a point of rinsing the shampoo out of my hair first, just in case I run out.
I spent 3 months in Germany with my relatives. Their HWS is a heat pump system in the basement. It has 3 settings, 45, 50 & 55. They have it set on 45. The bathrooms are 2 floors above, never once was the hot water not hot enough. I always needed to add cold water. Ambient outside temperature was typically -5 to 0 degrees while I was there December to February.
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50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
I learnt quite a few cold weather skills while there. I have been there many times before but only once in winter before briefly.
The central heating system is always left on level 1 at a minimum over winter so pipes don't freeze.
Once I tried to clean the car windscreen with water. It didn't matter how much water I put on the windscreen, it just all froze into solid ice. Which was actually impossible to scrape off.
If I had simply scraped it off initially with the windscreen ice scraping tool, it would have been easy, like I had done previously.
One lives & learns new skills in a cold environment. We were grateful that even though it was so cold, that we only had snow, but no rain! The rain freezes on the roads which turns them into a skating surface.
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I Have done this ...and with common sense works well...just remove the tempering valve. The HWS has a thermostat set at 65 degrees so all the fearmongering about getting scalded is just that. The upside to this is that less hot is used in the shower and 2 people can have two decent but shortish showers without running out of hot.
Find out how to do it ...enough info on the net...but is a simple easy job.
Cheers Keith
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The matter is that since the hws water is so tepid, only a relatively small amount
of cold is needed to achieve a nice temp for a shower. Therefore a relatively large
amount of hws content is used.
I don't think I have a tempering valve - in fact that sounds far too technical for
Jayco anyway. I'm the tempering valve at the flick mixer. 60 or 70 deg would be
great. My hws at home is set at 72 which is the min temp to destroy leigioniers
bacteria.
Who knows how to modify/replace/obtain a suitable thermostat?
Peter - what's a JG pipe? (I just use a cut down softdrink bottle!).
I expect that the HWS will be set to 60C or over. This is required to kill legionnaire bacteria (and others).
That would be pretty normal. Mine at home is set to 65 from memory. But it is tempered to about 50 at the taps. When the heater was replaced (about 10 years ago) I remember being disappointed in the temperature, particularly at the kitchen sink. The plumber told me at the time that any new installations were mandated to be fitted with a tempering valve.
Now that I have been using it for years I am used to it. I can just hold my hands under the hot tap while washing. I have grandchildren who are just managing to reach the taps themselves. I would hate to hear their screams as they unknowingly got scalded. But of course the main reason is for babies in the bath who may accidentally flip the tap on.
When I go to the van which has no such tempering valve I curse when I forget and my hands get scalded a bit.
The matter is that since the hws water is so tepid, only a relatively small amount of cold is needed to achieve a nice temp for a shower. Therefore a relatively large amount of hws content is used.
I don't think I have a tempering valve - in fact that sounds far too technical for Jayco anyway. I'm the tempering valve at the flick mixer. 60 or 70 deg would be great. My hws at home is set at 72 which is the min temp to destroy leigioniers bacteria.
Who knows how to modify/replace/obtain a suitable thermostat?
Peter - what's a JG pipe? (I just use a cut down softdrink bottle!).
B
Thanks to the posters.
My van is a 2017 build. It has a tempering valve and I know other Jayco owners with 2017 models that have tempering valves. I believe earlier built models also have tempering valves. My tempering valve is under the floor near the HWS. My tempering valve is a white colour.
My van is a 2017 build. It has a tempering valve and I know other Jayco owners with 2017 models that have tempering valves. I believe earlier built models also have tempering valves. My tempering valve is under the floor near the HWS. My tempering valve is a white colour.
Mine is an Early 2018 Jayco.
The tempering valve is ...as you said ...white and is a bit like a " T "..ie...pipes at each end and 1 on each side..and have both cold and hot hooked to it. Not really hard to figure out how to delete ...plenty of info on the net tho.
Cheers Keith
__________________
Nuthin is ever the same once I have owned it ......
The matter is that since the hws water is so tepid, only a relatively small amount of cold is needed to achieve a nice temp for a shower. Therefore a relatively large amount of hws content is used.
I don't think I have a tempering valve - in fact that sounds far too technical for Jayco anyway. I'm the tempering valve at the flick mixer. 60 or 70 deg would be great. My hws at home is set at 72 which is the min temp to destroy leigioniers bacteria.
Who knows how to modify/replace/obtain a suitable thermostat?
Peter - what's a JG pipe? (I just use a cut down softdrink bottle!).
B
Thanks to the posters.
My van is a 2017 build. It has a tempering valve and I know other Jayco owners with 2017 models that have tempering valves. I believe earlier built models also have tempering valves. My tempering valve is under the floor near the HWS. My tempering valve is a white colour.
Unless I missed something I have noticed no one answered your question "what is JG pipe?"
JG Pipe is John Guest pipes and fittings. Used in caravans etc due to their ease and light weight.
OH! I haven't had a Temp valve since 2017 when I replaced an instant hot water system with a Suburban and so far to this day has worked perfectly with my Suburban HWS. I live in my aluminium tent full time.
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If a tempering valve is designed to reduce the temperature of the hot water to
something more amenable, why then is the temp IN the hws so temperate?
Ideally the water in the hws would be, say, 80+ to allow for plenty of cold to
be added and thereby contributing to the volume of tepid water available for
a decent shower, or at least 2 showers.
I have to turn the gas on immediately the bride begins to shower so that it
doesn't "go cold !!!!!!!!" before she's finished.
Don't forget that a HWS in a van is probably about 10% the size of one at home. Are you sure the storage temperature is so low? How did you measure it?
Maybe your bride has not "tempered" her usage from what she does at home and showers with a decent stream. Making a couple of assumptions ....... 20L hot water stored at 65 degrees, cold water temperature about 20 degrees, shower head is limited to say 6 litres per minute. That would give about 8 minutes of showering at 40 degrees. Or if the shower head is a 3 star 9 litres per minute one, that would give 5 minutes of showering.
-- Edited by Are We Lost on Monday 30th of March 2026 10:45:47 AM
That's a very pertinent point that you have raised - what if the water is already tempered at the tap. !!!!
Trouble is, others say temp in hws is set at 50, and I measure at tap 50.
Never thought of that. So now I have to get under the damn thing and screw about. I suppose that I look for a 2-in and one out somewhere not too far from the hws.
As far as water volume usage - thats very pertinent also. See, we have had a few vans and we have always been able to have a shower each by turning water off between soaping and rinsing.
It's a hell of a quandary for one that has spent many years in quality control - amongst other things, but trouble is now I'm running at best on common sense because I won't recognise the devices other than by guessing their purpose based on location.
here we go. (And it's muddy under the van).
B
WAIT!! Trouble is, others say temp in hws is set at 50, and I measure at tap 50. See early posts this thread.
So now I have to get under the damn thing and screw about. I suppose that I look for a 2-in and one out somewhere not too far from the hws.
Easier than that. You probably have a pressure relief valve accessible from outside the van (in the HWS compartment at the top of the heater), just like on domestic systems. Flip the spring loaded valve and scalding water should squirt out.
If you operate that and the water is too hot for comfort you have your answer. In my case, it hurts when splashed on my hand but not so hurt as to burn painfully. You may be able to feel the hot pipe as it exits the heater. Of course maybe yours is storing at only 50 degrees, indicating a fault with your thermostat but that would be unlikely.
-- Edited by Are We Lost on Monday 30th of March 2026 01:17:52 PM
