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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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.
__________________
Procrastination, mankind's greatest labour saving device!
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 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.
