Hot water temperature

Gwian · Senior Member

Hot water temperature

Peter_n_Margaret · Guru

Does it have a tempering valve fitted?

Cheers,
Peter

Gwian · Senior Member

Hi Peter

Just had a look thru the specs for the heater and nowhere does it say anything about a tempering value. It only talks about safety pressure value and a pressure reducer valve.

Gwian

Baz421 · Guru

Could be a common problem it seems>

This extract is from another forum-

Have you checked the even more blindingly obvious like the thermostat position on the rotary switch.

Does the green light on the switch come on. If not is there power into the fused spur. Then follow the power round to the heater and where the power stops is the problem.

It can only be a few things if the heater isn't bust.

1. Breaker off on power board
2. Fused spur Switched off, fuse gone
3, rotary switch faulty, stat turned down.
4. Bust heater/loose connection.

Also go to exploreoz.com for info on these heaters in their forum.

I think Dometic is the agent - maybe give them a call 03 9239 1000.

Hope this helps.

Peter_n_Margaret · Guru

The tempering valve is not part of the heater and therefore will not be in the heater specs.
It's purpose is to stop scalding water being delivered to the bathroom.
They are adjustable for outlet temperature and mix cold water with the hot.

Cheers,
Peter

Baz421 · Guru

Gwian For info the tempering valve referred to earlier is called a thermostatic mixing valve (TMV) in Oz when specifying this valve in plumbing systems.

Big Dave · Member

Just to set the record straight a thermostatic mixing valve is only used in high risk areas eg. health care/aged care. A tempering valve is used in all other stuations such as in a caravan, possibly yours. They are usually installed under the van, just trace your hot water line from the heater outlet to find it - if you have one.

I think the hot water problem is more of a thermostat on your hot water heater.

rockylizard · Guru

Gday...

This is what a Tempering Valve looks like -

Temper 01.gif temper 02.jpg

Cheers - John

Baz421 · Guru

OK I'm not a plumber Big Dave and you are right TMV's are used extensively in those applications you mention.

I therefore have a question? The diagram in rockylizards post shows the thermostat component does it not? This valve doesn't rely on pressure but temperature and manual adjustment for flow?

Would it not be better to have a TMV (they are cheap these days) that uses a thermostatic control rather than springs for flow control in a caravan, especially as you use mains pressure one day and 12V pump the next?

Hopefully someone has the answers as I'm curious and I know that the caravan industry will probably go for the cheapest option.

KFT · Guru

G'day everyone,

The fact that the water temp is HOT when first turned on indicates that the Heater is most likely getting up to temperature you can check this at the pressure relief valve on the outside of the heater by releasing some water by pulling up on the pressure release test lever. If the water coming out of the heater is HOT then it is not the water heater. If the water then cools down I would strongly suspect the tempering valve has cut in to cool the outgoing hot water to a safer temp, usually around 55-60 deg c. If the water coming out of your hot wate tap is cooler than that I would look to repair or replace the tempering valve.

avagreatchrissy

frank

-- Edited by KFT on Friday 21st of December 2012 09:06:02 PM

Gwian · Senior Member

Thanks to all those advisers who have given me plenty of options. KFT, John and Peter appear to be on the right track and when I have solved the problem I will let you all know.

Thanks again

goldcoaster · Senior Member

Hi Gwian,
Is this problem at all your outlets eg. Sink, Basin, Shower. If it is only at your Sink and you have a Flickmixer tap, it could mean you have one of the new Safety Flickmixers. To avoid scalding you have to turn and hold Mixer handle further to the left to get Hotter water,when released it will go back to Safety 50 deg. TMV's would not be good for Caravan and Motorhome Installations,they are big and cumbersome and must be tested by a Licd. Plumber who has done the required course,records must be kept by the Plumber and the Owner of the TMV.Tempering Valves are the way to go if you want your Hot water at 50 degs. at whatever outlet you install it on.I wouldn't waste your money and time to install one,unless you let the Grandkids play with your Hot Water. OHS is out of control,as a Baby Boomer I dont know how we survived all these years :)

goldcoaster · Senior Member

Forgot to add,Tempering Valves should only be adjusted when Hot Water is not at 50 degs, at all or the only outlet you have it installed on. Should only be carried out by a Licd. plumber and then your covered.