I'm an electrical inspector. The element heats the water when its turned on, therefore the element is ok. The thermostat is 2 stage, 1st stage cycles the hot water for normal use at say 60degrees, the 2nd stage is a safety cutout which will turn off the water at, say 70. The thermostat is faulting occasionally and then it needs manual reset. So either stage 1 is not turning off and then stage 2 overrides. Or stage 2 has set itself too low and turns off the manual override. The relay cannot be blamed as the op wouldnt be able to reset it.
jaffa77,
Dec 28, 11:37pm
Hmmm.the problem has persisted even after replacing the thermostat. Water will be fine for a couple of days then the reset trips. I can understand the original thermostat developing some fault that may cause this behaviour but its weird that it still happens even after installing a brand new thermostat. I have already incurred 3 call-out fees and there will be a fourth. I am not a happy camper as the cylinder has been installed for less than 4 years and so I should have been able to reasonably expect to go for ages without having problems. The callout fees and lost income from taking time off work to wait for the tradies will probably cost more than it would have cost just to install a new cylinder, which I will probably end up doing anyway as I need reliable hot water. I wouldn't mind so much if we could conclusively determine what the fault was so it could be fixed, but without this conclusive diagnosis, it seems like replacing the thermostat and/or element are being done on a suck it and see basis.
trade4us2,
Dec 28, 11:50pm
It should be possible for the thermostat to be tested. i.e.put it in hot water on a hotplate and measure when the resistance goes high. But maybe sparkies don't do such things these days.
lythande1,
Dec 29, 12:57am
Ashley5 had the right idea, an element can fail without a total failure. Also, jaffa77, if they have not fixed your problem, you can call them back- without further charge - to actually fix it for you. They cannot legally just keep charging you money and not fixing the original issue. Keep your invoices and if they won't co-operate take it to Disputes. A lot of plumbers are clueless about power and a lot of electricians are clueless about plumbing. Seriously you persist in going on about the thermostat, but no0one has changed the element yet.
easygoer,
Dec 29, 1:56am
Get a new Sparky, I'll back Ashley5 on this one, I would guess that if the element is removed you will find a split or blow out on the neutral side of the element.
easygoer,
Dec 29, 1:59am
Did the Electrician check the element with a megger and ohm meter then use his clip-on ammeter to check current draw!,one or all of the tools should have given him the answer.
spirogryo,
Dec 29, 2:15am
Always use the OLDEST tradesman you can find.
elect70,
Dec 29, 4:26am
Is the resetfor overtemp or electrical fault!havent stuck 1 those yet
russ18,
Dec 29, 4:57am
An electrician will be able to diagnose a failing element, don't know any plumbers that can.
taipan4,
Dec 29, 5:49am
ffs replace element and thermostat and be done with it and then you can eliminate the two most obviouscomponents likely to fault. in the old days thermostats used to be simplebut THEY who know best come up with these super duper ones LOL
captaingraham,
Dec 29, 5:51am
Correct. Simple tests that any competent electrician could do in a few minutes.
ryanm2,
Dec 29, 9:05am
thats the worst advice ever.
lythande1,
Dec 29, 7:00pm
I do.
taipan4,
Dec 29, 7:55pm
#27 prepares--to do battle with 4000 greyhaired balding ageing sparkies all 60++++we might be old but most of us have aeons of experience LOL
ryanm2,
Dec 29, 8:23pm
some of the older sparkies ive came across (not where i work though) dont even know what an LED is. Sure, with constants like HWC where nothing really has changed in the last 60 odd years experience is great, often you can pin point the fault just by the customer description. I watched an old fart using a tone tester the other day, painful.
taipan4,
Dec 29, 10:14pm
yes depending on the amount of nouse shown by the customer BUT when you're on the phone & you get something like "the thingy on the switchboard is doing something & the whatsit on the cylinder is clicking (sometimes) do you think it could be the square shapedfusey thing with a round top next to where the smoke is coming out LOL
jaffa77,
Dec 29, 10:56pm
The element has been tested by 2 different electricians using some type of meter and both thought it was fine in that it was drawing the correct amps. Is it possible that it could have a partial failure (eg split or blow out on the neutral side of the element) and still draw the correct amps!
elect70,
Dec 30, 1:48am
^^ Yes ive come accross fewsometimes day later, taken element out & its split through, they always give a low test reading& can stilldraw full amps .Get an "incalloy " 1last longer esp ifhard water .
killy1,
Dec 30, 1:51am
A faulty element will NOT trip an overtemp. All of us are making assumptions due to experience, I started my apprenticeship in 1960. As the op says in #4 the thermostat has to be reset, the element cannot cause this problem. I stand by my comments in #16.
lythande1,
Dec 30, 4:30am
Yes. Come on, common sense. You've had it tested.you've also had the thermostats replaced and that's done nothing. Process of elimination if nothing else.
trade4us2,
Dec 30, 4:30am
The problem is a faulty or unsuitable thermostat.
taipan4,
Dec 30, 5:13am
yup there aint a lot of separate parts to a hot water system,
russ18,
Dec 30, 7:18pm
Well you would be the only one I've ever heard of to have an insulation resistance tester. I have replaced elements after plumber has already been and tested with his cheap multimeter and incorrectly concluded that the element's ok. Still better off with a sparky because they can all diagnose this fault.
t_naki,
Dec 30, 7:32pm
I agree, I have been to a faulty HWC that 2 sparkies from the last company I worked for had both been to and said it was fine. The first thing I did was put the megger on it and it was faulty. If you have replaced the thermostat and it is still tripping then there is not much chance that it will be anything else but the element.
jaffa77,
Jan 22, 7:17am
Apparently the thermostat is all pre-wired so you couldn't get the cross over you suggested even though it sounded like a feasible explanation for the problem.
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