The element has been replaced. The thermostat has been replaced twice. The reset switch is still tripping. An electrician has checked the wiring back to the switchboard and said that it was fine. What do I do now!
aredwood,
Jan 19, 11:51pm
You obviously don't know what you are talking about. Have a look at the very first page of this pdf http://www.hjcooper.co.nz/brochures/downloads/hjcooper_premium_mains.pdf in the cutaway photo you can see the lower element is curved down. This is done so the water at the very bottom of the cylinder still gets heated. If the element gets installed so the curve is pointing up it will provide more heat to the water that is above the thermostat which can cause the cylinder to boil. And cause the problem that the OP is having. There isn't any key or notch that stops those elements being installed the wrong way around.
trade4us2,
Jan 20, 1:28am
Presumably the thermostat temperature can be adjusted. What temperature is it set at! What is the maximum temperature of the water out of the tap! Is the water steaming! How long can you hold your hand under the tap! I still reckon the thermostat is the problem, and a competent sparky with a multimeter and a megger could check it in a pot of hot water.
captaingraham,
Jan 20, 2:22am
Is it possible you have mice or rats chewing on the supply cable. This could trip the breaker and test ok once ratty had either died or moved on to a feed that does not shock him. A visual inspection of the cable is needed along the whole length of the circuit!
jaffa77,
Jan 22, 9:09am
I have been trying to think through my problem logically as I am stumped and not sure what to do next.
Starting from the meter box.the hot water is on ripple relay. The fact that I have hot water sometimes suggests that the relay is working fine. The power company have said that if there was a problem with the relay then it would trip the circuit breaker on the switchboard rather than the tripping the reset button on the thermostat. They will send someone out to check it but it will cost me $148 + GST if there is no fault found.
Next along from the meter box is the wiring from there to the cylinder. One electrician has checked it using some sort of meter and said it is fine. I am inclined to agree with his assessment as I would think I would have different symptoms if it was faulty - eg maybe the meter board circuit breaker would trip.
Next is the element - this must be working Ok as I have hot water at times. It was also replaced last week and the problem still persists.
So then we come to the thermostat. I understand that this should have 2 parts to it - one to detect when the water is at the required tempearature and turn the element off, and the second is some sort of safety override that trips if the water gets too hot. If my understanding is correct, then it seems that the first part is not working. Why would this be! I am now on to my 3rd thermostat. I can understand that the first may have developed a fault that caused this to fail but this should have been fixed when the 2nd and then the 3rd thermostats were installed. Tonight the water out of the hot tap was steaming and way way too hot to put your hand under. Just as an experiment I tried dialling down the dial on the thermostat and heard it click at about 57 degrees. I am not sure if you should be able to put your hand under a tap if the water is 57 degrees.
If my thinking is correct can anyone suggest what the problem might be that means multiple thermostats do not cut off when the water reaches the right temperature or fail to detect the temperature accurately. Could it be a wiring problem that is external to the cylinder!
jaffa77,
Jan 22, 9:45am
One more thought - are there any other parts that live between the thermostat and the element that could fail! I am assuming that when the thermostat detects that the water is at the right temperature it sends a signal to switch the element off. Is this switch part of the element and thus would have been replaced when the element was replaced. I am just wondering if it is possible that the thermostat could be correctly detecting that the water is at the right temperature but the signal it sends to turn off the element is getting ignored for some reason.
trade4us2,
Jan 22, 10:22am
What temperature was it set to before you "dialled down the dial"! It should be set to 60 degrees. The thermostat needs to be tested by someone competent. It needs to be put in a pot on the stove with a thermometer and the water heated and it should switch off at the temperature on its dial.
lythande1,
Jan 22, 6:28pm
Yes husband, the plumber, told me about those, wrong way round and upside down, slight difference. Also she said originally she had the cylinder (and element) for ages, if that had been the case it wouldn't start after 3 years.
lythande1,
Jan 22, 6:30pm
You've had an electrician already haven't you! They would be able to test, they should have tested. Wiring and thermostats/elements. Or did you only have one electrician!
jaffa77,
Jan 22, 6:52pm
I have had 2 electricians. Thermostat was set at about 63 degrees yesterday when water from tap was too hot to put hand under and it clicked off at about 57 degrees when dialling down. The 2 replacement thermostats and one replacement element were installed by a plumber.
davea74,
Jan 22, 8:23pm
Not taking the proverbial, but did the plumber wire the new ones in!Not sure of the arrangement but is it possible that the overtemp. and control are swapped around!
Maybe you had a faulty thermostat the first time, when it was replaced the wiring was mixed up and subsequent ones have just been put back and wired the same way as they were taken out.
jaffa77,
Dec 26, 11:08pm
The reset switch on my hot water cylinder has tripped 4 times in the last 10 days with the result that I wake up to find that there is no hot water. I have had 2 electricians and one plumber to look at it. The thermostat has been replaced even though they couldn't find a fault with it. It has tripped twice since the new thermostat was installed. The electrician has checked the wiring back to the switchboard and couldn't find any fault. The element is also fine. I am thinking of replacing the hot water cylinder but without knowing exactly what the fault is, there is always the chance that the problem will recur with a new cylinder. The electrician suggested replacing the thermostat with one that doesn't have a reset switch but I don't think this is a good idea as I am not sure how the insurance company would view it in the unlikely event that I had a house fire. I would think they could legitimately decline a claim because I had knowingly removed a safety mechanism.
The cylinder is a mains pressure one made by H J Cooper. It was manufactured in 2006 but was only installed in 2009. The hot water is on ripple-relay. The fuse in the meter box has not tripped.
I have already incurred significant costs from the 2 electrician's visits and one from the plumber and from replacing the element. I haven't got the bills yet but I expect they will total well over $500.
What do I do now!
trade4us2,
Dec 26, 11:34pm
The electrician should check the current rating for the thermostat and that it is adequate for the element. It seems like the thermostat has welded itself closed and the water is boiling. If the thermostat is not the right rating they should replace it for nothing. If you can look at them safely (turn the heater power off first) the element and thermostat should have the wattage or current rating on them, e.g.3000 watts or 14 amps. etc.
velenski,
Dec 26, 11:37pm
reset switch! ,are you talking about circuit breaker on the switchboard!
jaffa77,
Dec 26, 11:48pm
The reset switch I am referring to is under the electrical cover on the tank itself and you need to use a paper clip or similar to press it in. The circuit breaker on the switchboard is not tripping.
trade4us2,
Dec 27, 12:13am
How frustrating. I have an old style copper 180 litre cylinder that cost $500 complete 20 years ago. A few years ago it started boiling so I bought a new thermostat for $30 and that fixed the problem. I tested the old thermostat in boiling water and it seemed to turn off and on OK. But it must have an intermittent fault.
I don't have a reset button.Maybe get a thermostat without a reset. If it boils you should hear that,and it should overflow safely. I'm not up with the latest designs, however they seem like crap to me.
aredwood,
Dec 27, 6:37am
The element is installed upside down. Those cylinders have their elements curved in a 1/4 circle shape. this is to make them hang down lower and therefore heat more of the water in the cylinder. If they are the other way up they will cause the cylinder to boil due to the top of the element being higher than the thermostat. You just need to drain the cylinder, take the element out and turn it up the correct way.
The above assumes that the cylinder is heated by electric element only. If you have solar panels or a wetback connected to it then they will be tripping the thermostat. Those thermostats trip when the temp gets to 84 deg.
wunderbar2,
Dec 27, 7:48am
aredwood is correct - If you do have a solar system on there ! you need to restrict the temperature to say 72-75 max- otherwise the Cylinder gets too ho and turns itself off .The other thing you can do is change the Thermostat to one that resets it self ( even so they sell you solar ready HWC _ they dont out the rigth Thermostats in those Cylinders ) they come as an " EXTRA" which is blimming annoying considering they only cost aboutUS$ 0.60 centsextra . But try redwoods trick first - thats probably where your problem is.
ashley5,
Dec 27, 7:59am
Have you replaced the element or not. If not it could be the element at fault as it heats up the element will expand and expose any cracks and cause the electrical fault and then when it cools down the element will test fine. I have found this to be the case on 2 different occasions
jaffa77,
Dec 27, 9:51am
My water is heated solely by electricity - I do not have any solar panels. I don't understand about the element being installed upside down. As far as I know, it is in the same position as when the cylinder was made. Did the manufacturer put it in upside down and I now need to rectify their mistake! Even if the answer is yes, it is odd that it worked fine for 3 years and then suddenly started playing up 10 days ago. I haven't replaced the element as it appeared fine when tested by the electrician. If it is as ashley suggested, then my understanding is that there is no way to confirm that the element is fautly other than by deduction by replacing the element and not having the problem recur. Unfortunately getting access to the element on these cylinders requires a key which I don't have so even if the electrician could get a replacement element he wouldn't be able to install it until we could locate this key. Goodness knows why anyone would come up with such a daft design.
lythande1,
Dec 27, 5:38pm
You cannot install an element upside down, it can only be put in the way it goes. It's like saying you put a lightbulb in upside down.
lythande1,
Dec 27, 8:59pm
You've replaced everything else. Ring a plumber not an electrician and get another element.
wunderbar2,
Dec 27, 9:17pm
Its not a daft design . (;-)Its a great way to make money !thats all Becauseevery time you need somethingyou need to go back to the "maker" of the HWCand you can not buy it from somewhere else . If your HWC has been working fine for all that time - its either theElement that is buggerdor the Thermostat . Soreplace both of them and call it a day . ( you wont be able to claim on the warrantyas Elements and Thermostats haveusually only 12month on them ( the HWC itself is a lot longer )The keys- you can buy them FROMHJ Copper -but I thinkthey just started to include them recently( because there where not too many happy campers out there ).
killy1,
Dec 27, 9:51pm
Seems to me that the element is fine. The problem is one of the parts of the two stage thermostat. Cooper thermostats are a special and give more trouble than most.At this point I would replace it with an EGORC30 . This will overcome the problem with the Eurotech thermostat.
lythande1,
Dec 28, 12:28am
Seems to you! Are you a plumber! vague possibility the relay is at fault but I doubt it, the electrician would have found that. Change the element.
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