There was a bang, a rather large spark, and the fuse tripped. There appears to be burning around the thermostat connection, and the spark was enough to burn a small hole on the metal cover.
I assume that in removing the cover it touched something that caused this? Thankfully I was wearing rubber coated gloves at the time, so who knows if I would have got a shock. But the question is, is it safe to flip the fuse back on and return power to the tank?
Unfortunately this is in a rental we have been in less than two days. The shower water was scalding, so I decided to check the thermostat setting, hence the reason for being any where near it. Turns out it is jacked up to maximum, which appears to be over 70, if that is possible.
I have adjusted thermostats before, but have never has such a thing occur on removing a cover.
intrade,
Dec 26, 4:51am
you dont give glear enough information. be carfull power can kill you or weld your heart artehrials shut its not to be messed with unless you know what you are doing and you clearly dont seem to .
intrade,
Dec 26, 4:56am
if there is a short power can flow in to the water and if not all taps are grounded you will get zapped by the water taps water and electricity = high chance of death. Do NOT RE-SET the fuse! unlesss you have a death wish.
intrade,
Dec 26, 5:01am
electrition must check if the thermostat is faulty replace it adjust it and mesure the taps and plumbing is correctly earthed , a earth wire must be attached to every metal sink and plumbing pipe . if the electrition does not do this then you you had a moron vist whom should not have his license.
zoopa,
Dec 26, 5:08am
All I did was pull off the cover to adjust the thermostat. There was a bang and a flash. The fuse tripped. That is all. I am not 'messing' around with anything, because I am not stupid. That is why the power has not been returned to the cylinder
zoopa,
Dec 26, 5:11am
Thank you. I will call the landlord in the morning and he can deal with it.
Any idea why it would short out simply by removing the cover? I assume something touched something it shouldn??
pamow69,
Dec 26, 5:23am
You answered your own question. Why did it short out? There is a small burn hole in the metal cover & a burn mark on the thermostat connection. Obviously as you moved the metal cover it touched the live wire connection on the thermostat. First thing you should of done was switch the power off before removing any covers. There should be a switch next to the cylinder. If not then pull the fuse on the board.
zoopa,
Dec 26, 5:39am
I figured the metal cover had shorted it, but am surprised it happened so easily. Guess it was luck it hadn't happened before on other occasions? Can't believe I didn't even think about killing the power! I am so aware of that with machinery etc. Duh
Is it usual to just have a bare metal cover over the unit? I can't remember the others I have looked at.
daryl14,
Dec 26, 1:21pm
Seems strange that it shorted so easily. Is the terminal very close to the front? Or maybe there is something loose or debris in there? Most designs should have the terminals fairly well shielded from prying fingers etc. Maybe you poked the screwdriver in there without realizing? Can you upload a pic? If you can get it back on without touching the terminal with the cover then it might be okay to turn the power back on to it.
gamefisher,
Dec 26, 1:29pm
Sound to me that the incorrect power source has been isolated posibly due to incorrect labeling a sparky would normaly always test if there is power before they touching anything.
daryl14,
Dec 26, 1:34pm
He didn't isolate power first, just pulled off the cover. Which is probably what I would've done. You should be able to do this to adjust the thermostat without fear of getting a shock in most installations, I would have thought. Pretty sure there are regulations on having the thermostat up so high that it could burn someone nowadays too, especially in a rental.
gamefisher,
Dec 26, 1:58pm
If the thermostat in under the cover it is an normaly an electricians job or a compitent person ( they would isolate) if the thermostat outside any adult can adjust.
car27,
Dec 26, 2:01pm
You always turn the power off first before removing the cover
russ18,
Dec 26, 3:05pm
What side of the thermostat shorted, the live or switched side? If the swiched side then the thermostat has had a short circuit fault current across its contacts and I wouldn't trust it any more. Sounds like some sloppy workmanship or deteriorated wiring for a short to occur just by removing the cover. IMO Should get a sparky in to check it out.
aredwood,
Dec 26, 11:24pm
There are alot of cylinders out there with thin foam insulation. (complies with insulation rules at the time) Which have the terminals close to the surface. As a result these cylinders have a bulge in the cover to keep plenty of clearance between the terminals and the cover. But if you are not careful with removing that type of cover then you will cause a short or electrocute yourself.
And yes a bare metal cover is normal. As the outside case of the cylinder will be earthed. So the cover will be as well. And since it is held on with screws. It is intended that only qualified people are going to be opening it. and that the power will be disconnected before opening. As a qualified person will know how to check that the power is disconnected before opening.
You should have phoned the landlord and asked them to turn the temp down. As if they have to send out an electrician, They will be allowed to bill you for the full cost of repairs.
zoopa,
Dec 27, 1:24am
The cover pretty much dropped off as soon as I touched it. No tools involved. It is hanging underneath. With no cover on, everything is exposed.
I know now why I didn??
zoopa,
Dec 27, 1:25am
No screws, it fell off when I touched it. That's all I touched. It is also has a large storage area underneath it, so I suspect it could have been knocked off by putting things in there. Not the best arrangement.
zoopa,
Dec 27, 1:37am
Will get pic when back at house tomorrow. No terminal shielding with cover off,
marte,
Dec 27, 7:42am
I think the cover mentioned is the zinc coated sheet metal circle. If it touched one of the element connections, it would have shorted against the zinc covered sheet metal surround holding the insulation onto the hot water cylinder.
Shouldn't have gone poking in there without disconnecting the main fuse link.
elect70,
Dec 28, 10:09pm
Bet the wire was loose in the connection in t stat & when pulled the cover it came out & touched metal case . get new t stat from plumbing shop or electrical wholesaler . . & reterminate , it aint rocket science
fungles,
Dec 29, 3:16am
Just wind the temp down, reassemble the cover and reset the circuit beaker. All metal covers are bonded to ground . you have shorted the case to the phase. hot. side of the mains is all. There is no damage other than a very good lesson to switch off any appliance before fiddling. Dont worry, we have all done this at one time in our lives. Its called interactive living.
johotech,
Jun 24, 9:43pm
So you posted this to prove that you are NOT an electrician and know basically nothing about electrical regulations and standards?
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