Hi Crew, Please can you give me a clue to help me troubleshoot or understand a possible issue. We have a hot water cylinder which my wife thinks has started smelling today, I can't smell it, and we still have hot water, but my nose is not that crash hot so not sure. One thing noticed is that the power switch mounted on the wall which connects to the cylinder is really hot, barely touchable. Is this normal or a clue to a problem?. Thanks Folks T
vivac,
Jan 11, 6:29pm
Sounds like the switch might be burning out, time to call an electrician unless you are competent to change it yourself.
tammythunder,
Jan 11, 6:54pm
thanks that makes sense. Might err on the side of the caution with this sort of issue.
tsjcf,
Jan 11, 6:56pm
One of the connections in the HW switch have become loose or the contact has failed. Turn the power off and have a look or call an electrician. Sometime can be from somebody changing a 2kw element for a 3Kw and not checking the switch rating.
tammythunder,
Jan 11, 7:15pm
thanks, that makes a lot of sense. I suspect tsjcf you are on the money. My wife is calling an electrician. We had someone put in a hot water cylinder a couple of years ago I am not sure about. So a professional could give us piece of mind.
androth2,
Jan 11, 7:43pm
Any electrical fitting which gets hot is faulty. As an example some people plug a 2 Kw heater into a wall socket. The plug on the heater is faulty/worn out so it heats up and ,transfers the heat to the wall socket via the metal contact blades.Eventually the wall socket plastic melts and catches fire from electrical arcing,and the fire travels up the cable inside the wall to the ceiling ,so you now have a major house fire due to an electrical problem
tammythunder,
Jan 11, 7:53pm
I love the DIY section always kindred souls and great advice. Thanks Androth too.
johotech,
Jan 11, 8:11pm
You're being very over dramatic, and lacking on facts.
The only accurate part of your post could be referring to something being faulty.
There's nothing wrong with plugging in a 2kW or 2.4kW heater. That is exactly what they are designed to do.
And power points actually catching on fire and burning inside a wall, is extremely rare. Electrical fires are much more likely from faulty appliances or power boards setting something else on fire, like curtains.
tweake,
Jan 11, 8:14pm
good to see someone taking the advice. i've had so many customers over the years where i've shown them or throw out, their melted plugs/double adapters/ multi boards, only to come back some months later and they are still using them. or they have fished them out of the bin and reused them.
johotech,
Jan 11, 8:14pm
Switch off the hot water at the switchboard. It should be marked as to which circuit breaker it is (or fuse if it's that old).
Don't risk leaving it turned on.
A switch like the hot water switch next to the cylinder can get warm, but it should never be so hot that you can't touch it.
tammythunder,
Jan 11, 8:58pm
THanks heaps and yes I did that. Electrician ordered.
androth2,
Jan 12, 10:12am
You should wake up to reality and not put rubbish things you dont know much about
vivac,
Jan 12, 10:57am
Johotech is a sparky, he likely knows more about this than you do. He also hands out pretty good advice on this board frequently, only once have i found his advice questionable. 2kW can be supplied through a socket outlet, those little fan heaters, a jug, a toaster, those are all usually 2kW-2.4kW.
androth2,
Jan 12, 12:04pm
He is not the only one with electrical registration,quite a few trademe people are also electricians but not a lot are fire investigators. You have not noticed that the my comments were about faulty plugs on load ,not normal use
johotech,
Jan 12, 12:54pm
Fire investigators aren't electricians. And electricians don't need to be fire investigators to know what causes fires and what doesn't.
We have to fix burnt out stuff that hasn't caused a fire all the time. Including electrical stuff that has actually burnt, but hasn't burnt down the building.
gary06,
Jan 12, 3:37pm
I come across this quite a few times these days where the hw switch is burnt out and it's almost always down to someone replacing a blown element with a much larger one ie replacing an old 1500 w element with a new 3kw one. The old pcu switches were 6 amp and it doesn't take long for them to melt. I've also found plumbers replacing leaking tanks with a new one which can come with 3 kW elements these days as standard. A lot of plumbers will reconnect cylinders when they aren't supposed to thinking they are doing the owner a favour. Get a sparky especially if you have had a plumber recently.
210sback,
Jan 12, 5:34pm
the fire travels up the cable.LEL.
vivac,
Jan 12, 6:10pm
Yes, seen my fair share of new 3kW cylinders reconnected to the old 1mm cable feeding the old 2kW cylinder.
vivac,
Jan 12, 6:12pm
Yes i did, also part of your original post is wrong. Fire investigation is interesting though, how did you get in to that?
andrew1954,
Jan 12, 6:31pm
The bottom line is no electrical fitting should not ever be “too hot to touch†get a sparky to look at it sooner rather than later. any sparky worth his / her salt will remedy the problem and ensure that the root cause is addressed. Electrical problems can not be fixed by guess work and / or correspondence!
johotech,
Jan 12, 6:51pm
Not that I want to continue this crazy discussion, but "too hot to touch" is not very hot. Around 45-55 degrees. A lot of fittings, especially cable, is designed to run hotter than that.
ianab,
Jan 12, 11:00pm
While this is true, if a switch or domestic cable is heating Itself up to that extent, then there is a problem. Loose connection or contacts burning out most likely. Most likely to fizz and smoke, then you lose hot water. But worst case it could catch fire.
Easy enough for any sparky to fix once they have a look at it and see exactly what's wrong.
vivac,
Jan 13, 10:33am
Does that include heaters?
210sback,
Jan 13, 8:59pm
you've got problems if a cable surface temp is 55 degrees due to operating conditions. While they may be designed to hit that temp due to external conditions eg atmospheric temps if its getting that hot due to current carrying its undersized.
johotech,
Jan 14, 12:06am
You might want to check some tables. 2.5T&E, partially surrounded, 16A = 56deg @ 20A, it's 71deg All well within design specs for the V75 cable.
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