Testing an immersion heater

[rocketmanbkk]

Friends

Electrics are my strong point but I'm no dimwit!!

I want to know exactly how to test whether an immersion heater or element has gone pop.

I've searched the www but haven't found what I need.

Any pointers to any sites/books with clear instructions & what the test readings will indicate would be greatly received.

Thanks

Rct

 

[Centralheatking]

To be honest if its not the fuse on the fixed switch then we always
replace the whole unit because there is no money in mucking about
with these units they are really cheap and dont take long to replace Its not really worth a second visit our customers know and are happy with this approach CHK

Friends

Electrics are my strong point but I'm no dimwit!!

I want to know exactly how to test whether an immersion heater or element has gone pop.

I've searched the www but haven't found what I need.

Any pointers to any sites/books with clear instructions & what the test readings will indicate would be greatly received.

Thanks

Rct

 

[townfanjon]

Easiest way is buy a multimeter with a clamp, turn it on , clamp the live wire and see if there's any voltage there. Don't just check for a live because it doesn't actually tell you if it's working. I never change a imm heater unless it's knackt , it's usually the stat.

 

[mfgs]

You can test the resistance, I think it should be 19 ohms off the top of my head.

 

[Masood]

Check 240V between incoming live to stat and neutral. If OK, move on. If not, check fused spur.

Turn stat all the way down and test for voltage between live out from stat and neutral. Should be 0. Turn stat up and test again. Should have 240V. If not, stat knackered.

If stat OK, check resistance of heating coil. As already said should be ~19 Ohms.

 

[Centralheatking]

19 ohms of the top of your head ? sorry CHK

You can test the resistance, I think it should be 19 ohms off the top of my head.

 

[kris]

Best and most accurate ways is to test the resistance and also if competent use a megger, the megger is great and will tell you if the element is broken, blast 500v through it lol

 

[kris]

Does the Resistance reading not vary depending on the size of the element ie, 27" 8"

 

[kris]

Best and most accurate ways is to test the resistance and also if competent use a megger, the megger is great and will tell you if the element is broken, blast 500v through it lol

Ment to say you can also do a simple continuity test with a standartd meter to test the element ,,although not as accurate as megger

 

[kris]

Jumping the gun, obviously make sure youve 240v at the stat,

 

[Masood]

Does the Resistance reading not vary depending on the size of the element ie, 27" 8"

Not as far as I know. They are all 3 KW but longer ones have more surface area so dissipate heat better.

 

[kris]

Yeh theyre all 19.2 ohms, cheers masood

 

[buckley plumb]

Yeh theyre all 19.2 ohms, cheers masood

I am ok with electrics but never used a mega tester have you any good links mate

 

[townfanjon]

I am ok with electrics but never used a mega tester have you any good links mate

Lol , you want want a link when you see the prices, LOL there mega !!!

 

[newcastle phill]

I have a megger.
My preffered way to test elements. No ambiguity with resistance values. It will indicate continuity through the element or open circuit.
Also good to test from element to earth in case the insulation is failing and leading to spurious trips

 

[buckley plumb]

Lol , you want want a link when you see the prices, LOL there mega !!!

got one mate had it from when I used to fix forklifts but never used it its still in box

 

[Best]

Firstly check the stat has power through it. If it hasn't, then check on modern heaters the manually resettable cut out. (If someone puts clothes over the immersion cover the cut out goes off, or if cylinder is overheated. Hence why it says "do not cover")
Next check live & neutral going to the heater. Neutral part of spur can be burned out or a wire out.

 

[newcastle phill]

Old faithful

Will pump out 250 500 or 1000v and make faults apparent that other means won't show up.

 

[helpsy]

Ohm's law triangle. I
-------
E | R

Another handy one

W
------------
V | A

 

[helpsy]

I
-----------
e | r

 

[solutions]

Ohm's law triangle. I
-------
E | R

Another handy one

W
------------
V | A

Yay love 3 ways.
Theres an app for that.