Immersion heater and clamp meter question

[jackfrosty]

Hi, got asked to have a quick look at an immersion heater which has packed up. Just trying to decide which is broken, the timer or element

The actual immersion heater element all seemed to test out ok: >500 L-E 19ohms between L-N and 19.4 on the other element. Also when time clock is rotated manually i got a reading of 240v on and off on the immersion.

I dont yet have a clamp meter so cant check the current being pulled but how would this be done? A clamp meter on the incoming L tail with everything else turned off? also would the

 

[Apache]

I dont yet have a clamp meter so cant check the current being pulled but how would this be done? A clamp meter on the incoming L tail with everything else turned off? also would the

 

[m4tty]

+1 on the Maplin jobbie.

 

[sparkytim]

Did you check continuity thru the Thermostat(s)?

 

[jackfrosty]

yeah i did, and thats the reading i got

 

[sparkytim]

So when you got 240 Volts at the Immersion could you HEAR it heating?

(Stick your ear on the cylinder if its not obvious)

 

[jackfrosty]

that the thing, its got that foam coating around it so made it hard to hear but couldnt hear it heating, also left on for an hour i recon and didnt heat up, just confused because it tested out ok

 

[m4tty]

Has it got a thermal cutout? Which may of tripped. I may be talking carp tho lol

 

[Apache]

that the thing, its got that foam coating around it so made it hard to hear but couldnt hear it heating, also left on for an hour i recon and didnt heat up, just confused because it tested out ok

1. Is there power to the element?

2. Does the water get hot?

If the answer to 1 is yes and 2 is no, then try swapping the thermostat. Repeat 2 again. If not heating up still swap the whole thing.

 

[jackfrosty]

Thanks il give all above posts a go

Cheers

 

[PC Electrics]

In the absense of a clamp meter, you could watch the meter. At the point of switch on the wheel or flashing red light should speed up considerably if the full 3kW is being pulled.

Are you sure you've tested continuity across the stat? and between the stat and connections?

 

[jackfrosty]

what is this matty mentioned about the thermal cutout? what causes this to trip exactly?

 

[sellers]

what is this matty mentioned about the thermal cutout? what causes this to trip exactly?

Overheating, shorts, leaks?

This is how I test. Switch on power to the element, test for 240v at both sides of thermostat, if ok, test at both sides of cut out, if ok test at element, then, switch off and check continuity of element.

If your cutouts tripped you can reset it by pushing the button inwards. If your havent go voltage at both sides of the termostat when cold then that is fauty.

found this pic to help

 

[Apache]

what is this matty mentioned about the thermal cutout? what causes this to trip exactly?

mmm, lets see. Maybe it cuts out on leap years, or Sandra's birthday?

My thinking is in the case of overheating?! Ie if set too high or thermostat knackered. Just the rambling thoughts of the veterinary....

 

[jackfrosty]

thanks, if it turns out to be the element what are the tips and tricks to remove it? Ive been warned about the cylinder twisting

 

[sellers]

thanks, if it turns out to be the element what are the tips and tricks to remove it? Ive been warned about the cylinder twisting

Get a plumber!! Best bet mate, to much hasel if it goes belly up. Just look at Noz's thread! I just diagose, and ring my plumber up. Then if there are any further problems with the system, he'll be able to tell.

 

[Apache]

The other thing that has been mentioned before is that your liability insurance as an electrician may not cover you if you flood their house!

 

[jackfrosty]

didn't even think of not being insured! thanks for advice

---------- AUTO MERGE Post added at 21:11 ---------- Previous post was at 21:01 ----------

one last thing, someone told me that once the thermal cut out has cut out it is recommend to change it, do you agree?

 

[Manator]

didn't even think of not being insured! thanks for advice---------- AUTO MERGE Post added at 21:11 ---------- Previous post was at 21:01 ----------

one last thing, someone told me that once the thermal cut out has cut out it is recommend to change it, do you agree?

No! A thermal cutout is a safety device to prevent overheating of the system, if it does not reset by depressing the reset button then change it.

 

[Andy™]

one last thing, someone told me that once the thermal cut out has cut out it is recommend to change it, do you agree?

if the thermal cutout keeps tripping, it may well be because the thermostat isnt working and its getting too hot. so thermostat may need changed.

also be aware that older immersions may not have a thermal cutout and oly have a thermostat