immersion testing.

[arakassi1a]

hi all. just found your forum. newly qualified spark here.

can anybody help me to understand how to check if an immersion heater is good or not and which tests to use. and also the same for storage heaters.

all help much appreciated and accepted humbly.

cheers!

 

[Evans Electric]

Immersion heater :- obviously check for mains, then check the stat is calling for heat, then if a modern one, check the overheat device, then if there is 240v across the element it should work. If it does not , do a continuity test on the element (looking for approx 16ohms) and also megger it to earth (at 500v) . Any earth leakage, replace it or get a plumber to do it if you can't get it out , old cylinders can be a nightmare. The last few I have gone to , the cylinder had to be replaced as trying to unscrew the heater beggered the tank up.

Good luck with it,

Deke

 

[Evans Electric]

Storage heater not working, could be the input stat turned down too low or its faulty. The over- heat fuse may have blown, usually mounted in the top, melts if clothing or anything is piled on top of heater, get spare from makers ,do ot short it out. Elements could be gone, check for mains voltage at each one, then continuity of element. Elements are readily available. You may need to a temporary supply for testing. And you need to know that the restrcted supply is switching on at midnight. Change the switch to one with indicator and ask the customer to look for the light.

Really old heaters contain ASBESTOS so you don't dismantle them !!

Deke

 

[SPECIAL LOCATION]

Immersion heater :- obviously check for mains, then check the stat is calling for heat, then if a modern one, check the overheat device, then if there is 240v across the element it should work. If it does not , do a continuity test on the element (looking for approx 16ohms) and also megger it to earth (at 500v) . Any earth leakage, replace it or get a plumber to do it if you can't get it out , old cylinders can be a nightmare. The last few I have gone to , the cylinder had to be replaced as trying to unscrew the heater beggered the tank up.Good luck with it,

Deke[/quote

bit nearer 19ohm to 20ohm

typical domestic Immersion heater is rated as 3000watts @ 240v and

2700watts @ 230v

(240x240)/3000=19.2ohm

(230x230)/2700=19.6ohm

 

[arakassi1a]

hi, thanks for your replys. that has cleared things up for me, wasn't sure on the meggering the element part but no problems now. it is great to get info as it gives the confidence to a newbie to go at things.

again thankyou

 

[SPECIAL LOCATION]

hi, thanks for your replys. that has cleared things up for me, wasn't sure on the meggering the element part but no problems now. it is great to get info as it gives the confidence to a newbie to go at things.again thankyou

Go for it!

these very little you can knacker up on an immersion heater even with a megger, 3kw element it quote a robust thing!

 

[Evans Electric]

Immersion heater :- obviously check for mains, then check the stat is calling for heat, then if a modern one, check the overheat device, then if there is 240v across the element it should work. If it does not , do a continuity test on the element (looking for approx 16ohms) and also megger it to earth (at 500v) . Any earth leakage, replace it or get a plumber to do it if you can't get it out , old cylinders can be a nightmare. The last few I have gone to , the cylinder had to be replaced as trying to unscrew the heater beggered the tank up.Good luck with it,

Deke[/quote

bit nearer 19ohm to 20ohm

typical domestic Immersion heater is rated as 3000watts @ 240v and

2700watts @ 230v

(240x240)/3000=19.2ohm

(230x230)/2700=19.6ohm

I measured the last one I fitted Specs, 16ohms , what can I say ! :|

Deke

 

[tricky01]

hi all. just found your forum. newly qualified spark here.can anybody help me to understand how to check if an immersion heater is good or not and which tests to use. and also the same for storage heaters.

all help much appreciated and accepted humbly.

cheers!

Simple test , Step 1 Ensure thermal cutout has not popped out . If so push back in and turn immersion back on.

Step 2, If thermal cutout Ok then do simple continuety test as follows, On probe set thermostat to lowest temperature and with tester across both points should have open reading. Then turn up stat till click herd and should also get reading. Proves stat good. If still open circuit them change stat.

3. If all above good then proceed to test immersion . Simple continuity test again .One probe on neutral of immersion other on high side of stat should show closed circuit.Now turn stat to lowest point if still closed then suspect blown immersion and change

 

[SPECIAL LOCATION]

I measured the last one I fitted Specs, 16ohms , what can I say ! :|

Deke

dunno m8 but...

16ohms @230v is 3.3Kw or 14.3A

16ohms @240v is 3.6kw or 15A

seems a tad high to me. AFAIK they are normally no more than 13A? :|

(I got one sitting here it measures 19.4ohm)

But I ain't going to loose sleep over it.. :x

In a nutshell you should be reading between 16ohm - 20ohm.

if not its most probably knackerd!

 

[springcrocus]

As the temperature rises, so does the resistance. Maybe 16 ohms is the cold reading, rising to 20 ohms under full load. ?:|

 

[SPECIAL LOCATION]

As the temperature rises, so does the resistance. Maybe 16 ohms is the cold reading, rising to 20 ohms under full load. ?:|

19.5ohm...

cold

still in the box! :|

the plot thickens!