Testing the heating element in a water heater
 

I have a Solar panel connected to the Immersion heater and recently the
water temperature has dropped dramatically even with the Immersion
heater on. I have removed the element from the heater but would like
to test whether the element is working. is there a simple way of doing
it? The pipe at the top of the tank seems quite warm but not sure if
thats the panel heating it up or the immersion heater. Thanks

Testing the heating element in a water heater
 

Testing the heating element in a water heater
 

Actually wouldnt a reading of 0 ohms indicate a short? I thought the
way a heating element worked was due to resistance to current flow.
You definately dont want infinite resistance, as that indicates and
open...but if i remember correctly a good heating element on my dryer,
for example runs a few ohms resistance.

Please correct and cite me if im wrong...I could be..

Josh


SMS wrote:
wrote:
I have a Solar panel connected to the Immersion heater and recently the
water temperature has dropped dramatically even with the Immersion
heater on. I have removed the element from the heater but would like
to test whether the element is working. is there a simple way of doing
it? The pipe at the top of the tank seems quite warm but not sure if
thats the panel heating it up or the immersion heater. Thanks

Well it's easy to test if it's open, just use an ohm meter. The
resistance on a working heating element will be close to zero ohms.

Someone will correct me if I'm wrong, but I believe a heating element is
either good or bad, there is nothing in the middle, it's either burned
out, or it's good.

Testing the heating element in a water heater
 

If you have an open(no reading across the two terminals) on a VOM the
element is dead, you should get a resistance reading, depending upon the
wattage of the element. You could also apply 240 volts across the element
for about two seconds, and you'll know if its heating. You need to check the
thermostat on the heater, and if its a large tank it will have two elements
and two thermostats




wrote in message
oups.com...
I have a Solar panel connected to the Immersion heater and recently the
water temperature has dropped dramatically even with the Immersion
heater on. I have removed the element from the heater but would like
to test whether the element is working. is there a simple way of doing
it? The pipe at the top of the tank seems quite warm but not sure if
thats the panel heating it up or the immersion heater. Thanks

Testing the heating element in a water heater
 

Testing the heating element in a water heater
 

trainfan1 wrote:
wrote:

Actually wouldnt a reading of 0 ohms indicate a short? I thought the
way a heating element worked was due to resistance to current flow.
You definately dont want infinite resistance, as that indicates and
open...but if i remember correctly a good heating element on my dryer,
for example runs a few ohms resistance.

Please correct and cite me if im wrong...I could be..

Josh

I'm quite sure "a few ohms resistance" is pretty damn near "close to
zero ohms".

Sounds like you guys are in agreement here...

Rob

There is a very large difference between zero ohms and a few ohms,
zero ohms would draw an infinite amount of current. The resistance
should very low, i.e. around 12 ohms for a 3.8KW element supplied by
240V. I suggest you measure the resistance of the heating element and
then calculate the expected amp draw at the applied voltage. The
formula is voltage/divided by resistance or I=V/R (I is current). Then
find the KW by multiplying the voltage, the current, and the power
factor (I would assume .8) and then divide by 1000 or KW=V*I*.8/1000.
What you calculate should match the KW rating of the element. If it
does not there is a problem. I agree that heating elements usually
either work or they don't. I also agree with a previous poster that it
is possible to test on a bench by very briefly connecting a 220V or
110V source to test the element. The watchout is that the element will
heat up VERY rapidly and can cause an injury, a fire, or burn out the
element since it will not be immersed in water.

Testing the heating element in a water heater
 

trainfan1 wrote:
wrote:

Actually wouldnt a reading of 0 ohms indicate a short? I thought the
way a heating element worked was due to resistance to current flow.
You definately dont want infinite resistance, as that indicates and
open...but if i remember correctly a good heating element on my dryer,
for example runs a few ohms resistance.

Please correct and cite me if im wrong...I could be..

Josh

I'm quite sure "a few ohms resistance" is pretty damn near "close to
zero ohms".

Sounds like you guys are in agreement here...

Rob

There is a very large difference between zero ohms and a few ohms,
zero ohms would draw an infinite amount of current. The resistance
should very low, i.e. around 12 ohms for a 3.8KW element supplied by
240V. I suggest you measure the resistance of the heating element and
then calculate the expected amp draw at the applied voltage. The
formula is voltage/divided by resistance or I=V/R (I is current). Then
find the KW by multiplying the voltage, the current, and the power
factor (I would assume .8) and then divide by 1000 or KW=V*I*.8/1000.
What you calculate should match the KW rating of the element. If it
does not there is a problem. I agree that heating elements usually
either work or they don't. I also agree with a previous poster that it
is possible to test on a bench by very briefly connecting a 220V or
110V source to test the element. The watchout is that the element will
heat up VERY rapidly and can cause an injury, a fire, or burn out the
element since it will not be immersed in water.