Immersion no voltage between live and neutral

[Lee Brittain]

Just looking for some confirmation before I fit a new immersion heater element.

My cylinder is not heating when using the immersion heater. I have checked with a multimeter and have voltage across live and earth, neutral and earth but not live and neutral .

I have checked at the switch where all is normal ( voltage across live and neutral , live and earth nothing neutral and earth )

I assume this intimates a short circuit meaning I need a new element ?

Sorry if a Noddy question

 

[JohnW2]

I assume this intimates a short circuit meaning I need a new element ?

I would have thought it more likely that you need a new (immersion) thermostat.

Kind Regards, John

 

[EFLImpudence]

Disconnect the wiring from the element.

If it is ok, you should have ~19Ω, if 3kW, between L and N of the element,
if that is the case then you should have
open circuit between both L & N and Earth.

 

[bernardgreen]

and have voltage across live and earth, neutral and earth but not live and neutral

If you have 230 volts between Neutral and Earth at the immersion heater and at the switch

nothing neutral and earth

then almsot certainly the Neutral connenction between switch and immersion has become open circuit.

 

[terryplumb]

if you do not have 230 volts between line and neutral ,on the load side of the switch ( when switch is in the on position ) the switch is faulty and needs replacing.

 

[JohnW2]

if you do not have 230 volts between line and neutral ,on the load side of the switch ( when switch is in the on position ) the switch is faulty and needs replacing.

That would be true - but, as I understand it, the OP has said that there is voltage (I presume he means ~230V) between line and neutral at the switch.

As I implied before, if the OP is measuring voltage literally at the element, then it would seem that a faulty (open circuit) thermostat could well be the problem.

KInd Regards, John

 

[terryplumb]

johnw2 ,he is no doubt measuring voltage at the L & N terminals on the supply side of the switch. he is getting 230 v at the element between N & E !! regards terry.
p.s. if stat is open circuit ,voltage at the element would not be present .

 

[Lee Brittain]

firstly thank you for the really quick responses.

looks like I was a bit of blunt tool apologies. when I initially thought I was getting no voltage across live and neutral I was picking up two live terminals. (I've removed a shelf now so I can see what I am doing.)

feed to switch 240v
load from switch 240 v
thermostat 240 v
element 240v
element 19.5 ohms

but the cylinder is not heating.

would that indicate thick limescale on the element?

thanks again and apologies for being such a numpty

 

[terryplumb]

well this is a new ball game !!! did you disconnect the conductors at the element when measuring resistance ? are you now saying you have 230 volts L to N at the element ?

 

[winston1]

would that indicate thick limescale on the element?

NO. The element will still heat, it's just that the heat would take a little longer to get to the water.

 

[Lee Brittain]

I have disconnected the cables going to the elements and checked the resistance which is 19.5ohms

yes now have the correct voltage across live and neutral.

 

[terryplumb]

voltage N to E at the element is,...??

 

[EFLImpudence]

If you have 240V between the element terminals and had 19.5Ω through the element then it should be working.

 

[Lee Brittain]

N to E is 3 volts

 

[terryplumb]

my thoughts too EFL.