Immersion tank half filling

[Gruffalo]

Basically the header tank above the immersion is working as it should and I proved it by filling it to the overflow with a hose yet the cylinder below still only fills to half way which has caused the wring for the thermostat/element to burn out.
What could be causing the immersion to only partially fill and what stops a fully functioning one stop filling?

Cheers

 

[John D v2.0]

Blockage in the pipe from the bottom of the header tank to the cylinder

 

[denso13]

What could be causing the immersion to only partially fill

Storage cistern emptying or blocked feed. Do you have water coming out of your hot taps?

 

[Gruffalo]

Thanks for the replies and excuse any terminology I use, newish to heating.

I thought of blockage so emptied the immersion tank then allowed the header to refil which it did but only halfway unless it could be a partial blockage?

Cistern fills as it should and have hot water when the heating is on just not when I use the electric as the thermostat rod isn't in the water so doesn't get a temp reading and element is on constantly.

 

[John D v2.0]

How do you know it's only half filling? The hot water draw off should be at the top.

 

[Gruffalo]

How do you know it's only half filling? The hot water draw off should be at the top.

It is but when pulling the thermostat out, it's bone dry

 

[bernardgreen]

the wring for the thermostat/element to burn out.

The thermostat is almost certainly fitted into pocket and not in direct contact with the water in the cylinder. Therefore it will be dry even if the cylinder is completely full of water.

The wiring will be burnt if the current to the immersion heater is too high for the wiring. or the wiring is too small for the heater's current or a terminal has become loose.

If there was no water around the immersion heater then the immersion heater would get hot and trip the thermostat which would stop the current flowing.

 

[denso13]

which it did but only halfway

What filled halfway? The hot water draw off is at the top of the cylinder so it must be full if you have water at the hot taps.

 

[HERTS P&D]

Every day is skool day!

Andy

 

[Gruffalo]

I think you're right about the pocket, I keep looking at heating elements thinking the rod is the actual thermostat when it must be a slightly bigger tube the thermostat sits in, hence why it's not sealed, I did wonder why water didn't come out of there, I assumed the water outlet had a pipe that went into the cylinder.
So it must be full if I'm getting water out then?!
The reason the wiring could have burnt out then could have been due to faulty thermostat keeping the element constantly on?

 

[Gruffalo]

Every day is skool day!

Andy

Indeed!

Made myself look stupid but established the elements not boiling dry
Hopefully swapping that and the thermostat should give me hot water again.
The wiring in question:

 

[slippyr4]

If the immersion heater was boiling the water in your cylinder dry, you'd definitely know about it.

 

[Nige F]

Never mind about looking stupid I found a setup giving problems like yours - and the cold feed went in the TOP of the tank and the "hot" water came out the bottom The diy'er wondered why immersions kept burning out - the element was running dry in that setup.

 

[stardanny]

Poor connection.

Replace the thermostat with new thermostat with a build-in safety cut out, cut back flex and remake connection or renew flex with heat resistant 2.5mm2.

Daniel.