Immersion heater not heating

[Adrian Morris]

Hi.
Newbie hear. Having problems with immersion heater not heating.
Put new St/St tank in loft to replace old square one with lift up lid.
Immersion heater worked fine on old one with short heater on 13A fused switch.
New one kept blowing fuse so changed to 20A double pole switch.
So far so good.
Turned it all back on nothing blew but not heating. Checked wiring again all ok. Set stat to 65deg. Pressed reset. Turned back on still not heating.
Any suggestions.
It's a Tesla Incoloy 18".

 

[andyb]

There's nothing anyone can do to help you here Adrian, you need an electrician to visit you and test the immersion and supply to it.

 

[Taylortwocities]

@Adrian Morris Do you have a two-probe voltage tester, or a multimeter? Do you know how to use them?
If the answer is no, then you need an electrician.

If you do have the right test equipment then just changing random things, reseting something and hoping isn't a great way to spend a Saturday.
Use your test equipment to check that there is 230volts between the neutral and live into the immersion housing. Then its a simple job to check the 230V as it passes through the thermal reset, and the the thermostat to the immersion element.

Still got 230v all the way through? Probably the element. What's the resistance of the element?

PS. WTF is a "St/St tank" I guess thats stainless steel? Is this an unvented hot water tank??

 

[telectrix]

might be stainless steel as opposed to Pl/Lk (plastic leaky).

 

[Adrian Morris]

Hi.
Yes. Stainless Steel. Sorry. Mechanical Engineer speak.
Have got a cheap multimeter does V, A and Ohms.
Will do some checking.
Wierd though as the Immersion heater is only 2 weeks old and have rewired from the new 20A double pole to Immersion heater.

 

[DefyG]

Has it tripped out on 'overtemp'.
Is there a reset button on the stat?
Possible set too high and tripped out if got too hot!

 

[Adrian Morris]

I think it's all sorted now.
After doing a continuity test and a power test. It seems like a crap design on the reset button.
Instead of sitting flush then popping up it sits below then pops up level which confused me a bit till I poked it down due to no ohms in the thermostat.

 

[SJD]

I think it's all sorted now.
After doing a continuity test and a power test. It seems like a crap design on the reset button.
Instead of sitting flush then popping up it sits below then pops up level which confused me a bit till I poked it down due to no ohms in the thermostat.

I find that if a thermostat overheat has operated, after resetting there is a fair chance it will operate again when the tank has heated up again. Typically I'd replace the thermostat.

 

[davesparks]

Immersion heater worked fine on old one with short heater on 13A fused switch.
New one kept blowing fuse so changed to 20A double pole switch.

What type of circuit is this connected to and what rating is the MCB feeding it?

Generally speaking replacing an SFCU with a DP switch because the fuse is blowing is akin to replacing a blown fuse with a nail and calling it fixed.

 

[Adrian Morris]

Working at the moment. Any problems should trip the 16A mcb. I'll see how it goes.

 

[snowhead]

Instead of sitting flush then popping up it sits below then pops up level which confused me a bit till I poked it down due to no ohms in the thermostat.

It's not Crap design, it's a Safety feature to stop it being easilly reset. (without further investigation as to the cause)