Immerser heater - how do I switch it on?

[MoonMan2]

I have a fuse for it on the consumer unit.

I have an immerser switch in the kitchen with red light indicating on/off.

I have a switch at the hot water tank itself which connects via cable to immerser at top of tank.

I have switched all of these to on, yet nothing.

I of course use the gas to heat the water, but I presume I should expect the immerser to work too.

 

[seco services]

I'd start by checking which if not both switches get power from the main fuse.
Then check the 13 amp fuse in the fcu.
and work your way to the immersion.

Does the one in the kitchen light when turned on ?

 

[muggles]

Could be on Econobmy 7 possibly, IE it only works at night??

 

[Diyisfun]

If the water in the tank is already hot, ie from the boiler, then the imersion t/stat will not let the heating element on.

 

[muggles]

Or alternatively the immersion thermostat high-limit could have tripped out

 

[xr4x4]

That's a point, how do you know it's not working?

 

[MoonMan2]

Good points made by all.

The red light next to the immerser switch lights when switch is on. When I switch off the immerser switch (MCB?) in the consumer unit, this red light goes off.

I left it on all night and nothing happened.

muggles, how do I reset the thermostat, that is if it has tripped?

 

[seco services]

Resetting the stat.
Look on the stat where the arrow is pointing for the reset switch
could be white/black.

On some others like the backer the overheat is seperate, it's the red button.

Failing that check with a multi meter that the power is getting to the immersion.
If power is getting to the immersion check the element for resistance

 

[xr4x4]

Good points made by all.

The red light next to the immerser switch lights when switch is on. When I switch off the immerser switch (MCB?) in the consumer unit, this red light goes off.

I left it on all night and nothing happened.

muggles, how do I reset the thermostat, that is if it has tripped?

I guess your switching the 'gas' off and your trying to heat the water via the immersion?

So I'm guessing the hot water is cold at night and the immserion doesn't heat it up over night?

 

[MoonMan2]

Here are photos of the unit:

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• MoonMan2
• 15 Jul 2011
• 1

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• MoonMan2
• 15 Jul 2011
• 1

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• MoonMan2
• 15 Jul 2011
• 1

I can't find a reset switch anywhere.

I used an ac voltmeter and can confirm that between the live (brown) and neutral (blue) I was getting 230V ac. The live wire goes into the blue thermostat device and has a white wire output, which I presume is the supplier of the current to the element. When the probes of the voltmeter were across the metal contacts of the white wire and the neutral it read 0V regardless of what value the thermostat was at via rotating with screwdriver.

 

[seco services]

So you have now proved the stats no good. (thats only a 7" stat should be 18")

Check the element for resistance. with mains power off.

 

[MoonMan2]

With ohmeter set to read upto 200 ohms, It read 0.4 ohms across the element.

 

[seco services]

Should be around 19 ohms.

 

[MoonMan2]

Got it at 20ohms, had the pins of the ohmeter across the wrong bit of the element. I tried connecting the live wire directly to the element (bypassing thermostat) and the element heated up the water no probs.

So just replaced thermostat with one from B&Q and voila - it works perfectly !!!

Thank you so much to everyone in particular to "seco services" - you should charge money my friend

 

[seco services]

Hope you got the right size.
Glad it's sorted.