LED for electric heater (UK)

[R791945]

I have done some continuity testing and I find that the thermostat receives the supply first. This is then passed through the rocker switch and on to the heating element.

I half suspect a couple of 240v relays might work if limited to one rocker switch but I do not have a clear picture how to do it.

I think what I would need to do is every time the thermostat turns off, the rocker switch should be isolated from the heating element and the supply from the thermostat. If the RSw is off: LED off , If RSw on: LED on.

 

[Alec_t]

Couldn't you just use piggy-back Lucar connectors to connect the neon between Neutral and the Line side of the thermostat?

 

[R791945]

Couldn't you just use piggy-back Lucar connectors to connect the neon between Neutral and the Line side of the thermostat?

This will not achieve what I want. I need to know if I have left on the rocker switch which may not be lit up because the thermostat is off whilst the temperature in the room is more than the thermostat's temperature setting. Hence the reason for suggesting relays in my last post.

 

[kellys_eye]

Wire a neon across the thermostat. It will be out when the heater is on -shorted by the thermostat contacts (but the rocker switch neon will be on then anyway) and 'lit' when the thermostat is open circuit.

 

[flippineck]

Wire a neon across the thermostat. It will be out when the heater is on -shorted by the thermostat contacts (but the rocker switch neon will be on then anyway) and 'lit' when the thermostat is open circuit.

reminds me of how a fish tank heater I once had, worked. neon seems a good idea to me..

 

[R791945]

Wire a neon across the thermostat. It will be out when the heater is on -shorted by the thermostat contacts (but the rocker switch neon will be on then anyway) and 'lit' when the thermostat is open circuit.

Does this idea work when the thermostat is off because the room temp is higher, and the rocker is switched on but has no current because it is not being supplied from the temporarily off, thermostat?

 

[kellys_eye]

When the thermostat is 'off' the neon will be lit (but the rocker switch won't) and vice versa. You will always have an indication of power being applied - which is, I believe, what you're trying to achieve?

 

[R791945]

When the thermostat is 'off' the neon will be lit (but the rocker switch won't) and vice versa. You will always have an indication of power being applied - which is, I believe, what you're trying to achieve?

My aim is to know if the rocker switch is in the on position when no power is coming from the thermostat, It is not obvious because the neon in the rocker switch will be off.
In other words when I go to bed, have I left the rocker switch on so that during the night an empty room will be heated by the radiator as and when the temperature drops below the thermostat setting?

 

[kellys_eye]

Wired as I suggest there will be ALWAYS be a light on if power is applied to the heating element. It could be the rocker switch light or the thermostat light but ONE of them will be on.

The heater will only ever be 'safe' when ALL the lights are off.

It doesn't matter how the thermostat is set, the only way to get all the lights off is to have the rocker switch in the off position.

 

[R791945]

Wired as I suggest there will be ALWAYS be a light on if power is applied to the heating element. It could be the rocker switch light or the thermostat light but ONE of them will be on.

The heater will only ever be 'safe' when ALL the lights are off.

It doesn't matter how the thermostat is set, the only way to get all the lights off is to have the rocker switch in the off position.

Let me understand how you recommend the wiring:

Wire a neon across the thermostat. It will be out when the heater is on -shorted by the thermostat contacts (but the rocker switch neon will be on then anyway) and 'lit' when the thermostat is open circuit.

Are you proposing that I short the thermostat from its live supply to the output feed? So even though effectively the same wire is being bridged the neon will light up if the rocker switch is on because the circuit will be completed through the heating element?

 

[(*steve*)]

Nothing will be shorted.

The neon indicator lamp (with its accompanying resistor) will be placed across the thermostat.

When power is applied to the heater and the switch is on, the heating element will me supplied with power either through the thermostat (turning on the main power light in the switch) OR it will be supplies with power via the neon indicator.

When powered by the neon indicator, there will be insufficient power to produce any heat, or to light the indicator on the power switch, but the indicator across the thermostat will illuminate

Thus, if either indicator is lit, power is applied to the heater and it is either heating or ready to when the temperature drops.

 

[R791945]

Nothing will be shorted.

The neon indicator lamp (with its accompanying resistor) will be placed across the thermostat.
.

Thank you for the detailed explanation. I understand it much better.
Will the resistor be built into the neon indicator lamp I buy, so that I do not need to buy a separate resistor?

 

[(*steve*)]

If you purchase a neon indicator that is specified for your mains voltage then it will have an appropriate resistor built-in.

This is NOT what you want. In this case they suggest the resistor you would need for 240V.

This would be appropriate. You will note that it is rated for (in this case) 220V.

 

[R791945]

Thank you every one for helping me find a solution.

If I find an LED indicator rated for 240v will that work just as well as the Neon?

 

[Bluejets]

Usually any 240v rated LED will come with a high price tag.
I've seen Clipsal units at $40.00.
Neon units come in at maybe $3 or $4 depending where you get them.
Neon is about 10 cents and a resistor maybe 10 for 10 cents.