Honeywell T70 Hot Water Cylinder Thermostat wiring question

[ap222]

Dear all,

I have fully pumped hot water system with a Honeywell T70 Cylinder Thermostat and a Honeywell 3 port diverter valve (V4073A).

I was inspecting the wiring and noted that earth wire from the T70 cylinder thermostat is connected to a brown wire (I presume its Live) going to a Potterton timer (EP6002), and also to a grey wire (Live) going to the 3 port diverter valve.

Is this correct? Shouldn’t the Earth of the T70 be connected to the earth in the rest of the circuit?

I will kindly appreciate any clarification on this.

Kind regards

 

[heatserve]

In your case it's purpose is to carry a switched voltage when the hot water demand is either satisfied or not required.

If the cylinder stat is of plastic construction then an earth is not usually required.

Most installers would use 3-core flexi and sheath the earth wire in red to denote a switched live.

 

[ap222]

Thanks for the quick reply heatserve. That now makes sense. The Thermostat is made of Plastic & I'LL cover the wire with red tape.
regards