Please can someone tell me 2 differences between a one way light switch and an isoltaing switch used for an immersion heater?

 

Wild guess with so little info:
A "one way light switch" breaks one side of the 2-wire line going to the heater. SPST
An "isoltaing switch" (isolating?) breaks both sides of the 2-wire line. DPST

Ken

 

Please can someone tell me 2 differences between a one way light switch and an isoltaing switch used for an immersion heater?

Is this a UK style residential hot water tank immersion heater?
Max.

 

Please can someone tell me 2 differences between a one way light switch and an isoltaing switch used for an immersion heater?

The current rating.
Light - low power.
Heater - high power.