Original HW thermostat as safety cutout

[HughJ]

Hi, how do I wire the original HW tank thermostat as safety cutout? I've got nothing wrong and the system has been running for a long time but I remember reading I should really use the original thermostat (touching tank in cutout) for safety.

Thanks

[Richard]

I'm going to be honest, this is a question that doesn't get asked because if you don't know the answer you are not qualified enough to do the works.

Unvented cylinders come under G3 regulations of which an installer has to be qualified on to do any such works on. So if you do not have your unvented cylinder ticket, please find someone who does and they will know the answer (and do the works for you).