Christian McArdle wrote:
Building Regulations Part G3
3.3 To meet the requirement a directly heating unit or package should have a
minimum of two temperature activated safety devices operating in sequence:


Now I am well confused.

I was trying to put it right as per the manual.

Surely those regs mean the two stats on all unvented tanks (I.e hi stat
and control stat)

I looked up 5 different wiring diagrams for unvented cylinders none of
them have 2 valves - all have one from the time switch - all of
them have a built in thermostat (and a high limit stat) .

Any web references to wiring diagrams with two valves?