Hello,

I need to refill inhibitor again as there was quite a bad leak in the
system, I have bought Sentinel X100 concentrate (BTW it was quite
cheap at Homebase, Twelve forty nine only). However the instructions
differ slightly to the Fernox product I used previously.

The instructions state that you must depressurise the system if it is
a sealed system, I suppose this is to prevent the inhibitor spitting
back out which was rather messy with the Fernox product.
Can I depressurise by bleeding the water out of a radiator until the
pressure is 0.0 bar?. I don't mind doing that.