How much CH inhibitor?

[olimain]

Got to fix a leaking pipe at my parents house so draining down the system. They've already had one blow off this winter and this one looks like it's close so I want to sort it out before it does!

As I'm draining down fully, roughly how much inhibitor should I be adding when refilling? It's a 5bed 4 bath new build, approx 14 rads & 3 towel rads. I was planning on 2 x 1L of Sentinel.

Thanks

Oli

[olimain]

Thanks, no nothing cast, house is only about 15 years old.

[olimain]

Thank you-the rads are all doubles so it sounds as though I should be fine with 2L