Instructions for adding Inhibitor to a Boilermate III ?

Hello,

Sorry if this has been asked before but I carried out a search and could not find a guide for this process.

Looking for instructions on the correct way to add inhibitor to the bm iii system after draining it down at the weekend to replace the three port valve.

Draining was carried out via the hallway radiator.

There are 8 x radiators in total.

Is it just as simple as adding the required does into the top of the Feed and expansion system ?

Thanks in advance.

8 rads = 1 bottle (10 rads really)
The unit will need a bottle per 100 litres.
Drain water out, add protector into top tank.And re fill system
Mike