I'm doing lots of overtime at work but also trying to redecorate the whole
house in my spare time. Over the last two weeks I've had three radiators off
the walls to paper behind them, so that's three 'radiators-worth' of water
I've lost out of the system and needed to replace over that period of time.

I'll not get any decorating done for the next seven days but then I'll be
taking another rad off for a couple of days. I suppose, to cut the story
short, I'll be losing nine rads-worth of water and replacing it again over a
period of about three months in total, maybe slightly longer.

What should I do about inhibitor? When should I add it into the system? How
much should I add in, and where? I've got a couple of 5ml syringes that I
could use to squirt the inhibitor into the rads through the hole where the
bleed valve goes after reconnecting them and before refilling them - would
this be OK?

TIA
Dave