Central Heating inhibitor help

[aveatry]

Hi All
I had a compleate central heating system installed 2 years ago - mains pressure non vented hot water.
I have had to remove 2 rads and install a new one in another room 2000x300 single 1000x600 single 600x1100 Double so I will be refiling the 3 above with new water.
My question is how much new inhibitor do I add to the whole system
Can I add too much
And as I do not know what is in there now- which is compatable with what or does it not matter

 

[Youllneverguess]

As much as you like. Although there is a sound argument for not needing any if the system is designed properly.

Now.

How many worms are going to pop out of that particular worm?

 

[petit_pablo]

Chuck a litre bottle in of whatever it was treated with on installation.

 

[aveatry]

Chuck a litre bottle in of whatever it was treated with on installation.

that is part of my problem as i do noy know what it was.--So are they all compatable