"Kevin Brady" wrote in message
...
Couple of months back I had to drain the CH system to remove an existing
radiator and cap off the flow & return, while extension works (new kitchen)
are being carried out. When refilling the system, although I had a bottle of
Fernox (about £15), I thought I wouldn't put it in for a couple of months,
until I had refitted the radiator and added one in a new location, which
would involve draining down alll over again, and wasting the inhibitor.

Did you actually completely drain the system, or would some water have remained?

If so you may still have some inhibitor.

My system survived a number of years without new inhibitor. Certainly much
longer than I intended!

There was very little sludge in the bottom of the radiators when I did get
around to drains and re-filling the system.

--

Michael Chare