I need to top up the inhibitor in my system, after having drained down 
part of it for some radiator work.  However, I haven't a clue what sort 
of inhibitor is currently in there.  I suspect that it's a bad idea to 
bung in anything else without complete flushing out, in case of adverse 
reaction or something - am I right?

I'm very loathe to drain the whole system down as it's incredibly prone 
to airlocks (I once had to call out a plumber just to sort that!) so I'd 
really rather avoid that...

Thanks
David

On 16 Sep 2005 08:08:58 -0700, "Aidan"  wrote:


>
>Lobster wrote:
>> I'm very loathe to drain the whole system down as it's incredibly prone
>> to airlocks
>
>If it's such a big problem, you could connect a hose to it from the
>mains, via a pressure reducing valve (very important that) and a
>pressure gauge that is accurate. Maybe remove a rad to connect hoses.
>Run water at, say, 1 bar, up the flow & down return and to drain. Open
>& close valves on rads to ensure they get a thorough flush through.
>Half an hour or an hour should dilute the existing inhibitors to the
>point that only a homeopath would claim they'd have any effect.


ROFL
excellent I will need to remember that phrase.




>
>Shut drain valve, shut inlet valve, remove hoses. The system is full of
>clean water. Re-fit rad. Pour inhibitors of choice into empty rad, fit
>& close air vent, open rad valves, vent air, top up pressure.
>
>You'll get a small volume of air coming out of solution when the boiler
>heats the water up. Maybe heat the system up & vent this before adding
>inhibitors into the empty rad; this will minimize the depletion of the
>oxygen scavenger chemicals.