Adding an Inhibitor to C/H System

alared

Hi all,some advice appreciated.

I would like to check my C/H system to make sure there`s enough anti -corrosion fluid in it.
I`ve read to take a sample from one of the radiators and put a nail in it and if after a few days if it goes rusty,that`s a sign that more inhibitor is required.

The other question is, if more is needed, what`s the proceedure.
In my loft I have a large water tank and beside it a smaller one which I assume is the tank that tops up the C/H system.
Is it just a matter of adding the inhibitor to the small tank?

latecomer

when I did it tied up the ballcock from the tank and then drained some of the water out of the system so that the tank was empty. Then I poured the inhibitor into the outlet pipe (as far as possible) and then let the tank fill back up. I then drained more out of the system so that the inhibitor was pulled down from the pipe into the actual system.

keystone

If you aren't getting gas in your rads or an increase in boiler noise theres a fair chance that its OK. When was it last added? A system shouldn't be overdosed.

The simplest way is to introduce it through a radiator having drained some water out first. Putting it in the header tank doesn't always ensure that it fully gets into the system.

Cheers

SplanK

I tired to add inhib via a rad with one of those injector cartrages... what a mess that made - next time im filling via the header tank....

as above... drain some of the rad system down, add it to the header tank and refill is much easier if you can get to your header tank

alared

keystone wrote: »

If you aren't getting gas in your rads or an increase in boiler noise theres a fair chance that its OK. When was it last added? A system shouldn't be overdosed.

What I`m concerned about is that last July whilst having the bathroom completely done, the plumber had to drain the system to change the valves on the bathroom radiator,which he had removed to tile behind.
When he refilled the system I don`t know if he added inhibitor or not and that`s why I want to check it.
The Ch seems to be running OK and the boiler no more noisy than in the past.
Should I do the nail test to be sure?

keystone

SplanK wrote: »

I tired to add inhib via a rad with one of those injector cartrages... what a mess that made - next time im filling via the header tank....

Waste of time and energy IMHO and expensive too. Drain some water from rad. Remove blanking plus at opp end to bleed valve. Screw in male ½" elbow. Pour it in. Replace blanking plug. Job done.

as above... drain some of the rad system down, add it to the header tank and refill is much easier if you can get to your header tank

OK but as I already said you cannot guarantee to get it all into the system that way and you'll be taking at least twice as long to do it that way as doing it via a rad.

HTH

Cheers

keystone

alared wrote: »

What I`m concerned about is that last July whilst having the bathroom completely done, the plumber had to drain the system to change the valves on the bathroom radiator,which he had removed to tile behind.

The whole system or just as far down as the bathroom rad valves?

When he refilled the system I don`t know if he added inhibitor or not and that`s why I want to check it.

He should have done if he completely drained it. Have you asked him?

The Ch seems to be running OK and the boiler no more noisy than in the past. Should I do the nail test to be sure?

Up to you. I've heard of this "nail test" but not convinced its any good. The solution would seem to be:

1. Ask him what he did.
2. If he only drained down to upper floor level and put no inhibitor in then give it half a dose.
3. If he drained the whole thing and put none in give it the whole lot.
4. If he added an appropriate amount of inhibitor however far he drained it do nothing.

Cheers

alared

Cannot contact him,left the area.
He drained out completely from the rad in the hall.
The house has 11 rads,would 500ml be sufficient if needed?

keystone

alared wrote: »

Cannot contact him,left the area.

Oh.

He drained out completely from the rad in the hall.

Silly s.d!

The house has 11 rads,would 500ml be sufficient if needed?

No. You'll be wanting a tad over a litre - prolly get away with a litre if rads are relatively small. If you have a number large panel rads stick 1½ litres in. (I'm assuming X100 BTW)

Cheers.