Radiator inhibitor query

gilesm89

Thanks for all your suggestions. I feel pretty happy with how to go about adding inhibitor now.
I actually don't need to drain the system for any work to be done. It's just that I don't know how much inhibitor (and what type is already in there).
The boiler itself was drained by an engineer to recharge expansion vessel but don't know if that's enough to justify adding more inhibitor or not. I'm also a bit paranoid about just adding some when I don't know what is currently in there.

fred246

The system is pressurised so you need an injector to add inhibitor. Injectors are expensive so filling with eezyfill is a cheap DIY alternative. So you take a radiator, close both valves and then drain some water out. You then open the bleed valve to check the valves are holding and let air out as you fill. You then use eezyfill to fill with a bottle of inhibitor. Close the bleed valve and open the valves. Then bleed any air out. Fernox will test a sample for you at a cost but I don't think it's critical. You are better off with too much than not enough. 

neilmcl

Why not contact them to see if a, they drained the whole thing and b, did they add any inhibitor afterwards. I doubt they probably did so it won't hurt anything adding another bottle into the system. TBH, you cannot really overdose with inhibitor.

nick74

I would doubt that they would've drained the entire system just to repressurise the expansion vessel. We've had this done on our boiler a couple of times over the years and they just shut the isolation valves off on the boiler and drained a bit of water out of the boiler itself. I would guess perhaps 2 or 3 litres at most. Not really worth worrying about in terms of diluting the inhibitor, but no harm in adding some more if you like, particularly if you've been having to top the water up in the past.. I've used the Fernox in an aerosol can which connects to the filling loop and found it quite easy to add to the system. 

gilesm89

I did ask the engineer and he said that he just drained the water out of the boiler - not the whole system. (And he did not add inhibitor).
I guess the amount of dilution of inhibitor may not be so great in that case. That said I have no idea when inhibitor was last added and how much.

nick74

You can't really add too much, and mixing different types does not appear to do any harm in my experience. If you've no idea whether any has ever been added in the past I would just bung some in.

grumbler

fred246 said:

The system is pressurised so you need an injector to add inhibitor. Injectors are expensive so filling with eezyfill is a cheap DIY alternative.

How many times does it have to be repeated that with a magnetic filter installed it's easy to add inhibitor withour any extra tools?

neilmcl

grumbler said:

fred246 said:

The system is pressurised so you need an injector to add inhibitor. Injectors are expensive so filling with eezyfill is a cheap DIY alternative.

How many times does it have to be repeated that with a magnetic filter installed it's easy to add inhibitor withour any extra tools?

Take it easy mate, he was simply offering an alternative approach.