Combi boiler best way to add inhibitor

[Goldspoon]

Sorry if already on forum somewhere but could not find...

DRAINED SYSTEM

I have to drain my combi based system and add the inhibitor. I have been running with cleaner for a couple of weeks and I put this in via one of my new rad tailpipes.

But what's the best way of adding Fernox? I am considering making a place in the pipework for this purpose: my first thoughts are to add a T fitting into some vertical 22mm pipework and then add to this a short horizontal with a 90 degree bend so it then points upwards. On top I would add a compression coupler, then another short section of pipe with a bleed screw on top. To fill a drained system I could then take out the top "bit of copper with the bleed screw" and just pour Fernox into the top of the compression fitting. Then when I switch refill system with water I use the bleed screw to make sure no trapped air in "filling bit" that sticks up.

Is this a fair method?

UNDRAINED SYSTEM

Next week am adding inhibitor for a mate. I do not really want to drain down.

But how should I add the inhibitor? I know I can buy the Fernox cartridge gun kit and am considering this but at £28 (B&Q price) it is a bit steep really. Having never tried it... is it a good method? I read that you can use this to fill at the filling loop but I am struggling to think how - how does that work? I have read the instructions but they just detail the rad method.

If one has a container of Inhibitor and not the cartridge system how does one get this in without draining - or is that not possible?

Thanks in advance...

 

[cross thread]

drain a small radiator and fill it with inhibitor then turn rad valves on and vent /repressurise system

 

[ChrisR]

If you have a ladder type towel rail they often have plugs in the top. Some rads have large chrome plugs with the vents in the middle - they make it easy too.

 

[Goldspoon]

I tried filling a rad (with system drained) but got into all sorts of probs. When you look into the hole the route quickly turns right. When I poured it in via a funnel it just all came back out again. So I bought one of those silly things with a black balloon hand pump and two thin clear pipes. Idea is you use it one way round to remove a pint of water and then other way round to inject the inhibitor in. Even the thin 5mm plastic pipe would not go in rad, turn right and get itself into rad - so when I pumped it all came back out the hole and it was all turning messy!

Am I missing something here?

 

[Goldspoon]

Thanks... but don't have one

If you have a ladder type towel rail they often have plugs in the top. Some rads have large chrome plugs with the vents in the middle - they make it easy too.

 

[Chris_J]

I used a tube with a funnel on the end. The end that went into the rad, I sealed with a bit of duct tape while I filled it to stop it pouring out.

Forget all these injection kits, you don't need them. Fleabay is good for cheap inhibitor. I got X100 for £5.

 

[Goldspoon]

Thanks all...

Chris_J I'll knock something up - was heading down that line of thought myself. Might try something diff to tape though!

 

[Bahco]

Fleabay is good for cheap inhibitor. I got X100 for £5.

Probably 90 % water for that money!

 

[Chris_J]

Lol yeah I wouldn't be suprised!