CH Inhibitor - how much, when and where?

[Dave]

I'm doing lots of overtime at work but also trying to redecorate the whole house in my spare time. Over the last two weeks I've had three radiators off the walls to paper behind them, so that's three 'radiators-worth' of water I've lost out of the system and needed to replace over that period of time.

I'll not get any decorating done for the next seven days but then I'll be taking another rad off for a couple of days. I suppose, to cut the story short, I'll be losing nine rads-worth of water and replacing it again over a period of about three months in total, maybe slightly longer.

What should I do about inhibitor? When should I add it into the system? How much should I add in, and where? I've got a couple of 5ml syringes that I could use to squirt the inhibitor into the rads through the hole where the bleed valve goes after reconnecting them and before refilling them - would this be OK?

TIA Dave

[John]

Is the bleed valve in a screwed bung that can be removed with a square key? If so - I remove this whilst the radiator is still empty and pour in the inhibitor. refit and then turn on the valves. ( I pour it in using a bit of tube and a funnel))

[Roger Mills]

Is it a vented system? If not, what I'm going to suggest won't work - but otherwise, it will.

When I drain a radiator for decorating, I save the water in a bucket and then - when putting it back - tip the water back into the F&E tank immediately before bleeding the rad. That way, the inhibitor is preserved.

[TheOldFellow]

What I would do is wait until you are doing the last rad. After fitting, but before filling, put a bottle of X100 (or whatever) in first, through any available orifice (e.g. bleed hole fitting), then seal the orifice and fill as usual, assuming a sealed system (if it's a header tank, put the X100 in the tank before filling the last rad.)

AFAIK you can't easily overdose X100.

R. NB IANAP (I am not a plumber)

[A.Lee]

If it were me, I'd leave it until the 2 weeks before the last rad was meant to come off, then put a dose of system cleaner in. When you take off the rad, flush the system out. Refit rad, then put inhibitor in. If you only have tiny bleed screw inlets to the rad,then a 50ml syringe will work fine, I've done it a few times, takes 10mins or so, but does it without spilling any. Alternatively, inhibitor is available in sealant tube type tubes, so can be injected in with the usual sealant gun. If you have a header tank, it could go in there if you are filling a few rads at one time, though I tend to inject into a rad, as you know it will get all around the sytem then. Put the last 50ml or so into the header tank, then some of that solution should get into the feed pipe going to the boiler when you bleed the rads.

Alan.

[Dave]

Good idea Roger but mine's a pressurised system so your method won't work I'm afraid. Thanks anyway mate.

[Dave]

Thanks Alan and The Old Fellow, good ideas.

[Usenet Nutter]

When my boiler was installed the fitter put a filling point in where the flow pipe leaves the boiler ...Just remove the stop end and I have a piece of 10mm pipe with a funnel attached to add inhibitor when required .

[Toby]

When I have to get behind my radiators, I generally don't take the radiator off, so this method may help you...

Turn of the valves (Count the turns on the lock shield and write it down somewhere!) Open the bleed screw to relese any pressure, but then close the bleed screw (you shouldn't get very much water out, if any). put old towels around the valves and then undo the nuts about half a turn. lift the radiator off the wall brachet and then hinge it down so the top is now on the floor. Do up the nuts. Write the turns on the lock shield on the back of the radiator, so you can't lose it :-)

Water loss is very minimal.

You need to have some slack in the pipes that feed the radiator, and also you do end up with the radiator sticking out, but it is trivial to hook it back on again later.

Hope this helps.

Toby...

[Dave]

Thanks Toby, that's a great idea :-)

[Usenet Nutter]

I remember someone had the idea of a fitting that screwed on to the wall behind the rad and another to the rad and both were connected by a chain so you loosened the nuts and pulled it forward and it was held by the chain.....don't think it ever took off tho'

[John]

But if you remove it you can properly flush the radiator. I also like to rub them down with wet & dry and paint them when lying horizontal - (on the dining room table! )

[Usenet Nutter]

You spray paint them I take it ? LOL

[Toby]

Does someone have to hold the radiator for you, when you are lying on the dining room table!?

[John]

Very amusing image!

Seriously - I hate paint runs and also paint doors by lying the door across the table to paint it. The hard bit is resisting trying to re-fit the door whilst the paint is still soft.