Fernox Rust inhibitor or whatever it's called

[AK]

I have been trying to bleed my radiators tonight and the top floor (a

3 story house) is just about as full of air as it could be. I have bled loads out but after running downstairs 3 or 4 times to top up the pressure in the system I have given up for the night. It occurs to me that I am probably getting this because I don't have enough (if any) treatment in the system. the house is 18 months old and I would bet the developer didn't put anything in....................the water is nice and clear what is coming out.

I would like some advice as to what I need to put in - I have to replace one of the bleed valves (if that's not what they are called I would appreciate knowing what it is called so I don't look silly when asking for one!) as it doesn't tighten properly and I understand you can put it in to the system that way - perfect as I have so much air space in there!!

Any tips gratefully received

Angela

[IMM]

Most new houses have a 12 month guarantee on all fittings. Check this out. If you suspect you have no inhibitor Sentinel X-100 for instance, then partially drain, install X-400 sludge remover, and then after removing after a few weeks in the heating season flush out twice and fill with X-100. Best do it now before corrosion takes hold.

[AK]

removing after

X-100. Best

that's a bit more extreme than I intended! The water that comes out is completely clear so is it likely there is any sludge to remove? it's only had 1 winters use.

[chris French]

In message , AK writes

Good old IMM

If the water is clear then it indicates that there almost certainly was some inhibitor in there (the stuff I have had is clear IIRC) I'd have thought as IME you can get some coloration at least quite quickly - certainly after a year. You get a black coloration in the water from the corrosion products.

Anyway, no I wouldn't think sludge remover is worthwhile here. But it will be worthwhile adding some inhibitor anyway, then at least you know that has been done properly.

Add some Fernox or Sentinel inhibitor from your local DIY shed or Plumbers Merchants.

If you have an open system with a header tank you can just add it to there.

Fernox do one in syringe that you can use to inject it into a rad. I fitted a suitable threaded fitting to a piece of Hep2O pipe (flexible plastic pipe), threaded that into the threaded hole at the top of the rad, funnel in the end and then pour it in.

If you have a column type rad in the bathroom with the bleed valve on top you can just stick the funnel in the top of that.

[IMM]

Corrosion could have taken hold in that time, and almost certainly seems that way. When corrosion is occurring hydrogen is produced. many think it is just air.

[John]

L O L

Why didn't you use the bleed valve adapter and short length of flexible tube which comes with the tube of Fernox inhibitor? The instructions are on the tube and all that is required extra to the Fernox kit is a skeleton mastic gun to "work" the tube of inhibitor.

SNIP

[Dave Plowman (News)]

If you've got that amount of air - or gas - in a sealed system that's only

18 months old, you've got a large leak somewhere. Unless some work has been recently done on it?

[IMM]

Our resident unqualified Corgi man laughed at that? He is making this up, or needs attention.

[adder]

What pressure do you run the system at? It would seem to me that the rpessure reading at the bottom of the hosue would be mroe than the one at the top so maybe air is being drawn in through your leaky bleed vave?

[chris French]

In message , John writes

Ahh re-reading that I did give the wrong impression.

I didn't actually use the Fernox syringe stuff, I just used normal in a bottle stuff.

[AK]

I have replaced the leaky bleed valve now (I was quite impressed with myself that I tackled that one!), so we'll find out if that cures the air problem The guy at the plumbers merchant said he didn't believe in inhibitor, but If I wanted to put it in I should use the same brand - but I don't know what might be in there already!!!. so it looks like a system drain down may be in order. I have to get the boiler serviced - I might find how much it would cost to get the whole system sorted - anybody know any good plumbers in or around Eastbourne????

Angela

[Andy Hall]

Plumber's merchants are full of old wives and their tales - on both sides of the counter. It is always a good idea to use inhibitor.

If I were unaware of what is in the system, I would be inclined to drain it down and start again. It doesn't matter within reason if you overdose, though.

Do be careful if somebody offers you a powerflush. Typically, prices north of £500 are charged. You can rent the equipment and DIY it for a lot less.

Avoid BG unless you are feeling rich.

.andy

To email, substitute .nospam with .gl

[Ed Sirett]

On a sealed system it is not likely that corrosion from oxygen could have gone very far in only 18 months, even if there was a mechanism for air ingress. The 'air' might indeed be hydrogen from anaerobic corrosion caued by acid flux residues.

On a brand new system it is quite conceivable that not only was inhibitor left out but also that flux residues have been left in.

To be absolutely sure that all was well, I would drain, add a 'new' system cleanser like Sentinel X300, run for few hours, drain, fill with inhibitor (Fernox, Sentinel or whatever).

See my FAQ on Sealed CH and especially on getting the air out.

[John Stumbles]

The bleed valves are the ones at the tops of the radiators which you open to let air out. I've never seen one fail though. They're not all the same size: some have just the little pointed-ended screw going into a threaded hole in the steel of the rad itself, on others the ponty screw goes into a brass (or chromed) bush which screws into a bigger hole in the rad. Usually these bushes are the same size as the screw threads of the rad valves, and there's a blanking plug at the other end of the top of the rad (so the rad has four same-sized threaded holes, at each end, top and bottom). Best to take the radiator along to the plumbers' merchants ;-)

The stuff you get to squirt in through the bleed hole costs an arm and a leg: better to get ordinary liquid inhibitor. If you have a partly empty radiator (you can turn off both valves and loosen one valve-to-rad connecting nut to let out water) and the sort of bleed valve in a bush that's the same size as the valve threads then you can unscrew the bush and pour in your inhibitor using a tube and funnel or squeezy liquid bottle etc. Otherwise a pump-up garden sprayer adapted to fit the filling hose for the system can be used to squirt in liquid inhibitor (assuming you have a filling hose rather than special filling key).

Use Fernox MB1 or Sentinel X100 not Purimachos Protex.