?topping up ch sysrem with corrosion inhibitor

[stronach]

About 4 years ago I drained my ch system (conventional boiler) completely, flushed out all the rads and filled up again with corrosion inhibitor added. The system at that point was 15 years old. After about 1 year the 3 way valve packed up and the repair man drained some water off to below the valve level in order to change it. The valve was in the airing cupboard on the first floor of my standard house. System topped up, valve didn't work properly so on another visit previous events repeated. So corrosion inhibitor must have been diluted somewhat. I mentioned this to the engineer but he said there would have been enough left in the system to do its job ok. Now there is air forming in the system requiring bleeding on a weekly basis so corrosion must be occuring again. My question is if I take the water out of the f and e tank as far as the outlet pipe to the system then drain off 500 mls from a downstairs drain tap, then add 500 mls of inhibitor down the outlet pipe in the tank, will it find its way around the system eventually? This seems to me to be an easier solution if it will work. Any advice would be welcome.

[htg engineer]

Have you thought about adding a MagnaClean? this removes deposits from the system and has a dosing point incorporated.


http://www.screwfix.com/p/adey-magnacle ... AodGXwAKA#

Shop about you'll get one slightly cheaper.

htg

[stronach]

Thanks for that info, I have never heard of them, the Fernox TF1 seems to get better reviews on the screwfix site. What do you think of that one. Where on the system does it fit? As you can tell I don't know much about plumbing. Have used this forum a few times for advice and there always seems to be someone like yourself who helps me out. Thanks again.

[htg engineer]

It'll be the same principle as the Magnaclean, they say you can fit them anywhere on the heating system. Magnaclean says the best place is on the main heating circuit between the last radiator and the boiler.

I would fit it on the return pipework as close to the boiler as you can, the idea is that this trap any sludge/debri before it gets into the boiler heatex/workings.

htg

[stoneyboy]

stronach,
You should still top up the corrosion inhibitor as you describe but try to use the same make that you added originally.
end

[stronach]

Thanks for advice everybody, just need to do it now.