Adding inhibitor to central heating system. UPDATED

Belenus

We have a 16 year old Potteron Powermax HE150 condensing (not a combi) boiler with 12 standard radiators with TRVs fed by copper pipe from the boiler and 10mm plastic pipe from manifolds to the individual radiators. The boiler has an integrated 150 litre hot water tank. It was all installed in a new build in 2004/5,

The system works just fine. It heats the water and the house up quickly and there are no cold spots in any of the radiators. I occasionally have to top up the system pressure but not very often. I have never had to bleed air from any radiator in the ten years we have lived here.

It is at least three years since any inhibitor was added and possibly a lot longer. I have perhaps been remiss in not doing something about that sooner.

I have just drained a small amount of water from the bleed valve at the top of one radiator. The water is crystal clear with no smell and no taste on the tip of my tongue. That to me suggests that there is little or no inhibitor left but I am no expert. I have not yet drained water from the bottom of a radiator where sludge might have accumulated.

Is there an easy DIY test I can do on the water? Perhaps seeing if a nail rusts in a glass of it or something similar?

Should I add inhibitor anyway and what is the best product? I presume that I can add it via a bleed valve.

Thanks.

fenwick458

yes definitely, get some more put in. I think you should just put in a bottle every year. I empty out and clean the "Magnaclean" I have fitted and then pour the solution into there once a year

FreeBear

Belenus said:  I presume that I can add it via a bleed valve.

Trying to get enough inhibitor in to a heating system via a bleed nipple is going to be a very long and pointless task. On my radiators, the bleed nipple is mounted in a 1/2" BSP bung at the top of the radiator - After draining some water out, I'll unscrew the bung and add the inhibitor through the hole.

On a sealed system, I would expect there to be a dosing point (filling loop ?) specifically for adding chemicals - Check your manual and pipework close to the boiler.

For vented systems, adding inhibitors to the the header tank (after draining some of the water out from the system) is by far the easiest method.

Jeepers_Creepers

A 16-year old boiler and 10mm pipework?

Belenus, please do yourself a giant favour and install a magnetic filter - Magnaclean or Fernox or whatever the best one is these days - on the return pipe to the boiler. Once you do this, it'll not only start to collect any sludge forming in your system (anathema to microbore pipes) but be a breeze to add anything you need to from now on - inhibitor certainly, and perhaps later system cleaner and sealer...!

Belenus

Update:

I bought a cylinder of Fernox F1 Express and injected it via the filling loop today so thanks for the above advice and suggestions.

J-C, I will get a Magnaclean or suitable similar filter installed. It is a bit tight for space inside the boiler housing but I suppose the return pipe can be rerouted outside the casing and in again as there is plenty of room on either side.

Thank again everyone.

neilmcl

Belenus said:

Update:

I bought a cylinder of Fernox F1 Express and injected it via the filling loop today so thanks for the above advice and suggestions.

J-C, I will get a Magnaclean or suitable similar filter installed. It is a bit tight for space inside the boiler housing but I suppose the return pipe can be rerouted outside the casing and in again as there is plenty of room on either side.

Thank again everyone.

You can fit the filter anywhere on the return, doesn't necessarily have to be anywhere near the boiler itself. Mine's upstairs under the bath 😉.

Jeepers_Creepers

Belenus said:

Update:

I bought a cylinder of Fernox F1 Express and injected it via the filling loop today so thanks for the above advice and suggestions.

J-C, I will get a Magnaclean or suitable similar filter installed. It is a bit tight for space inside the boiler housing but I suppose the return pipe can be rerouted outside the casing and in again as there is plenty of room on either side.

Thank again everyone.

Yes, a couple of elbows needed to crank the pipe away to the filter is pretty common.