Adding Inhibitor to a Combination Hot Water Cylinder Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[notveryhandy]

My son in law's CH and Domestic Hot Water system is different to mine in that he has a 'Flomax FM4736 210 Combination Cylinder of 210 litres capacity. I believe the company that manufactured the cylinder may no longer be trading, (IMI Waterheating Ltd). We wish to add some Inhibitor to the system. The header tank appears to 'sit' on top of and be fixed to the domestic hot water cylinder. Am I in order, please, to introduce the Inhibitor via the header tank on this combination cylinder. There is an isolation valve on the cold water inlet to the header tank which will help matters but I want to be absolutely sure this is the correct procedure. I am minded either to partially drain from a downstairs radiator with drain facility or from a drain cock at the boiler, wall mounted, in the garage. Many thanks.

[stoneyboy]

notveryhandy,
"Am I in order, please, to introduce the Inhibitor via the header tank" [u]NO[/u]
Buy some inhibitor in a tube which will fit in a mastic gun and dose the system through the vent on a radiator.
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[notveryhandy]

[quote="stoneyboy"]notveryhandy,
"Am I in order, please, to introduce the Inhibitor via the header tank" [u]NO[/u]
Buy some inhibitor in a tube which will fit in a mastic gun and dose the system through the vent on a radiator.
end[/quote]

Thank you. Were it that easy :( All the rads in the house are not, what I call, of conventional design, in that the only available orifice is the bleed valve itself. There are no blanking plugs or boss incorporating the bleed valve screw. Per chance I managed, yesterday, to track down the current manufacturers of this type of combination cylinder and had a very helpful chat to a guy in their technical dept. I now understand the workings of this type of combination cylinder and can confirm that the correct, and probably only way, to add inhibitor is to shut the cold water inlet to the integral header tank, drain off sufficient water from a downstairs radiator, introduce the inhibitor then allow the system to top up. Easy I know, but I had not come across this type of cylinder or system before and I wanted to make sure. (The system also has two separate pumps).

I have posted the result of my findings should any other person be faced with the same situation.

However thank you once again for your response.

[stoneyboy]

notveryhandy,
Just so you know for future reference the inhibitor is injected through the bleed valve - the last one I used was made by fernox - so yes it is that easy.
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