furnox

[brianwaring]

how do you put furnox into a central heating system with a combination boiler

[KARL]

Fernox probably supply the answer to this one in their literature, however, the question is whether the system is a closed one (pressurised to water mains pressure) or gravity pressure only (with an open header tank at the top end of the sytem). In the latter case you can simply pour the material into the header tank and let it gradually disperse into all the circulating fluid (water). In the former the advice commonly given is that you need to attach a special pump to a radiator vent and inject the additive into the circulating fluid. However, there is potentially another way using no special equipment which you are not likely to already possess: you can isolate a radiator by closing the valves on either side of it, drain the radiator in the usual way, then re-attach it to the valves and if the radiator has more than one plug at the top (this is where a double is advantageous, and some makes are better than others in this particular circumstance - some makes do not offer this possibility) you remove both and pour your additive in using a funnel and some tubing. Then you refit the plugs and open the isolator valves to refill the thing and allow the additive to be distributed around the system. Good luck.

[KARL]

P.S. I would like to add that it is nice to know someone wants to use additives in a system which presumably does not already have any. I regard it as bordering on being criminal when installers and maintainance people do not draw owners' and users' attention to the importance of using additives. In some areas corrosion and a variety of problems can be much reduced if not eliminated altogether by using the correct additives. If you are uncertain of the need for new/more anti-corrosion additives in your system then bleed off a small quantity of fluid from a radiator and put a piece of naked (i.e, not coated in any way, and not stainless) steel into it (a paper clip, nail, or best of all a small piece of steel wool) and leave it for a week at most. If it doesn't rust then there is probably enough additive in there already. Otherwise think about the cost of replacing radiators, etc. against the few pounds it costs to buy some additive. I have personal experience of Fernox and have found it entirely satisfactory. There are other additives apart from anti-corrosion, check with someone like Plumb Center who have Fernox's brochures.