Cheap inhibitor causing air?

[Ltnman]

I had the boiler replaced with a combi 8 months ago. Since then on three occasions I have had to bleed three different upstairs radiators, the latest one being yesterday.

The installer used an inhibitor called Tradesales and not the normal recommended brands. The instructions say suitable for up to 10 radiators but I have 12 so thinking that it might be under strength I placed a nail on the magnet of the magnaclean and left it for 3 weeks. The nail came out rust free so I am wondering whether this is just trapped air that has been in the system since the install.

Should I play safe and add a brand name?
Can I safely mix brands?
Can I overdose the rads on inhibitor?

 

[Fluffster]

Brand names down to you but the current one is apparently doing the job
Yes you can mix brands as very few of us ever know what is in a system before
Overdose I would say no you cannot.

Have you tried adding an automatic air vent on the highest point of your pipework?

Since the boiler was replaced 8 months ago with fresh oxygenated water it has to release somewhere.

Pete

 

[Ltnman]

Thanks for that. This is the first time I have read about fresh oxygenated water.

 

[bengasman]

is there any pressure variation in the system?

 

[Ltnman]

How would I tell that?

My old 19 year old system never needed bleeding and apart from bleeding 3 rads over this winter I can't fault the system.

As a side note when I bled the latest rad I did get a whiff of a strange pong.

 

[HARALIAN]

RADIATOR SNIFFER ALERT!!!!!!!!!!!!!!!!!!!!!!!!! You've prob got a tiny weep somewhere ont system as the old one was low pressure no doubt ... Add internal leak sealer just in case

 

[Fluffster]

No !! leak sealer is like porridge in your heat exchanger etc I would certainly not recommend using it esp on a newish boiler.

Have a look at all the rad tails for any sign of leaks.

Pete

 

[Ltnman]

The pressure stays steady apart from when I bleed a rad so I don't think I have a leak.

 

[Ltnman]

Well a year has past since my last post. From last January to when the heating was switched off in May 2009 I carried on bleeding 3 radiators. Today I noticed one of the radiators was almost cold and had to give it a major bleed, which was the first time I have done it this season.

Apart from the bleeding everything seems to be OK. No issues with pressure, no topping up, no leaks that I can see. So what is causing air to get into my system?