Corrosion Inhibitor - How can you tell it is working ?

[self builder 123]

Hi

We have new CH system. It is a combination of underfloor heating, radiators and heated towel rails.

We needed to heat the house before the towel rails and radiators were fitted so we looped the pipe work for the radiators and heated towel rails and powered up the system.

At the same time we added Fernox Restorer to flush the existing pipe work and then added 8L of Fernox MB1 to avoid against any corrosion in the underfloor heating manifolds and / or the boiler.

Perhaps a bit of overkill at the time, but it was some time before the 2 x radiators and 2 x heated towel rails were subsequently fitted.

Before the radiators and towel rails were fitted we flushed these outside with a garden hose and then fitted them.

When the system was drained to fit the rads and towel rails the inhibited water remained in the underfloor heating pipe work. The majority of the system water is in the underfloor heating pipework.

In total there is 205L of water in the central heating system including rads and towel rails.

Once the rads and towel rails were fitted we topped up the water, but did not add any more Fernox MB1 at the time.

The other day we had to remove one of the towel rails and found that the water inside was a dark brown clour. It had a slight chemical smell and a slight amount of soapy bubble froth.

So after all this my questions ?

1. Should reclean the system with Fernox Restorer as the towel rails and rads were added after the initial clean ?

2. Could we simply add more Fernox MB1 ?

3. I take it that the water in a fully inhibited system should be almost clear ?

Cheers in advance.

 

[bengasman]

Not that it is important, but how on earth do you know there is 205 litres of water in the system?

1. In short, the system can be clean enough, but never too clean. in case of doubt, drain, fill and add cleaner, run for a day and check. If noticeable dirt present, leave for a few more days.
2. Drain as many time as it takes to get water really clean, if you can not drain the system completely, this may be many times. Very boring.
3. Fill and add sufficient inhibitor. Sufficient is: “I think this will do” plus one bottle.

No reason not to diy this as it is more a matter of patience than of skill. Balancing needed afterwards which is a matter of skill and tools, never seen anyone doing it right on HE system who was not a pro. Have seen lots of pro’s botching it.

Colour of the water is not overly important though in theory should be almost clear. If there is a low amount of microscopic sized dirt particles in the system, it will look darker than 10 times more dirt of bigger size.
the bigger particles are the ones that cuase problems