PH 8 in heating system

[flyboy]

I have just had a gas heating system installed. (see also thread on Power Flushing). Following the 'flush' the installer said something about chemicals in the system. I decided to get some PH paper from ebay and test the water. How accurate are these papers - its hard to tell if the water is pH 8 or 9? How do you get an accurate measurement? I think it would be much better if the pH was neutral ... how much flushing would be needed to do this?

Would this pH8 be due to neutraliser?

I remember reading once (must be 30 years ago) that if you used acid in cleaning out a system you needed to flush 5 times to remove it.

 

[newbie1]

depending on flush chemical used the acidic ones require you to add neutrilsing crystals or liquid and then flush that round and then out