Central Heating Nightmare

[wifflow1]

Hi Everyone,
New to this forum so forgive me if I have placed this article in the wrong place.
I have been attenting a property that has on going problems with air building up in the open central heating system. The system is approx 25 years old. I have de-sludged several times by pumping acid around the system, drained the system completley off several times and got everything flowing as it should but, with in a couple of days the system is full of air again! Yesturday I used a stronger acid solution and found that it ran clear when I drained it off but this morning the customer telephoned me to say that the water from the cold water storage tank is a dark brown and smells of acid!!! Can anyone help with this one? Its driving me nuts. I just cant work out how the acid has managed to get from the heating system into the cold storage tank.

 

[buffy27]

systems are mixing
1 mistake in piping[unlikely unless u made changes]
2 pump over [i ve seen where heating expansion was over cold storage tank or where the over flows from the f&e and cold storage were tied into one another and back filled one another depending on levels they were set up at.
3 coil is cylinder has hole in it{most likely this one}

in relation to the air i would suggest an auto air vent on the flow out of boiler.
also install one at coil in cylinder[this can be closed once commissioning done]

 

[wifflow1]

I am beging to think you are right about hole in coil. I have checked the expansion pipe and it does return over the central heating header tank so no problem there. But please tell me why would the system keep on getting air in it over night. Oviously, the acid has found a problem with the coil but I know that after I have replaced the cylinder I am still going to have the same problem with this air build up! Nightmare.

 

[buffy27]

I am beging to think you are right about hole in coil. I have checked the expansion pipe and it does return over the central heating header tank so no problem there. But please tell me why would the system keep on getting air in it over night. Oviously, the acid has found a problem with the coil but I know that after I have replaced the cylinder I am still going to have the same problem with this air build up! Nightmare.

no not a nightmare.it worked before it will work again. be positive.
sort the cylinder first,this may be drawing air in.open vented can be a funny system depending on how its piped.the only thing really upsets them is air,air,and air.

 

[wifflow1]

Cheers Buffy, I will get it sorted. Going to try and talk them into a combi!!