Hi All 
10 Years ago, I put standard car Ethylene Glycol(includes corrosion inhibitor)anti-freeze in my gravity fed central heating feeder tank to a concentration of 15%. I did this after power failures and very cold weather the year before resulted in burst pipes in CH systems. The system worked far better than before as the fluid (as in a car cooling system) is designed to take away heat from the engine/boiler as efficiently as possible, but the liquid is also easier/faster to heat.
The anti-freeze also helps keep in solution all the contaminants that would otherwise end up as sludge. After some months I inspected the header tank and removed a solid film of sludge which I think would have been oxidised contaminants since the water here was exposed to air. I ran this boiler and system for 10 years with the addition of the anti-freeze also improving efficiency and reducing fuel costs.
Now I have converted to a combi pressurised system and I'm mulling over whether to add car anti-freeze again. Currently I have Protex in the system for corrosion inhibitor, but this does not protect against freezing or allow water to be heated easily and to cool easily. I'm wondering if there would be any issues with using in a pressurised system?
Thoughts anyone?
I can't stress enough the improvement this made in my old system.
Cheers All
10 Years ago, I put standard car Ethylene Glycol(includes corrosion inhibitor)anti-freeze in my gravity fed central heating feeder tank to a concentration of 15%. I did this after power failures and very cold weather the year before resulted in burst pipes in CH systems. The system worked far better than before as the fluid (as in a car cooling system) is designed to take away heat from the engine/boiler as efficiently as possible, but the liquid is also easier/faster to heat.
The anti-freeze also helps keep in solution all the contaminants that would otherwise end up as sludge. After some months I inspected the header tank and removed a solid film of sludge which I think would have been oxidised contaminants since the water here was exposed to air. I ran this boiler and system for 10 years with the addition of the anti-freeze also improving efficiency and reducing fuel costs.
Now I have converted to a combi pressurised system and I'm mulling over whether to add car anti-freeze again. Currently I have Protex in the system for corrosion inhibitor, but this does not protect against freezing or allow water to be heated easily and to cool easily. I'm wondering if there would be any issues with using in a pressurised system?
Thoughts anyone?
I can't stress enough the improvement this made in my old system.
Cheers All
