Water & anti freeze

[fred1949]

My question is how much anti-freeze should my geothermal furnace have in it. I checked the water myself & it had very little, it didn't float a ball on my tester. My new furnace repaiman said it will be $254 for the flush & $99 for the anti-freeze. Are those fair prices?

Thank you,
Fred

[HayZee518]

You'll have to figure out the capacity of your closed loop system. From what I've read a closed loop system may contain over 400 feet of piping buried 6 foot down or just under the frost line. Acceptable antifreeze solutions are propylene glycol, methyl alcohol and calcium chloride. propylene glycol is the same stuff in a car cooling system. calcium chloride is "snow melting pellets" - not sure about the methyl alcohol - will look into that. The system flush - I guess there are two valves for servicing. Hook up a pump and force clean the insides of the pipe. Depending on the antifreese solution, the contractor will have to dispose of the used stuff so that adds to the cost of flushing. prestone antifreeze - I've seen it at $11 for a gallon of it in auto stores. Methyl alcohol is also called methanol or wood alcohol. It is basically a defatting agent. It is flammable and toxic. There's an MSDS sheet on the stuff.