"This has been in the central heating system of our house in one of the coldest areas Englands for 13 years and the house is often empty for weeks on the winter. Never had any frost problems even with sustained -20C. If your house is sometimes empty in the winter, get it!"
"Just fitted home made solar hot water panels last summer.
After seeing what "Specialist suppliers" were charging for solar fluid/antifreeze I thought I’d give this a go. After the worst winter for years, no problems. Good stuff. If it works in solar panels I would think it perfect for holiday homes Ect, no need to drain down the heating ,or keep it ticking over."