s and boiler stand?

Our solar collectors and boiler can stand temperatures to -35°C when properly installed. The closed circuit runs on glycol antifreeze mixed in various proportions with distilled water to better answer to local changes in winter temperatures whereas the boiler has an internal electric resistance that keeps the water warm enough not to freeze. If the boiler is not used for long periods (winter home used only a few weeks a year), it is always better to either keep the electric circuit on or to turn it off and drain the boiler to avoid serious damage.