central heating drainage

Today I drained my CH/HW. This is a standard vented, pumped S plan with two electric valves, and I'm in UK. I was lucky enough to have a drain valve underneath ground floor, relatively accessible, see pics: However, upon refilling the system, I found out that that valve will rotate...

Hi, having my central heating replaced due to a new extension and the guys installed a drain valve for the central heating outside the house. They basically drilled a hole into the wall and the valve is outside now. Convenient I guess but am worried it may freeze during the winter months. Is...