Be aware that the Clarke machines (one of which I have) as with all others with ceramic pistons need some serious protection from the cold. I thought i'd done a good job insulating my machine last year, but the pump had still frozen and cracked a piston.
Getting a replacement piston for my Clarke machine was laborious. They have been on back order for 3 years, but were due in in the next fortnight. They never arrived and eventually they had to strip down an obsolete machine to sell me the pistons. Lesson learned.