Hi all. Just bought a second hand spaform 273. Got powered up and filled with water. When powered up it primed all pumps fine but displays ICE mode. Now when I read the spaform manual this says that all pumps run when in ice mode to prevent freezing. This is great but the heater is not activated. How can I get the tub to start warming up please? At this rate it looks like I’ll haventp wait until the ambient water temp gets to 7 degrees which could be a while. Many thanks