As Tambo said, Jenna............. big tank upstairs is hot water....... 60 degrees. That's ok. It doesn't affect the heating.
The one in the lounge should click as you turn it up. It's then that the heating should come on.
It sounds as though you have a gravity system (tanks in the roof) rather than a combi. See if you can find the circulating pump (possibly near boiler, or next to "big tank upstairs")
Over the summer, this may have stuck. One or two discreet taps with a mallet might wake it up. If it's not that, and it's running ok, then you should hear it humming.