Have tried pumping up water from downstairs, but no luck, any ideas?

Hi Sineadfl...

Is the weather freezing in your area? If so, you probably have frozen water lines in the outside wall. Here, you would heat the pipes using a hair dryer or paint stripper gun and begin to thaw them out. Be sure to open all faucets upstairs so steam can escape and you can know when the pipes have thawed, OK?

If you do not suspect frozen pipes and both hot and cold water is down to all fixtures then I might suspect that someone has turned off a common set of shutoffs going upstairs by mistake as there is not usually a common reason for both hot and cold water pipes to stop flowing... unless frozen, as mentioned.

You could also check the aerators, the shower head and the toilet fill valve to see if something got into the plumbing and clogged the valves

That should get you started. Any questions just let me know, OK?

Mark