When you try to activate the pump, you are pressing the start button twice so the whole dash lights up?
This is the sequence....
1.Insert the key into the dash slot and hit the starter button (but don’t start the engine – e.g. keep your foot off the bake/clutch).
2When the ignition is on, set the heater to the highest temperature and set the fan on low.
3.Hold down the accelerator pedal for 10 seconds then release.
This activates the water pump and it will cycle for about 12 minutes to vent all the trapped air into the coolant reservoir (it sounds like a min washing machine).
Don’t open the reservoir cap or bleed screw during the venting process! (you’ll have start the process again)
In your case do it with the lid off to see if it starts.
4. Once the water pump stops after 12 minutes, open the reservoir cap (it will hiss a little) and add coolant until the measuring stick (ball indicator) is 6 mm above the top of the filler neck.
There is also a fuse 30 or 40a in the compartment in the bonnet, this is for the water pump.
Check to make sure that is OK if the pump won't do its bleed cycle.
Also, you MUST check your thermostats are working.
If they are not working properly you pump not not kick in.
If you pump is not working, the main fan should start on start up, it is a safety feature.
If the fan is kicking in straight away then I would check the fuse.