Accidentally turned off immersion heater - now no CH or HW!

[ImmersionHelp]

Hi,

I have a boiler in my kitchen and a water tank in the airing cupboard. My friend turned off the immersion heater via a switch on my wall 4 days ago, I have only just noticed this now as I have no central heating or hot water. I turned the heater back on yesterday and left the tank for an hour or two to heat up - I then put on the central heating but still the radiators remain cold.

Does anybody have any ideas as to what the issue could be?

I have an Optimax HE 25s and when I turn the CH or HW on, no flame icon appears on the display. I'm not sure if the icon should or shouldn't display, but it makes me wonder if the boiler isn't lit. I have no idea how to understand the Ignition instructions on the instructions if this is the issue.

Hope someone can help - the weathers turning cold here!
Thanks

EDIT: The immersion heater switch is on and there are no fuse box issues.

 

[lame plumber]

get a plumber to come and show you how it all works switch wise and check the immersion is working and look at the boiler and give it a service. ps immersion heaters dont run your central heating