How can I fix my Vakera boiler?

I have a Vakers High Efficiency Combi Boiler, compact 29. The lights go through their sequence and stop on the red warning light. I had a pre payment gas meter put in two days ago, I was sent a new gas card to put in the meter which I did this morning. The gas meter turned itself off. I put the card back in to the meter and it turned back on. The boiler has not worked since. I have not had a problem with it before. could the meter turning off coursed this problem and how do I get my boiler to work again please. I have topped the system pressure up to 1.5 BAR.