Heating not working. Worcester greenstar 24i junior?

The hot water still works but the heating doesn't come on. Wireless thermostat has been reset and looks like it is 'talking' to the boiler but it, the boiler, doesn't 'kick in' when it needs to. The boiler was serviced a couple of months ago. We tried the fault finder from another thread wth the same question, and it made the heating come on. The pressure went to the highest part on the green line (but eventually came down again). The blue light flashed fast 5 times, then went off, then flashed 5 times then off (and so on) for approx 10 minutes. The boiler still wont come on when asked by the thermometer, but seems to work when going through the fault finding.

Any help greatly appreciated!