radiators on upstairs but not down??

we had three power spikes yesterday within 2 hours since then our boiler has been playing up we have hot water and the radiators work upstairs but not down unless we press the reset button.
also the -||- code is flashing longer than 15 mins and the temp display on the boiler goes up from anywhere between 50 to over 99
all the lights are on to say it is working but somethings wrong somewhere
it is a worcester bosch 532 model (5 years old)
help!!!