Help with Buderus 234X Logamatic errors out every 2-6 hours

ABK

HELP, our Buderus went through last winter wonderfully iNSTALLED  July 2009.  1 month ago the system shut down and we had to reset (no heat).  2 weeks later it happened again increaining in frequency to every 12 hours and now it happens every 2-6 hours.  It reads heating error and we have to reset it.  It happens on manual or automatic control.  We have 7 zones, one is the hot water.  set at 130 on automatic and 140 ON MANUAL.