buderus logamatic r2107

I have a buderus g115 with a logamatic 2107,taco sr506 relay,outdoor reset,3 radiant zones,1 baseboard zone and indirect dhw. All zones have taco 007ifc's.No heat this a.m.-logamatic read"err".Pressed (riello)burner reset,and while the burner fired and ran well(just cleaned and serviced) the heating circulators that had been calling all shut off in about one second.The dhw circ,controlled thru the logamatic not the sr506,kept running.Had to work so I put the boiler on manual and the pumps all ran,incl. dhw.Came home 10 hours later and the problem now is that the dhw circ never shut off and now I have 160 degree dhw!Next I turned the logamatic back to automatic operation and the dhw circ shutoff.Turned up the stats,circs came on,boiler water temp dropped below setpoint and failed to fire.Then I turned the logamatic back to manual control:burner fired,heating circs ran and dhw pump started back up even though the temp was still around 160.Any help on this would be greatly appreciated.(P.S. no youngsters in the house to get scalded by dhw and at 20* out we need the heat on) Thanks to all.