my fan cycles on with the thermostat but the heater coil only gets 120v instead of 240v so it does not heat. had a power surge and brown out when problem started. think problem is at the heater sequencer and think it moght be the crr9-5 rectifier. anyone have any suggestions? mistake in tag line it is a carrier 50jx042 unit
Where did you take the 110v. reading? Do the coils even warm up at all? Power surge....you sure you didn't bow a fuse link or maybe have a stuck sequencer or realy? You gettin' 220/240 to the heat kit itself?
110 was across heat unit. coils are fine and if sequencer and relay are by passed coils get 220 and heat up. i think the problem is either retifier crr9-5 that controls 24v to sequencer or sequencer itself. not sure how to check sequencer?
Yea, both the relay and the seqencer are normally open and 24v closes them. If your getting 24v to them then they will show continuity after they close...either can have a delay (especially the sequencer) so you may have to wait a minute for the close