Thanks for all your help Robert

The one that wasn't working supplied 24 volts across the heat side on the selector switch and then went to the sequencer. But replacing that transformer has fixed the problem with the heat. The part number that was listed on the side of the old transformer was 6214140. It had a tap for an input volt...

I ordered a 240v 40VA 24volt output transformer part number 025-18452-700 from Aberdeen and what they sent was a 240V 10VA 24volt output transformer part number 3400-3841, will this create a problem if I use it? It did fix the problem I was having with the heater but is this one too small to work ov...

I checked again. That transformer has an input of 248 and no output, but I don't think it really has anything to do with the A/C. I completely disconnected the input to the transformer and the A/C still came on. I'm going to go ahead and order that transformer. Thanks for all your help on this.

when I go across the terminals I read 240

I think I was looking for some type of circuit card or something. I finally figured out that circuit and I'm only getting about 8 volts from that 24 volt transformer. On its label it shows a part number of 6214140 do you all carry one of those or one that'll work?

I still haven't been able to find this sequencer. The only thing I have on this EB17A is 901698 relay box and from there the wiring harness goes to the fan and to the heater elements via a small tranformer. I have taken out the heating elements just to make sure the sequencer wasn't in the vent shaf...

I can check all that but I'm not sure where the sequencer is located. Also, if I want to check the t-stat, since its a two wire unit can't I just short out the wires to see if it kicks on the heater? I went ahead and jumped out the two wires coming from the t-stat and I can hear the relay # 621099 c...

I have an EB17A, which is the one with the 901698 relay box. The fan works fine, the A/C works fine, but when I select heat neither the fan or the heater come on. Any ideas? Maybe a relay box problem or even a sequencer, if this unit even has one.