I am working on a electric furnace and I thought since the transformer was only putting out 2.8Volts that it must be bad. I went and got another one and wired it in and it reads the same. Nothing seems to be open in the system and I can't power up the thermostat to kick on the furnace. Could the relay be bad?

What is the input voltage to the transformer?

I got two legs of 120 volts but only 2.8 is coming out of the transformer

What is the input voltage to the transformer?

I got 240 into the transformer and only 2.8v coming out

Is the 2.8v with the transformer connected to the relay? If so disconnect the relay or whatever is connect to the 24v side of the transformer and check the voltage. If 24v is present, the problem is AFTER the transformer.