Upon arrival, I had the homeowner turn on the heat and I proceeded to the attic. I observed that the heating came on and it tripped on high limit. I noticed that the blower did not come on, and the homeowner said the thermostat lost power. I verified my power coming in was 120v and the transformer was producing 24v. The control board is only passing 15-18v to the low volt portions of the control board. The control board is under warranty and on order at Carrier - Allen. We will return Monday to repair the system.