The equipment in this month’s troubleshooting problem is a forced-air electric heating system with five resistance-type elements, and in order to ensure that this equipment can operate with maximum efficiency and prevent an electrical system overload on a call for heat, a multiple-step sequencer system employed.
When you arrive in response to the customer’s complaint that the unit “Is just blowing cool air”, you find the indoor temperature to be cool and uncomfortable and the blower motor is operating. An initial check at the return and a supply register shows a lower-than-normal temperature rise. When you check the wiring diagram shown in Figure One and access the electrical system, you proceed with the following electrical checks.