RTU #2 is off and awaits a replacement heat exchanger. Darlene to check on the order status tomorrow. RTU #3, which also serves the front lobby was not operating because of a limit fault. I looked and found the blower belt shredded and off and I guess it pulled a lead off the limit switch when it snapped. I replaced the belt and put the wire back on the limit switch. I believe the belt was just a bad belt. I couldn’t see any burrs on the pulleys or misalignment opportunities. RTU #3 fired up and is operating normal.