Went on a call today, customer had replaced Contactor relay said that when he turned his heatpump on it would start chattering . Got to the sight realized that it was the fan relay chattering not the CC. Checked the board 24 Volts in but the voltage coming out was flucuating from 24 too 14 volts not allowing the fan coil to stay interjized I was just wondering has anyone seen this flucuating out of a defrost control board ? Normally the ones I get are either good or bad . Heil CH5024VKB3
Yep, when I recently replaced a defrost board in an ICP 50 series unit the fan relay chattered. Turned out that I had to bring a common directly from the contactor to the board. You may have a bad connection on the common off of the contactor.