Hello. My name is XXXXX XXXXX I'll do my best to help. Troubleshooting often requires meters and test equipment. Let's get started and see what we can do. Depending on how much heat you need. The 15KW kit is available here.
The heat kit for these units is ECB29EH. Then after those numbers will follow 9CB for 9KW, 12.5CB for 12.5KW or 15CB for 15 KW
Thanks for response. The air handler is wired with a 40 Amp circuit breaker which would equate to 8800 watts @ 220 volts. Allowing for the power the blower takes what size heater should I get?