Call to tell them problem with ducted heater pilot flame not stay on and suggest to change theomecouple. They sent a guy and just looked at the machine and immediately tell me the machine is too old and they do not make gas control and need to replace a whole machine and quote $5.5k. This work began a quote job with their charged call out fee. I got a guy from airtask the following day and changed theomecouple and it works.

You need to try your luck by calling them as you don't know who they will send to. I am disappointed on the result.