EWC-ST-2C controller

[HotAir_NYH]

Hi, there,
I have a 2 Zone system with an EWC-ST-2C controller. The system was installed in my home in the late 1990s. Until now it has no problem. Recently, my gas hot air blower is not working properly. After the automatic start, sometimes there is hot air and sometimes not. Sometimes it turns to cool air after working about half an hour. I wonder if it is a controller or other problem, I am looking for information about troubleshooting? Thanks!

[Paul Z.]

Give me a call 1800 446 3110 X490.