russ in ar

The smell is the glycol as opposed to dust. How do I know when one just dies? Is the a test I can do?

I have an Intertherm EBH 300 that has the smell of a leak. Do they make a 2'er anymore or do I need to get a 3' replacement? Do I need a new thermostat with the new unit? Also I have an EBH 1350 that stopped putting out heat. I turned it off and took of the covers, everthing looking fine, replaced the covers. Works fine now. Do I have an impending problem in my future? Help anyone? Thanks