Re: 22-23 series heater

Posted by JD in KC On 2013/10/27 10:05:33

Howard,

I don't know how helpful this may be but there were changes made between the 22nd and 23rd series fresh-air heater systems. With the 22nd series, to operate the heater, both the left and right air knobs are turned off (full right position). The 23rd series requires that the right air knob be turned fully open (full left position) past the index mark used to direct air to the ventilation grill.

The two (48 & 49) owners manuals on the site describe this better than I do.