This is the air pressure monitoring fitting which is mounted inside of the hopper on many Harman pellet stoves, inserts, and furnaces manufactured at various periods prior to 2008. All Harman products made after 2009 do not use this fitting. When the glue on this fitting fails, the pressure switch will fail to close and the unit will not feed.
To see if you have this fitting, verify that your stove was manufactured prior to 2009 and that the pressure hose from your switch travels upward and connects at the hopper. Alternatively, open your hopper and clear out the pellets, if your unit has this part, it will be visible inside the hopper.
Stove models with a pressure hose connecting into the air intake plenum do not use this fitting.
This fitting can be found on the following models:
- P38+
- P43
- P61/61A
- XXV
- Advance
- Accentra-Cast
- Accentra Insert
- PF100 Furnace
- HF60