Engineered as the direct replacement for the legacy F59H-6 model

They are interchangeable within the Lennox parts catalog for the same furnace models

This adapter provides a reliable mechanical fit that prevents accidental disconnects during high-vibration burner cycles

preventing over-firing or incomplete combustion in propane gas applications

burner control

Hydrotherm 02-1554 Gas Valve 30067439-890 Engineered as the direct replacementThe Hydrotherm 02 1554 Gas Valve is a critical combustion control component engineered for high performance natural gas hydronic systems. Designed specifically for Hydrotherm MR and VGA boilers, this valve ensures precise fuel regulation and consistent manifold pressure. Operating on a standard 24V AC circuit, it maintains a factory calibrated 3. 5" WC (Water Column) output, which is essential for stable flame characteristics and efficient heat