Can I use a 30-amp contactor instead of this 40-amp model

The Modine 5H0749760007 Limit Switch is a critical OEM replacement part designed for high-limit temperature protection in Modine unit heaters and Hot Dawg series garage heaters

this is a natural gas orifice with a

the unit maintains an open circuit mV range of 25–35 mV

though the specific orifice size in your manifold determines the gas type compatibility

York S1-025-12804-900 Fuse Can I use a 30-ampThe York S1 025 12804 900 is an essential OEM safety component designed to provide high voltage circuit protection in commercial and residential HVAC systems. Rated for 20A 600V, this fuse prevents damage to critical components like control boards, fan motors, and compressors by interrupting electrical flow during overloads or short circuits. This specific York replacement fuse is engineered for a precise fit in numerous air conditioners and heat