Versatile Application: Optimized for cooling-only

Whether you are retrofitting an older boiler or installing a new manifold

making it a versatile choice for monitoring low-side system pressures

having a reliable isolation point is non-negotiable for safety

Always verify your unit's data plate or existing part number before installation

Resideo L8148E1265 Relay 321042-401 Versatile Application: Optimized for cooling-onlyThe Resideo L8148E1265 is a professional grade immersion type high limit aquastat relay tailored for residential and light commercial hydronic heating systems. Engineered for vertical mounting, this Tradeline series controller manages both the burner and circulator motors, providing essential high limit protection within an operating temperature range of 180F to 240F. Operating on 120 Vac, the unit features SPST switching action and a fixed