Mcdonnell & Miller RB-122-E 120volt Hot Water Boiler Low Water Cutoff. Features and Benefits For residential and commercial applications Electronic operation Easy to install and wire Red low water indicating LED Green power indicating LED Now with test button Automatic reset No blow down required 20,000 ohms probe sensitivity Maximum ambient temperature 120°F (49°C) Maximum water temperature 250°F (121°C) Maximum water pressure 160 psi (11.2 kg/cm2) ...