The "A" prefix indicates a 1/2 inch top width

When diagnosing delayed ignition or fluctuating heat output in SRP heaters

including models 990

it offers a wide pressure range from 200 psi to 610 psi

Designed to withstand the thermal stresses of high-duty cycles

Resideo TH401 Thermostat 326058-757 The "A" prefix indicates aThe Resideo TH401 electric heat thermostat is a specialized non programmable line voltage thermostat designed for precision control of baseboard heaters, convectors, and fan forced heaters. This SPST switching unit operates across 120V, 208V, and 240V configurations, handling a maximum load of 2500W at 240V. Built with a triac switch, the TH401 eliminates the clicking noise associated with mechanical relays, ensuring 100% silent operation in