Stockpile Express offers a selection of heating system relays and related accessory parts. Essential to any properly functioning heating system, a relay triggers your boiler or furnace to release heat based on a signal from the thermostat. We offer relays as well as controls, switches, and timers to ensure your heating system works as intended. Browse high-quality heating parts from Lochinvar, Burnham, Weil-McLain, and other top brands at Stockpile Express.