Heil Quaker ICP 1056789 Heat Sequencer

The Heil Quaker ICP 1056789 Heat Sequencer is a critical DPST (Double Pole Single Throw) control designed for staged activation of heating elements and blower motors in electric furnaces and air handlers. Engineered for 24V coil applications, this OEM replacement part prevents high-amperage inrush by sequencing resistive loads, protecting the circuit from residential breaker trips during the initial call for heat. With a timing specification of 1 to 20 seconds on and 40 to 110 seconds off, this heat sequencer relay ensures the heating elements reach operational temperature before the blower engages, eliminating cold drafts and maintaining consistent discharge air temperatures.

For technicians servicing International Comfort Products (ICP), Heil, or Tempstar units, this sequencer provides exact fit compatibility for models including the AMMK and AEB series. The robust bimetal construction is built to withstand the thermal stress of frequent cycling, ensuring reliable contact closure across all 3 poles. Integrating this furnace sequencer into your maintenance routine mitigates the risk of contact welding or heating element failure caused by improper timing or simultaneous load spikes.

• Staged Element Activation: Eliminates electrical surges by timing the engagement of heat strips in sequence.
• Precise Fan Delay: Correct 1-20 second ON delay ensures the heat exchanger is primed before air distribution begins.
• High-Amp Capacity: Designed to handle heavy resistive loads common in electric furnace parts without premature contact pitting.
• Universal ICP Compatibility: Direct drop-in replacement for part numbers 1056789, 713470, 704845, and 703605.

How do I diagnose a failing 1056789 heat sequencer?
Common symptoms include heating elements remaining energized after the thermostat is satisfied (stuck closed) or the blower fan failing to kick on despite the elements glowing (stuck open circuit). Use a multimeter to check for 24V at the heater coil and verify continuity across the load terminals after the specified delay.

Does this sequencer control both the fan and the heating elements?
Yes, this multi-pole sequencer is designed to stage the heating elements while simultaneously managing the blower motor timing to ensure heat is present before the fan starts circulating air.

What causes these sequencers to fail prematurely?
Failure is typically caused by bimetal fatigue from excessive cycling or "chatter" if the 24V control voltage is unstable. Always check for tight electrical connections to prevent localized overheating at the terminals.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.