Ignition Transformer Replacements

Finding suitable alternatives for obsolete ignition units.

Verification Required

Replacing ignition transformers involves more than just voltage matching. Electromagnetic Interference (EMI) from new solid-state igniters can disrupt flame signals. Always verify ignition success rates under various conditions.

Replacement List

BrandDiscontinued ModelEnd of LifeOfficial ReplacementKey DifferencesInterchange?Action / Advice
HoneywellQ652 (Solid State)2022-12-30ET401 / ET402Official replacement family. ET401 is 120V. Verify electrode gap and EMI interference.ConditionalSelect ET401/402 based on primary voltage. Test for flame detector interference.
SiemensZM 20/12DiscontinuedEquivalent (Check Specs)No official direct replacement. Match Primary V, Secondary kV/mA, Duty Cycle, Insulation.NoPrioritize Burner OEM spares. Perform ignition test (cold/hot/worst-case).

Priority Procurement & Maintenance Advice

  • Honeywell Q652 → ET401/ET402: Use the official replacement family. Ensure voltage matches (120V vs 230V).
  • General: If no official replacement exists (e.g., Siemens ZM), match specifications carefully: Voltage, Current, Duty Cycle, and Mounting.
  • Testing: Schedule a re-commissioning window to test ignition reliability (cold start, hot restart).