Furnace Sequencer vs. Element: Which One Is Failing?
When an electric furnace puts out weak heat, two parts are the usual suspects: a failed heating element or a bad sequencer. They look similar from the vents but are different fixes. Here’s how to tell them apart.
What each part does
- Heating element: the resistance coil that actually produces heat.
- Sequencer: a heat-activated switch that turns the elements on and off in stages, so they don’t all hit the circuit at once.
Symptoms they share
Both can cause weak heat, since either one can leave an element cold. That overlap is why people misdiagnose them.
How to tell which it is
With power off and locked out:
- Test the element with a multimeter for continuity. No continuity = the element is dead.
- If the element tests good but stays cold in operation, the sequencer feeding it likely isn’t closing — it’s not sending power to a healthy element.
- Multiple stages dead at once more often points to a sequencer or control issue than several elements failing together.
The quick logic
- Element good + still cold → sequencer (or wiring/control).
- Element open (no continuity) → replace the element.
Need a replacement element?
If you’ve confirmed a dead element, send us the make and model and we’ll match it — shipped across Canada.
Related guides
- Electric Furnace Not Heating? A Troubleshooting Checklist
- How to Tell If Your Furnace Element Is Dying
Related products
- Furnace Elements
- Lennox Furnace Replacement Elements
- Trane Replacement Heating Elements
- Goodman Replacement Heating Elements
- Rheem Replacement Heating Elements
Need a replacement element? We ship across Canada and build custom elements for hard-to-find equipment.