If your Trane electric heater did not smell last winter and does now, the most useful diagnostic question is not what is burning — it is what changed. Electric heat does not develop new smells for no reason. Something is different this season: a part aged past its limit, something in the house changed, or an event left damage behind. This page is a change audit: how to trace a new burning smell back to the change that caused it, in your Keystone home.

Start With the Calendar: When Did the Smell Start?

The timing of the first smell eliminates half the suspects. A burning smell on the very first heating cycle of the season, light and dusty, fading within 20 to 60 minutes, is dust burn-off on the elements — the one smell that needs no change behind it, because the change is simply the season turning. Note it and move on.

A smell that starts mid-season, weeks after the heat has been running cleanly, is the audit case. Nothing about the season changed that week — so something else did. The same goes for a smell that is new this year but absent last year. Write down when it started; the technician will ask, and the answer narrows everything.

The Usual Suspects: What Changes Between Winters

Run through the changes that most often sit behind a new burning smell:

  • A new thermostat. A replaced thermostat with wrong cycle-rate or anticipator settings can short-cycle the strips or hold calls too long, concentrating heat and producing smells the old thermostat never caused. If the smell started within weeks of a thermostat swap, say so first.
  • Electrical events. Power outages, panel work, or utility work on the street can leave sequencers and contactors damaged. The failure hides until the first long heating call, so the smell seems disconnected from the event — but the audit connects them.
  • Filter habits. A filter changed religiously last year and neglected this year starves the strip bank of airflow. Elements run hot, the high-limit safety cycles, and dust bakes onto overheated elements again and again. The change is not in the equipment; it is in the maintenance.
  • Renovations and dust. Drywall work, new carpeting, or any project that filled the air with fine dust loads the elements and the filter far beyond a normal season. Post-renovation smells are dust burn-off on an industrial scale — check the filter before anything else.
  • Setback schedule changes. A new work-from-home schedule, a new baby, a houseguest — anything that changed when and how long the heat runs changes which parts get stressed. Longer calls expose weaker parts.
  • One more year of age. Sometimes the change is simply time. A sequencer that was marginal last winter is failed this winter. Wear does not announce itself; the smell is the announcement.

The Change That Matters Most: Electrical Work and Outages

Of all the changes, electrical events deserve their own section because their damage is invisible until it is not. A return-surge when power is restored pits contactor contacts and burns sequencer heaters open. The parts sit quietly for months. Then the first sustained heating call draws full current through the damaged contacts, they overheat, and the vents carry an acrid, electrical smell that dust never produces.

If there was an outage, a panel upgrade, or any electrical work between last winter’s clean heat and this winter’s smell, that is the lead suspect — tell the technician before the visit. It changes what gets tested first and how the findings get documented.

What Hasn’t Changed: The Parts That Were Already Weak

The audit has a second outcome worth naming: sometimes nothing changed except the calendar, and the smell is pure wear reaching its limit. A sequencer’s contacts degrade a little every season; a wire terminal loosens a fraction every heat cycle. Last winter the parts were weak but working. This winter they are weak and failing. The amp-draw test tells this story clearly: a strip drawing current when it should be off, a stage that never engages, uneven draw across the bank.

Wear is not a lesser diagnosis. It is the most common one, and it is the one the maintenance visit is designed to catch — amp draw per strip, sequencer timing, connection inspection, limit-switch verification, all measured before the heating season rather than after the smell.

The Audit the Technician Runs

Bring your change list to the visit — it shortens the diagnosis, and it is the first thing our Keystone technicians ask about. The technician starts with the timeline you provide, then runs the electrical proof: amp-draw readings on every strip through a full staging sequence, contactor inspection for pitting or welding, terminal inspection for the discoloration of arcing, limit-switch verification. The readings either confirm the suspected change or rule it out — either way, the smell gets a cause, not a guess.

Most findings resolve in a single visit: the failed part replaced, every connection in the circuit inspected and re-terminated, the staging test run clean. Our vans carry the sequencers, contactors, and strip-bank components these repairs need most, with same-day dispatch across Keystone. Genuine Trane parts restore the staging behavior exactly as engineered, and warranty-safe service protects the coverage you already carry.

The heat smelled fine last winter. Why now?

Because something changed — a part aged past its limit, the thermostat was replaced, there was an outage or electrical work, filter habits slipped, or renovations loaded the system with dust. The change audit above walks through the suspects in order.

We got a new thermostat this fall. Could that be it?

Yes, and it is one of the first things to check. Wrong cycle-rate settings can short-cycle the strips or hold heat calls too long, both of which overheat elements and produce smells. Mention the thermostat swap when you call — it changes the diagnostic starting point.

There was a power outage last month. Is the smell related?

Very possibly. Return-surges damage sequencers and contactors, and the damage hides until the first long heating call. An acrid, electrical smell that started after an outage points at surge-damaged controls rather than dust.

We remodeled over the summer and now the heat smells. What do I do?

Check the filter first — renovation dust loads filters and elements far beyond normal. Replace the filter, run one heating cycle, and see if the smell fades. If it persists past the first cycle or smells acrid rather than dusty, schedule service.

Nothing changed that I know of. Now what?

Then the change is wear, and the amp-draw test finds it: a strip drawing current when it should be off, a dead stage, uneven draw across the bank. “Nothing changed” is itself useful information — it points the technician straight at component wear.

How long does the diagnostic visit take?

The audit plus the full electrical test — amp draw per strip, contactor and terminal inspection, staging verification — typically fits in a single visit of one to two hours, with most repairs completed the same trip.