If your electric furnace won’t turn on, you’re likely left with a cold house and some serious questions. Electric furnaces are generally reliable, but when something goes wrong — whether it’s no heat, no blower, or nothing at all — it’s important to understand the system and diagnose the problem safely.

This guide covers the most common causes for an electric furnace not turning on, model examples, key components, and when it’s best to call a professional in NJ.

Common Electric Furnace Models

Electric furnaces use high-resistance heating elements (like large coils) to generate heat, then circulate warm air via a blower motor and ductwork.

Common residential models:

Goodman MBR series (MBR1200AA-1, etc.)
Nordyne E3 series
Rheem RHSL/RBHP air handlers with electric heat kits
Trane TEM6 or TEM4 models with strip heat add-ons

These units typically require a dedicated 240V power supply and include internal safety switches, sequencers or relays, and multiple heating elements.

1. No Power to the Furnace

Check the following:

Main breaker panel — Electric furnaces often require 30–60A double-pole breakers. Reset if tripped.
Service disconnect box — Should be mounted near the unit.
Internal breaker/fuse — Some models include an internal circuit breaker or cartridge fuse.

If no power is present at the blower or control board, check the disconnect and panel before opening the furnace cabinet.

2. Blown Limit Switch or Thermal Cutoff

If the furnace overheats, it will trip a high-limit switch or thermal cutoff.

Usually resets manually or automatically once cooled
Causes: Dirty filters, blocked returns, failed blower motor
Most models have multiple limit switches — test continuity with power off

3. Bad Sequencer or Control Relay

Electric furnaces use sequencers or relays to stage heating elements and the blower motor. If these components fail:

The blower may run but no heat is produced
The unit may hum but not energize the elements
Nothing may happen at all

You’ll need to test voltage across the sequencer contacts — usually 24V control side and 240V line side.

4. Thermostat Problems

Make sure it’s set to heat, not fan or cool
Raise the setpoint 2–5°F above room temp
Check the R to W signal voltage at the air handler — should be 24V
Low batteries, disconnected common wire (C), or bad stat can cause no heat calls

5. Bad Heating Element or Open Circuit

If the unit powers on but produces no heat:

Heating coils may be broken or burned through
Check continuity across heating element terminals
Look for burned wires or cracked insulators near the elements

Heating elements must be replaced with model-matched parts — voltage, length, and shape must align with the OEM.

6. Blower Motor Failure

No airflow = no heat circulation.

Motor may be seized or bad capacitor
Check for power at motor terminals
If motor hums but doesn’t turn, suspect capacitor

Many electric furnaces use PSC motors with a 5–10 µF run capacitor. Match both microfarad and voltage rating.

Should You DIY or Call a Pro?

DIY Risks:

240V electrical components are dangerous and potentially fatal to work on
Misdiagnosis can cause overheating, element burnout, or fire
Replacing parts with incorrect ratings can void warranties and increase risk

When to Call a Pro:

You don’t have a multimeter or wiring experience
You suspect a bad sequencer, motor, or element
You’re unsure about breaker sizing or wiring

In NJ, HVAC pros can get same-day access to parts from distributors like:

Johnstone Supply
Ferguson HVAC
Sid Harvey’s
United Refrigeration

If your electric furnace won’t turn on, it’s often due to power issues, thermostat failure, limit switch trips, or a blown sequencer or heating element. Always check your power supply and thermostat first — and if you’re not 100% sure, play it safe and call a licensed HVAC technician.