Amana AMVM970803BN Error Code EE3: Primary Limit Circuit Open

What Does Code EE3 Mean?

Code EE3 means the primary (high) limit circuit opened because the heat exchanger got too hot. The furnace shuts off the burners for safety but keeps the circulator blower running to cool things down, so you may feel cool air blowing while no heat is being produced.

Overheating on this furnace is almost always an airflow problem: not enough conditioned air is passing over the heat exchanger to carry heat away. The leading cause is a dirty, clogged air filter, followed by blocked registers or restrictive ductwork, an improper blower speed, or a failing blower motor.

EE3 is closely related to the airflow codes Eb3 and Eb9, which warn about restriction before it becomes an overheating shutdown. Clearing a dirty filter early often prevents EE3 entirely. Persistent EE3 with a clean filter points to ductwork or the blower, which are professional issues.

What You'll Notice

• The blower keeps running but the air is cool and no heat is produced, with EE3 displayed
• The furnace short-cycles: burners light, then shut off from overheating
• The air filter is visibly dirty or clogged
• Some registers or the return grille are closed or blocked

Common Causes

How This Is Diagnosed

Diagnosis starts with airflow: the filter is checked first, then registers and ductwork for blockage. If a clogged filter or closed registers were starving airflow, clearing them stops the overheating and EE3 clears.

If the filter is clean and airflow paths are open but EE3 persists, a technician checks the circulator blower speed and performance and the high-limit circuit wiring, since an improper blower speed, a failing motor, or a loose connection can also cause it.

How to Fix It: Restore Airflow to Stop Overheating

What You'll Need

• Replacement air filter (correct size) 🛒 Find at FiltersFast · 🛒 Find at Amazon
• Flashlight

Steps

1. Turn off power at the breaker or furnace switch and shut off the gas supply before servicing Set the furnace service switch to OFF (or trip the breaker) and turn the manual gas valve perpendicular to the pipe. If you smell gas, leave immediately and call your gas company.
2. Check and replace the air filter Slide out the filter and hold it up to a light. If light does not pass through, replace it with the same size printed on the frame. A clogged filter is by far the most common cause of EE3 overheating.
3. Open all supply registers and the return grille Walk the house and confirm every register is fully open and unobstructed, and that the return-air grille is clear. Too many closed rooms starves the furnace of the airflow it needs to shed heat.
4. Look for obvious duct restriction Check for a crushed flex duct or a closed damper you can reach, and make sure nothing blocks the blower inlet. Do not disassemble ductwork.
5. Restore power and run a full cycle Turn the gas back on, restore power, and call for heat. With airflow restored, the furnace should complete a heating cycle without overheating and without EE3 returning.

When to Call a Professional

Contact a licensed HVAC technician if:

• EE3 persists after the filter is replaced and all registers are open
• The furnace keeps short-cycling on the limit with clean airflow
• You suspect the blower is running at the wrong speed or is failing
• You suspect restrictive or undersized ductwork

✓ Verified against manufacturer service manual — March 2026