7 flashes
Moderate
Rheem · HVAC Systems & Water Heaters
Limit Switch Open
Quick Answer
Error code 7 flashes on your Rheem HVAC Systems & Water Heaters means: Limit Switch Open. This is usually fixable — see the step-by-step guide below.
Likely Causes
How to Fix It
1
Check and replace the air filter immediately
2
Verify all supply and return registers are open throughout the home
3
Measure the temperature rise across the furnace and compare to the nameplate range
4
Check the blower motor and capacitor for proper operation
5
Measure static pressure in the duct system (should not exceed 0.5 in WC)
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Air filter
High-limit switch
Blower motor capacitor
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