HomeBrandsLennoxHVAC Systems (AC, Furnaces & Heat Pumps)242
L
242
Moderate
Lennox · HVAC Systems (AC, Furnaces & Heat Pumps)
High Temperature Rise
Quick Answer
Error code 242 on your Lennox HVAC Systems (AC, Furnaces & Heat Pumps) means: High Temperature Rise. This is usually fixable — see the step-by-step guide below.
Likely Causes
  1. Dirty or clogged air filter severely restricting airflow
  2. Blower motor speed set too low for heating mode
  3. Undersized ductwork for the furnace capacity
  4. Blocked or closed supply and return registers
  5. Dirty blower wheel reducing air volume
How to Fix It
1
Check and replace the air filter immediately
2
Measure supply and return air temperatures to confirm high temperature rise
3
Open all supply and return registers throughout the home
4
Inspect the blower wheel for dirt buildup and clean if necessary
5
Increase the blower speed setting if the ductwork can support additional airflow
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
Blower motor (if undersized)
Blower wheel cleaning solution
Related Error Codes
201202211214221
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