7 flashes Primary or secondary limit open

What the control is telling you

A high limit is open, or the control is in Watchguard because a limit stayed open longer than 3 minutes. Gas is off and the blower runs.

Applies to: EL195UHNE furnaces with ignition control 103217-03 or 107163-01 (red LED)

Likely causes

• Dirty filter or restricted return/supply
• Blower on too low a heat speed
• External static too high
• Over-firing (manifold pressure high)
• Failed blower motor
• Failed limit switch

Test and repair steps

1. Replace or clean the filter; check that registers and returns are open.
2. Measure external static heating speed must not exceed 0.5 in. w.c.
3. Measure temperature rise (supply minus return) and set the HEAT speed tap so the rise is within the rating plate range (040: 30-60, 060: 35-65, 080: 40-70, 100: 45-75 F).
4. Clock the gas meter (Table 17) and check manifold pressure; correct over-firing.
5. Check the blower motor runs on heat speed (24 VAC on the HEAT tap).
6. If the limit does not reset within 3 minutes the control waits 60 minutes; cycle power or thermostat to retry after the repair.

Settings for these units

• Filter sizes (filter rack kits) · Lennox EL195UHNE