HTP · Boiler

FLU High flue pressure

High severity Elite EL

What the control is telling you

Flue pressure switch shows excessive pressure; pump on. Resets automatically when the pressure is gone.

Applies to: EL-80, EL-110, EL-150, EL-220, EL-299, EL-399 (N/LP)

Likely causes

Blocked flue or vent
Flue pressure switch or its wiring faulty

Test and repair steps

Make sure the flue is not blocked
Jumper the switch to test the wiring; if the code clears, replace the switch and wire the new one in before running the boiler
Never leave a jumper in place - a bad switch must be replaced

Models that show this code

12 models in Elite EL

EL-110 LPEL-110 NEL-150 LPEL-150 NEL-220 LPEL-220 NEL-299 LPEL-299 NEL-399 LPEL-399 NEL-80 LPEL-80 N

Other codes on the same units

CASCADE NO FOLLOWER Cascade - no follower
CASCADE NO SENSOR Cascade - no system sensor
DHW Temperature blocking - DHW demand
FL Low water flow
FOU Outdoor sensor fault
GAS VALVE ON / RUN Ignition then run status
LOCKOUT Lockout (display message)
LOU 24 volt supply low

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Source: Elite EL-80 N Installation Manual (LP-293), p. 67, p. 68. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.