HTP · Boiler

FL Low water flow

Menu / mode display Elite EL

What the display is showing

Flow switch shows too little flow; pump on.

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

Good to know

Flow switch problem. Note: this model has no flow switch, so this code is for other HTP products.

What to do

Check that the boiler pump works
Make sure water is flowing valves open, filter screens clear
Check the flow switch and wiring

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 MASTER READY Cascade master ready
CASCADE NO FOLLOWER Cascade - no follower
CASCADE NO SENSOR Cascade - no system sensor
DHW Temperature blocking - DHW demand
FLU High flue pressure
FOU Outdoor sensor fault
GAS VALVE ON / RUN Ignition then run status
LOCKOUT Lockout (display message)

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

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.