HVACopediaRheem · Furnace
23 HALC limit open (HALC LIMIT OPEN)
What the control is telling you
Heat Assisted Limit Control open. HALC is only on downflow/horizontal models; when it opens it often means the main blower stopped turning unexpectedly. Thermostat also shows Call For Service / CHECK FURNACE to the homeowner.
Applies to: RGPE/RGLE 2-stage 80+
Likely causes
- Blower stopped or failed (60/61/68)
- Airflow restriction
- Loose HALC wiring
Test and repair steps
- Check whether the ECM blower is running; troubleshoot blower faults first.
- Check for airflow restrictions dirty filter, dirty blower wheel, closed dampers or registers.
- Check wiring between IFC and the HALC.
- Check temperature rise is within range.
- Check the HALC resets once the blower runs; replace if open at normal temperature.
Settings for these units
- Filter sizes as shipped, upflow (Table 19) · RGPE/RGLE
- Reduced clearance to combustibles (Fig. 3 and 4) · RGPE/RGLE
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Source: RGPE/RGLE: Table 16 p.49 / Table 20; user menus p.52. Summarized in our own words; check the original manual for your model.
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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.