HVACopediaGlow Brand · Boiler · Heating
Central heat call and post purge
What happens, in order
- Demand comes from thermostat or end switch on terminals 9 and 10 (mode 0), or from the outdoor sensor (mode 2), per CH mode parameter 2.001
- Outdoor reset modes (1, 2) calculate the setpoint between design supply 2.019 and baseline supply 2.021 using outdoor temperature
- Mode 2 runs a permanent demand while outdoor temperature is below warm weather shutdown (2.025)
- Boiler fires and modulates to reach the CH setpoint (2.003)
- When demand ends the burner stops and the fan post purges
- After post purge the primary and CH pumps keep running for the CH post circulation period (2.005)
Timings and thresholds
| Item | Value |
|---|---|
| CH setpoint | parameter 2.003 |
| CH post circulation | parameter 2.005 |
| Warm weather shutdown | parameter 2.025, default 72 F |
Applies to: B85, B120, B160
Models
B85B120B160
More Glow Brand boiler sequences
- Power-up and de-air · Startup
- Ignition and retry · Ignition
- Indirect tank call and priority · Domestic hot water
- Anti-frost pre-heat · Freeze protection
- Anti-legionella cycle · Other
Take it to the job
Sequences of operation, error codes and tips work offline in the HVACopedia app.
Source: Glow Brand B85/B120/B160 Installation and Operating Manual (sections 10.2, 11.7, 11.8, 11.10, 12.1). Written in our own words; timings can differ by model and software version, so check the manual for your exact unit.
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.