HVACopediaFlowMax · Boiler · Domestic hot water
DHW call with pump overrun and priority
What happens, in order
- Hot water draw or storage cylinder call starts the DHW mode (3-way valve moves to DHW)
- Burner modulates to the DHW setpoint
- When the call ends the burner stops and the circulation pump runs on for the DHW overrun time
- DHW priority function (parameter 13) adds a 2 minute delay on the DHW function when switched on
Timings and thresholds
| Item | Value |
|---|---|
| DHW pump overrun (param 8) | 00-90 steps of 5 s, default 18 = 90 s |
| DHW priority delay (param 13) | 2 min when enabled |
| DHW setpoint range | 95-140 F, or 95-160 F with the higher setting |
Codes you may see during this
E06 E12
Applies to: FLOWMAX-120
Models
More FlowMax boiler sequences
- Switch-on and mode selection · Startup
- Heating call with restart delay and pump overrun · Heating
- Heating and DHW frost protection · Freeze protection
- Switched OFF at the control panel · Standby/shutdown
- Flue test and legionella functions · Other
Related
Take it to the job
Sequences of operation, error codes and tips work offline in the HVACopedia app.
Source: FLOWMAX-120 installation manual (DIGITECH PCB SM20021, parameters 4-8, function codes 07/08/28). 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.