HVACopediaHTP · Boiler · Domestic hot water
Indirect water heater call
What happens, in order
- DHW sensor (or aquastat) calls when tank temperature drops below DHW set point by more than the offset
- DHW pump on
- Boiler runs at the boiler DHW supply temperature
- Control checks supply temperature against DHW set point minus differential and shows TEMPER BLOCKING if too hot
- Demand continues until tank is above set point
- DHW pump can run on for the DHW post pump time
- DHW priority limits DHW run time and guarantees a minimum central heat run time
Timings and thresholds
| Item | Value |
|---|---|
| DHW set point | 119 F default |
| DHW differential | 7 F default |
| Boiler supply for DHW | 180 F default |
| DHW post pump | 0 min default (0 to 10) |
| DHW priority | 30 min default (0 to 60) |
Codes you may see during this
Applies to: EL-80, EL-110, EL-150, EL-220, EL-299, EL-399 (N/LP)
More HTP boiler sequences
- Ignition retries and lockout · Ignition
- Central heat call · Heating
- Outdoor reset and warm weather shutoff · Heating
- Pump service mode · Pump/purge
- Standby and over-temperature protection · Standby/shutdown
- Cascade operation · Other
Related
Take it to the job
Sequences of operation, error codes and tips work offline in the HVACopedia app.
Source: Elite EL-80 N Installation Manual (LP-293), p. 43, p. 56, p. 57. 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.