How a Boiler Control Works
Figure 19 - Cold Start Operation (Low Limit ► OFF)
150 | 175 |
200 | |
125 | 225 |
100 | 250 |
75 | 275 |
High Temperature Differential
(Adjustable 5° to 45°F)
Starts the burner when temperature drops to the HIGH LIMIT DIFFERENTIAL setting.
High Temperature Limit
(Adjustable 100° to 240°F)
Shuts burner off at HIGH LIMIT set point.
Example Shown:
High Limit = 200°
Differential = 20°
During a call for heat, the burner will be shut off at 200° and be turned back on at 180°
50300
Figure 20 - Warm Start Operation (Low Limit ► ON) (To maintain domestic hot water temperature)
Low Temperature Differential
(Adjustable 10° to 45°F)
Shuts burner off when temperature rises to the LOW LIMIT DIFFERENTIAL setting.
High Temperature Differential
(Adjustable 5° to 45°F)
Starts the burner when temperature drops to the HIGH LIMIT DIFFERENTIAL setting.
Low Temperature Limit
(Adjustable 100° to 220°F)
Starts the burner at LOW LIMIT set point.
Example Shown:
Low Limit = 140°
Differential = 10°
During the OFF cycle with no call for heat, the burner is turned on at 140° to maintain the boiler water temperature and is shut off at 150° (140°+10°).
175
150 200
125225
100 | 250 |
75 | 275 |
High Temperature Limit
(Adjustable 100° to 240°F)
Shuts burner off at HIGH LIMIT set point.
Example Shown:
High Limit = 200°
Differential = 20°
During a call for heat, the burner will be shut off at 200° and be turned back on at 180°
50300
AquaSmart Boiler Control Manual
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