Lochinvar SMART SYSTEM 502 - 2072 - Manual (Page 17)

1
Service
(continued)
17
Copper-fin II/IIE Boiler, Water Heater and Pool Service Manual
E5: SH/DHW switching time (boiler only)
When a SH call for heat and a DHW call for heat are present
at the same time, the SMART SYSTEM control can switch back
and forth between the two calls. The time that the control
services the SH demand before switching to the DHW demand
can be adjusted by using parameter E5. The range of this
parameter is 0 to 240 minutes. Setting this parameter to 0
disables the switching function. The control will service the
DHW demand until it ends, then return to the SH demand (if
active). The default value of this parameter is 30 minutes.
E6: DHW/SH switching time (boiler only)
The time that the SMART SYSTEM control services a DHW
demand before returning to the SH demand is set by parameter
E6. The range of this parameter is 0 to 240 minutes. Setting
this parameter to 0 disables the switching function. The default
value of this parameter is 30 minutes.
E7: Tank offset (water heater only)
The tank offset is the number of degrees the DHW tank
temperature must go above the tank set point before the water
heater will turn off. To adjust this value, access parameter E7.
The temperature range of this parameter is 0° to 10°F (5°C).
The default value is 4°F (2°C).
E8: Tank differential
The tank differential is the number of degrees the DHW tank
temperature must go below the tank set point before the heater
or boiler will start to heat the DHW tank. To adjust this value,
access parameter E8. The temperature range of this parameter
is 0° to 40°F (22°C). The default value is 6°F (3°C).
D5: Freeze protection pump on
In order to prevent the water in the heater from freezing, the
SMART SYSTEM control turns on the boiler pump whenever
the inlet temperature goes below the minimum temperature.
This temperature can be adjusted by using parameter D5. The
range of this parameter is 32°F (0°C) to 104°F (40°C). The
default value is 45°F (7°C).
D6: Freeze protection burner on
If the inlet temperature continues to drop after strating
the pump (see Freeze Protection Pump On), and the inlet
temperature goes below a second minimum temperature, the
first stage will fire. This second temperature can be adjusted by
using parameter D6. The temperature range of this parameter
is 32°F (0°C) to 104°F (40°C. The default value is 37°F (3°C).
D7: Freeze protection differential
Once the pump has turned on, this parameter determines how
much the inlet temperature must rise before the pump turns
off. Similarly, once Stage 1 has turned on, this parameter also
determines how much the inlet temperature must rise before
Stage 1 turns back off. This temperature differential can be
adjusted using parameter D7. The temperature range of this
parameter is 0° to 72°F (40°C). The default temperature is 5°F
(3°C).
E: DHW settings
E1: DHW tank set point
When a temperature sensor is installed in the DHW tank, the
DHW tank set point sets the target temperature of the water
in the tank. The user or installer can adjust this set point
by accessing parameter E1. The temperature range of this
parameter is 60°F (15°C) to 190°F (88°C). The default value is
120°F (49°C).
E2: DHW boiler set point (boiler only)
When an indirect DHW call for heat becomes active, the control
will use the DHW boiler set point to determine the firing rate
of the unit based on the actual outlet water temperature.
This parameter can be changed by the installer by accessing
parameter E2. The temperature range of this parameter is 32°F
(0°C) to 261°F (127°C). The default value is 180°F (82°C).
E3: Minimum tank set point
The minimum allowable tank set point can be adjusted using
parameter E3. The temperature range of this parameter is 60°F
(16°C) to the value of parameter E4. The default value is 60°F
(16°C).
E4: Maximum tank set point
The maximum allowable tank set point can be adjusted using
parameter E4. The temperature range of this parameter is
60°F (16°C) to the value of parameter E3 to 190°F (88°C). The
default temperature is 190°F (88°C).