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XIII. Operation F. Changing Adjustable Parameters (continued)
“Press” button to access the following parameters:
Factory
Setting
Range / Choices Parameter and Description
120F
(49C)
105F - 140F
(41C - 60C)
Domestic Hot Water Setpoint
During a DHW demand, the boiler will attempt to maintain this temperature at the DHW sensor
located just upstream of the hot water outlet connection. Under certain conditions, such as very
low ow rates and transitions from a space heating space heating demand, the DHW temperature
may signicantly exceed this set-point. For this reason, an installer supplied tempering valve is
required for all installations (see Warnings on Page 80 and below). This tempering valve should
be set to the value desired at xtures. In general, the DHW set point should be set just far enough
above the tempering valve set-point for the tempering valve to regulate temperature properly (see
tempering valve instructions).
60
30 to 120
Minutes
Priority Time
This boiler can only respond to one demand (either space heat or domestic hot water) at a time.
When there are simultaneous calls for space heat and domestic hot water, the domestic hot water
demand will have priority for the duration of this “Priority time”. At the end of that time, the boiler
will respond to the call for space heat and no domestic hot water will be available until there is
an interruption in one of the two demands. During the priority time itself any interruption in the
DHW or space heat demand will also “reset the clock”; both demands need to be present on a
continuous basis for the priority time to expire.
DANGER
Water temperature over 125°F (52°C) can cause severe burns instantly or death from scalds.
• Installation of an ASSE 1017 or ASSE 1070 certied tempering valve is REQUIRED as part of the
installation of this boiler (see Section X). This valve serves as the primary means of regulating water
temperature supplied to xtures.
• When making adjustments to the tempering valve and/or the domestic water set point, observe the
relationship between domestic water temperature and time required for scalding to occur shown
in Table 13.3. Also keep in mind that children, disabled and the elderly are at highest risk of being
scalded.
Table 13.3: Approximate Time/Temperature Relationships For Scalding
120°F More than 5 minutes
125°F 1-1/2 to 2 minutes
130°F About 30 seconds
135°F About 10 seconds
140°F Less than 5 seconds
145°F Less than 3 seconds
150°F About 1-1/2 seconds
155°F About 1 second
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