UTICA BOILERS MGC 3 Series Installation, Operation & Maintenance Manual page 11

WARNING
!
Burn and scald hazard. Safety relief valve could
discharge steam or hot water during operation.
Install discharge piping per these instructions. Failure
to follow these instructions could result in death or
serious injury.
1.
Boiler is shipped assembled. Install discharge piping
from safety relief valve. See Warning, Page 9.
2. Install temperature pressure gauge.
• Apply pipe sealant to threads on shaft of gauge.
• Thread gauge into supply water tee. See Figure 3.
NOTICE
Do not tighten gauge by hand. Gauge should be
tightened using crescent wrench or 9/16" open end
wrench. See Figure 3.
3. Connect supply and return lines to boiler. Connections
may require additional fittings and parts, as shown on
diagrams.
Figure 3 - Temperature Pressure Gauge
4 - CONNECTING SUPPLY AND RETURN PIPING
Verify clean water supply is available to water inlet valve.
Install sand strainer when water supply is from a well or
pump.
Install hot water boiler above radiation level or as required
by Authority having jurisdiction.
Periodic inspection is necessary, as is flushing of float type
devices, per manufacturers specific instruction.
Boiler is factory equipped with low water cutoff.
FOR USE WITH COOLING UNITS
A. Boiler used in connection with refrigeration system, must
be installed so that chilled medium is piped in parallel
with heating boiler. Appropriate valves must be used to
prevent chilled medium from entering heating boiler. See
Figure 5 page 12.
B. Boiler connected to heating coils located in air handling
units where they may be exposed to refrigerated air
circulation, piping system shall be equipped with flow
control valves or other automatic means to prevent
gravity circulation of boiler water during cooling cycle.
LOW WATER TEMPERATURE AND LARGE WATER
CONTENT SYSTEM (See Figures 6 and 7, Page 13.)
Significant condensation may form in boiler and/or venting
system if boiler is operated for long period of time with
return temperatures of less than 120° F.
Condensate is corrosive and can cause severe damage to
boiler and venting system. Minimum design return water
temperature to prevent condensation in boiler and venting
is 120°F. Minimum high limit setting is 140°F.
1.
Boiler used in heating system where design water
temperatures below 140°F are desired (e.g. radiant
floor heating), 4-way mixing valve or suitable
alternative is required to prevent low temperature
return water from entering boiler. Follow mixing valve
manufacturer's instructions.
2. Boiler connected to system having large water content
(such as former gravity system), install system bypass.
See Figures 6 and 7, page 13.
3. If boiler water reset control is used to operate boiler,
minimum reset supply water temperature setpoint
must be at least 140°F, unless mixing valve is used as
in (1) above.
11
PN 240013087 Rev. A [09/30/2020]