21
5 - HYDRONIC PIPING
Pressure gauge
- to indicate the system pressure to be
maintained.
By-pass
- Boiler incorporates an automatic by-pass,
However, where all radiators are fitted with thermostatic
radiator valves, an external by-pass must be fitted.
5.8 Central Heating System
Boiler is designed for use in a sealed central heating system.
Design the system to operate with flow temperatures of up to
176°F (80° C), take pump head, expansion tank size, mean
radiator temperature, etc. into account.
Boiler is supplied with the following components: Pressure
relief valve - 30.0 psi (2.1 bar). Boiler internal pressure switch
will shut boiler off at 43.5 psi /3.0 bar.
5.9 Domestic Hot Water Mode
Utica Boiler MAC-150 & 205 and MAH-125 & 165 with
indirect tank
•
Flow of water will operate the DHW flow switch which
requests the 3 way valve to change position. This will allow
the pump to circulate the primary water through the DHW
plate heat exchanger. (MAC-150 & 205 only)
• Combustion fan will then come on and begin to run at
ignition speed.
• Once the fan reaches ignition speed the control board will
allow power to flow to the spark generator and gas valve
creating ignition in the combustion chamber. The flame
sensor will acknowledge the presence of the flame in the
combustion chamber and send a signal to the control
board.
• Temperature sensors will send a signal to the control board
allowing the control board to increase/ decrease the speed
of the fan. The combustion fan will in turn modulate the
gas rate accordingly.
• When the domestic hot water demand ceases the burner
will extinguish, unless there is a demand for central
heating.
5.10 Frost Protection Mode
Frost protection mode is integrated into the appliance when
left in domestic hot water or central heating position. If the
temperature falls below 41°F / 5° C boiler will fire on its
minimum setting until flow temperature of 86°F / 30° C is
reached.
5.11 Pump Protection
Pump will automatically operate for 1 minute in every 24 hours
to prevent seizing.
WARNING
Burn, Scald Hazard! Water temperature over 125°F
(51°C) can cause severe burns and scalding. See
User's Manual before setting water temperature.
Failure to follow these instructions could result in death
or serious injury.
!
• Priority is given to the domestic hot water supply.
Demand at tap or shower will override any central heating
requirement.
FIGURE 5-7
240011941 REV B, [03/31/2018]
Summary of Contents for MAC-150
Page 2: ...MAC 205 ...
Page 4: ...MAH 165 ...
Page 65: ...61 APPENDIX A WIRING DIAGRAMS A 1 MODELS 125 Heat Only 240011941 REV B 03 31 2018 ...
Page 66: ...62 APPENDIX A WIRING DIAGRAMS A 2 MODELS 165 Heat Only 240011941 REV B 03 31 2018 ...
Page 67: ...63 APPENDIX A WIRING DIAGRAMS A 3 MODELS 150 Combi 240011941 REV B 03 31 2018 ...
Page 68: ...64 APPENDIX A WIRING DIAGRAMS A 4 MODELS 205 Combi 240011941 REV B 03 31 2018 ...
Page 69: ...65 NOTES 240011941 REV B 03 31 2018 ...
Page 70: ...66 NOTES 240011941 REV B 03 31 2018 ...
Page 81: ...9 125 WITH ZONE CIRCULATOR PUMPS 125 with Zone Circulator Pumps PN 240011430 REV G 03 31 18 ...
Page 84: ...12 125 WITH ZONE VALVES PIPING DIAGRAM 125 with Zone Valves PN 240011430 REV G 03 31 18 ...
Page 90: ...18 165 with Zone Valves 165 WITH ZONE VALVES PIPING DIAGRAM PN 240011430 REV G 03 31 18 ...
Page 94: ...22 150 205 WITH ZONE PUMPS WIRING DIAGRAM 150 205 With Zone Pumps PN 240011430 REV G 03 31 18 ...
Page 102: ...30 MODEL 125 Heat Only 125 HEAT ONLY WIRING DIAGRAM PN 240011430 REV G 03 31 18 ...
Page 103: ...31 MODEL 165 Heat Only 165 HEAT ONLY WIRING DIAGRAM PN 240011430 REV G 03 31 18 ...
Page 104: ...32 MODEL 150 Combi 150 COMBI WIRING DIAGRAM PN 240011430 REV G 03 31 18 ...
Page 105: ...33 MODEL 205 Combi 205 COMBI WIRING DIAGRAM PN 240011430 REV G 03 31 18 ...
Page 110: ...38 Low Water Cutoff Detail LOW WATER CUTOFF NO NO YES PN 240011430 REV G 03 31 18 ...
Page 111: ...39 NOTES PN 240011430 REV G 03 31 18 ...
Page 112: ......
Page 115: ......
