HELIX VX-050 Installation, Operation & Maintenance Manual page 77

APPENDIX A - CONTROL MODULE
User Interface Display
Two pump modes are available:
1.
Pump Mode = 0 'CH or CH&DHW'
• In this mode either CH or DHW pump terminal is energized
depending on type of demand (CH or DHW).
• CH and DHW pumps are never energized at the same time.
• In the case of simultaneous call for both CH and DHW, the
energized pump depends on whether the boiler is currently
supplying CH or DHW demand. Refer to DHW Priority
settings below.
• This is typical of hydronic system design with separate CH
and DHW Pumps.
2. Pump Mode = 4 'System Pump'
• In this mode only one external system pump is installed in
hydronic system. This pump will energize independent of
type of demand (CH or DHW).
• Connect this pump to CH/System Pump electrical terminal
block. See page 35 for diagram.
• DHW pump terminal does not function.
• This is typical of hydronic system design which utilizes zone
valves for all CH zones and DHW indirect tank.
Note:
• Pump Mode selection depends on electrical and
hydronic system design. Please refer to sections 5
and 8 for recommended hydronic piping and electrical
configurations.
• Internal heat exchanger pump is energized anytime
demand exists regardless of Pump Mode setting or type
of demand (CH or DHW).
'Service Reminder' feature allows the installer to enable or
disable a service reminder notification on the User Interface at a
predefined interval .
Service reminder does not affect operation of boiler in any way.
It is only a reminder to End User that routine preventative
maintenance is required by qualified service technician.
Allowed Range: 1 to 999 days
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Explanation