Dunkirk DCC-150 - Coaxial Venting Instructions

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 tted with thermostatic
radiator valves, an external by-pass must be tted.
5.8 Central Heating System
Boiler is designed for use in a sealed central heating system.
Design the system to operate with ow 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
• Flow of water will operate the DHW ow 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. (DCC 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 ow to the spark generator and gas valve
creating ignition in the combustion chamber. The ame
sensor will acknowledge the presence of the ame 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 re on its
minimum setting until ow 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
Dunkirk DCC-150 & 205 and DCB 125 & 165 with
indirect tank
240011947 REV B, [03/31/2018]