Dunkirk Q95M-200 Modulating Condensing Boiler - Manual (Page 9)

7.2 Supply & Return Lines
See Appendix A for piping examples.
• Packaged boiler set to receive 1¼” NPT return piping
from rear of unit with option for left or right return
connections.
• Use two furnished dielectric unions at boiler supply and
return connections between copper system piping and
boiler. Do not install copper supply and return piping
directly into aluminum boiler casting due to galvanic
corrosion between dissimilar metals.
• 1¼” NPT supply piping exits boiler jacket at top of unit.
• Some boilers supplied with circulator pump and
isolation valves are furnished in a carton inside boiler
cabinet and can be installed at installer preferred
location.
7.1 Clean System First
Before connecting boiler to heating system, clean and flush
system thoroughly. Verify system is free of sediment, flux
and any residual boiler water additives.
Systems having antifreeze not recommended must be
completely flushed to insure no old antifreeze remains. In
older systems obviously discolored, murky or dirty water;
or pH reading outside acceptable range (between 7.0 and
8.0) are indications system should be cleaned or treated.
Thoroughly flush system with clean water to remove any
sediment or contaminants. Sludge and iron oxide deposits
can cause rapid breakdown of inhibitors.
Flushing with clean water. If chemical cleaners are used,
use only those recommended for use with aluminum
boilers. Follow chemical cleaner manufacturer’s instructions
completely.
DO NOT mix different manufacturer’s products.
• When boiler installation is for new heating system,
install all of radiation units (panels, radiators,
baseboard, or tubing) and supply and return mains.
• After all heating system piping and components have
been installed, make final connection of system piping
to boiler.
• Hot water boiler installed above radiation level, or as
required by the Authority having jurisdiction, must be
equipped with low water cut off device. This boiler is
factory equipped with manual reset probe type low
water cutoff.
• Periodic inspection is necessary per low water cut off
manufacturers specific instructions.
7 - NEAR BOILER PIPING
9