11
> LOW DESIGN WATER TEMPERATURE
SYSTEMS
> LARGE WATER CONTENT SYSTEMS
> PIPING ARRANGED FOR “POWER
PURGING” AIR OUT OF THE SYSTEM
PIPING, REFER TO THIS MANUAL’S
SECTION ON “FILLING THE SYSTEM
WITH WATER” OPTION #1
SYSTEM PIPING
Figure 7 - Bypass Piping Arrangement Diagram
Low Design Water Temperature Systems (Below 140°
F) And Large Water Content Systems
•
Significant condensation may form in this boiler and/
or venting system if boiler is operated with return
temperatures of less than 120°F.
•
Condensation is corrosive and can eventually cause
damage to boiler and venting system. Minimum design
return water temperature to prevent this condensation in
boiler and venting is 120°F.
•
Boiler used in heating system where design water
temperatures below 140°F are desired (e.g. radiant floor
heating), a 3-way or 4-way mixing valve or suitable
alternative (e.g. Bypass Piping Arrangement shown in
Figure 7 ) is required to prevent low temperature (below
return 120°F) return water from entering boiler. When
using mixing valve, follow manufacturer’s installation
instructions.
•
Boiler connected to system having large water content
(such as former gravity system), use of Bypass Piping
Arrangement shown in diagram on following page is
suggested.
PN 240013012, Rev. B [12/15/2020]
