Operating instructions

17
Boiler Piping
Closed-Type Expansion Tank
It is recommended to pitch any horizontal pip-
ing upwards toward the expansion tank 1 inch
per 5 feet [2.5cm / 1.5 M] of piping. Use 3/4”
piping to the expansion tank to allow air with-
in the system to rise.
DO NOT install automatic air vents on a
closed-type expansion tank system. Air
must remain in the system and be
returned to the expansion tank to pro-
vide an air cushion. An automatic air
vent would cause air to be vented from
the system resulting in a water-logged
expansion tank.
Circulator
The CHALLENGER must be supplied with a
Central Heating (CH) circulator with flow
check. The circulator when wired directly to the
CHALLENGER will allow for domestic hot
water priority and to provide circulation for the
freeze protection feature of the boiler control.
See Graph 5-10 on page 79-81 for pressure drop
and minimum flow rate through the boiler.
Sizing Primary Piping
See Fig. 7 and 8, page 20, for recommended
piping arrangements based on various applica-
tions. Size the piping and system components
required in the space heating system, using rec-
ognized design methods.
System Piping - Zone Circulators
Connect the CHALLENGER to the system
piping as shown in Fig. 7 page 20 when zoning
with zone circulators.
The installer must provide a separate circulator
for each zone of space heating.
To ensure an adequate flow rate through
the CHALLENGER, the boiler supply
and return piping size must be a mini-
mum of 1 inch.
System Piping - Zone Valves
Connect the CHALLENGER to the system pip-
ing as shown in Fig. 8 page 20 when zoning with
zone valves. The primary / secondary piping
ensures that the boiler loop has sufficient flow.
To ensure an adequate flow rate through
the CHALLENGER, the boiler supply
and return piping size must be a mini-
mum of 1 inch.
CAUTION
NOTICE
NOTICE