Instinct Installation Manual

CHAPTER 4 - BOILER PIPING
21
CAUTION
4.8.1 Expansion Tank and Makeup Water
Ensure the expansion tank is properly sized for the
boiler volume:
• 3 gallons [12 L] for the INSTINCT Combi 155
• 4 gallons [15 L] for the INSTINCT Combi 199
the system water volume, and the system water
temperature.
Undersized expansion tanks will cause system wa-
ter to be lost through the pressure relief valve and
cause additional makeup water to be added to the
system. Eventual boiler heat exchanger failure can
result due to this excessive makeup water addition.
The expansion tank must be located as shown in Fig. 10
on page 20 when using a primary/secondary piping
arrangement. Refer to the expansion tank manufacturer
for additional installation details.
Connect the expansion tank to an air separator only if
the air separator is located on the suction side (inlet)
of the system circulator. Always locate and install the
system fill connection at the same location as the
expansion tank connection to the system.
The expansion tank must be located directly on the
INSTINCT Combi return pipe, before the return check
valve. Incorrect expansion tank location will cause sys-
tem water to be lost through the pressure relief valve
and cause additional makeup water to be added to
the system. Eventual boiler heat exchanger failure can
result due to this excessive makeup water addition.
4.8.2 Diaphragm Expansion Tank
Always install an automatic air vent on top of the air
separator to remove residual air from the system.
4.8.3 Circulator
The INSTINCT Combi is supplied with a Boiler circulator
that provides circulation for central/space heating(CH)
and Domestic Hot Water (DHW) production. See Graph
2 on page 104.
CAUTION
System
Supply
System
Return
T P
Optional Instinct
Combi Timesaver
INSRKIT84
Cold
Water
Fill
Fig. 11 - INSTINCT Combi Near Boiler Piping - Timesaver Manifold
CHAPTER 4