Heatrae Sadia HI-MAX INSTANT ID 5-60 Installation, Operation And Maintenance Manual page 16

Figure 18: HI-MAX INSTANT ID Indirect Units - Hydraulic Schematic -
Underfl oor Heating Systems
1
2
3
1 District Return
2 District Flow
3 Cold Water Services

The hydraulic schematics within this document are for guidance only and do not constitute system
design. Some components may not be detailed and connection positions have been moved for clarity purposes.
For clarifi cation of the position of the connections refer to Figure 11 on page 10.

When installing the HIU avoid pipe runs that promote gravitation. Where pipes have to be installed
directly up from a heat source consider piping in an anti-gravity loop (ie, a section of pipe that goes down
before it rises up).

The HI-MAX INSTANT HIU is capable of controlling the temperature to the underfl oor heating manifold,
thus removing the need to fi t a mixing valve as part of the underfl oor heating system. That said, if there are
high temperature circuits in addition to the underfl oor heating system, a mixing valve will still be required as
detailed in Figure 18. A high temperature limit thermostat should also be fi tted.
CAUTION
The HI-MAX INSTANT is suitable to run at high or low heating temperatures. To avoid the risk
of inadvertently damaging fl oors etc, the minimum and maximum temperature range that is
adjustable by the end user MUST be limited by the installer during commissioning.
16
Towel Rail
Room
Sensor
Room
Sensor Underfloor
Controls
Wiring
Room
Centre
Sensor
Room
Sensor
A
MAV
Dynamic balancing valve at the end of each branch to
maintain primary fl ow pipe temperatures during periods
of no demand. Alternatively enable the pulsed fl ow
bypass function on the HI-MAX INSTANT.
FBP
HI-MAX
INSTANT ID
HM1
HM2
HM
S2 S3
P
P1
A
S1
MAV
P