47
ROOM SOURCED AIR SUPPLY
CAUTION
: Combustion air must not be contaminated by corrosive chemical fumes which can damage
the heater and void the warranty. (Refer to
”Inside Air Contamination” on page 46.)
Water heaters located indoors must be installed in a protective enclosure or properly constructed plant
room with adequate ventilation in accordance with AS/NZS 5601.1.
Ideally, ventilation shall be via two permanent openings DIRECTLY to outside, one at an upper level
and one at low level. Refer to AS/NZS 5601.1 for ventilation requirements and calculations.
WARNING:
Air supply to the area where the water
heater is installed must not be affected by
mechanical exhaust vents such as kitchen or bathroom fans, spa blowers, etc. Mechanical exhaust
vents may create a negative pressure in the area where the water heater is installed and can become
a hazard by asphyxiation, explosion or fire.
NOTE:
Use of this heater in construction areas where fine particulate matter, such as concrete or dry-
wall dust, is present may result in damage to the heater that is not covered by the warranty. If operated
in a construction environment, a clean source of combustion air must be provided directly to the heater.
INDOOR FLUEING
CAUTION:
Proper installation of flue is critical for the safe and efficient operation of the water heater.
Refer to
on page 47 for maximum flue lengths and flue sizes. Under no circumstances is the
flue diameter size to be reduced.
WARNING
: Due to the high operating efficiency of the MVB, the flue gasses may condense in the flue.
The flue MUST be of stainless steel, minimum 316L grade. Use of other materials can result in personal
injury, death or property damage.
WARNING:
Condensate traps and drains for the flue piping are required for installations of the MVB.
The condensate drain must be primed with water to prevent gas flue leak and must be routed to drain
in accordance with local codes and regulations.
WARNING:
The MVB operates with a positive pressure flue. All joints must be sealed to prevent
spillage at the joints which could contaminate the air supply to the water heater.
Support horizontal runs at 1.5m max, use braces for vertical runs and support under or near elbows.
The MVB is supported by a range of stainless steel flue components suitable for positive pressure
condensing operation. Refer to
on page 41 for a list of components.
MVB
Model
Flue
Material
Flue
Size
(mm)
Max. Flue
Length**
(m)
Combustion
Air Intake
Pipe
Material
Max Air Inlet Length** (m)
Ø 150
mm
Ø 200
mm
Ø 250
mm
910500
316L
Stainless
Steel
minimum
150
23
Stainless
Steel,
Galvanized
Steel, PVC,
ABS, CPVC
14
30
N/A
910750
911000
911250
316L
Stainless
Steel
minimum
200
23
Stainless
Steel,
Galvanized
Steel, PVC,
ABS, CPVC
N/A
14
26
911500
911750
912000
**Subtract 3m for every elbow. Max 4 x elbows. Flue terminal not considered as part of the overall
length of the flue system.
Table 17: Vertical and Horizontal Vent & Direct Vent
