Pentair MT125 - Horizontal or Vertical Venting Flexible Duct (Flex-Vent)

MASTERTEMP 125 Pool and Spa Heater Installation and User’s Guide 460906 Rev. D 8/2020
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HORIZONTAL OR VERTICAL VENTING FLEXIBLE DUCT (FLEX-VENT)
NOTE: THE ALLOWABLE VENT RUNS FOR EACH VENT PIPE DIAMETER ARE DIFFERENT AND CAN
NOT BE EXCEEDED.
It is recommended that vent runs over 5.4 m (18 ft) may need to be insulated to reduce condensation related problems
and/or the use of a condensate trap in the vent run close to the heater may be necessary in certain installations such
as cold climates. Horizontal vents 1 m (3 feet) or less in length do not require a condensate tee. The MasterTemp
heater is suitable for through-the-wall venting. See Table 7 for maximum permissible Flexible Vent lengths.
Table 7.
Flexible Vent Sec-
tion
Figure 25.
110 mm (4.33 in)
Radius Minimum
MINIMUM FLEX BEND RADIUS
150 mm (6 in.) or 102 mm (4 in)
Special Gas Vent
(Vertical or Horizontal)
*
No. of 90° Elbows
Maximum Length in
Feet (M)
0 11.6 m (38 ft.)
1 8 m (26 ft.)
*
Minimum vent length is 0.34M (1 ft.) or in
accordance with vent manufacturer’s instruction,
and local and national codes. Horizontal vents
1 m (3 in) or less in length do not require a
condensate tee, but must slope down toward the
outlet at 2 cm to the meter (1/4 in / ft.) to allow
condensate to drain.
CAUTION
Do NOT combine exhaust vent pipes to a
common exhaust vent in multiple unit installa-
tions. Run separate vent pipes.
See Figures 22, 23 (page 29) and 25
Section 1. Installation Instructions
NOTE: KEEP A 150 CM (6 IN) MINIMUM CLEARANCE BETWEEN THE VENT PIPE AND
COMBUSTIBLE SURFACES. FOLLOW THE VENT MANUFACTURER’S INSTRUCTIONS
AND CODE REQUIREMENTS.
Each 90° bend reduces the maximum horizontal vent run by 3.6 m (12 feet) and each 45° bend in the vent
run reduces the maximum vent run by 1.8 m (6 feet). See Table 7) for the maximum vent length using one 90°
bend.
NOTE
After installation, installer must check for correct and safe operation of the heater.