Weather-Rite UHA100 Installation, Operation & Service Manual - page 24
UHA L
OW
P
ROFILE
U
NIT
H
EATER
I
NSTALLATION
O
PERATION AND
S
ERVICE
M
ANUAL
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the rear of the heater cabinet then run the vent
vertically and use a condensate drain at the bottom
of the vertical vent.
Vent pipe must be sloped 1/4'' (.6 cm) for every 1' (.3
m).
For 4'' (10 cm) common vent, an approved vent cap
(P/N 90502102) must be used.
For 6'' (15 cm) common vent, an approved vent cap
(P/N 90502103) must be used.
For common vertical venting of more than two
heaters, See Page 18, Figure 11.
A vent shall not extend less than 2' (.6 m) above the
highest point where it passes through a flat roof of a
building.
7.6 Length Requirements
If using vent lengths greater than 10' (3.0 m),
condensation will form in the vent pipe. Insulation
and additional sealing measures (high temperature
silicone at all seams) are required.
The entire vent should be insulated with foil faced
fiberglass insulation (1/2" thick, 1-1/2# density
minimum).
7.6.1 Maximum Vent Lengths Table
7.7 Vent Material
Vent material may be single wall 26 ga. (minimum)
galvanized steel or equal thickness stainless steel.
Completely seal all joints, refer to Page 14, Section
7.3.
If penetrating a combustible wall or roof, a listed
thimble with 2" (5 cm) clearance must be used.
Where local codes permit, a single section of type
B-1 vent material may be used at the roof or wall
penetration instead of a thimble. Ensure vent
manufacturer's clearance from vent material is
maintained. Seal annular space of the type B-1 vent
as well as all joints in the remaining vent.
7.8 Replacing an Existing Heater in a Venting
System
When replacing an existing heater in a venting
system, the venting system may not be properly
sized to vent the new heater. The following steps
must be followed with each piece of equipment
connected to the venting system placed in
operation, while any other equipment connected to
the venting system are not in operation.
1. Seal any unused openings in the venting
system.
2. Inspect the venting system for proper size and
horizontal pitch, as required by the NFPA 54/
ANSI Z223.1 - latest revision, National Fuel
Gas Code (US) or Standard CSA B149.1
Natural Gas and Propane Installation Code
(Canada) and these instructions. Determine
that there is no blockage or restriction, leakage,
corrosion and other deficiencies which could
cause an unsafe condition.
3. Close all building doors and windows and all
doors between the space in which the piece(s)
of equipment connected to the venting system
are located and other spaces of the building.
Turn on clothes dryers and any exhaust fans,
such as range hoods and bathroom exhausts
so that they shall operate at maximum speed.
Do not operate a summer exhaust fan. Close
fireplace dampers.
4. Follow the lighting instructions. Place the
equipment being inspected in operation. Adjust
thermostat so that the equipment will operate
continuously.
5. For any equipment having a draft hood, test for
draft hood equipment spillage at the draft hood
relief opening after five minutes of main burner
operation. Use the flame of a match or candle.
6. After it has been determined that each piece(s)
of equipment connected to the venting system
properly vents when tested as outlined above,
return doors, windows, exhaust fans, fireplace
dampers and any other gas-burning piece(s) of
equipment to their previous conditions of use.
7. If improper venting is observed during any of
the above tests, the venting system must be
corrected by a contractor qualified in the
installation and service of gas-fired equipment
or your local gas supplier. If the venting must be
resized, use appropriate tables in (US)
Appendix G of NFPA 54/ANSI Z223.1 - latest
revision, National Fuel Gas Code (US) or
Standard CSA B149.1 Natural Gas and
Propane Installation Code (Canada) to
determine minimum size. All vent corrections
must be in accordance with the appropriate
local codes and the NFPA 54/ANSI Z223.1 -
latest revision, National Fuel Gas Code (US) or
Standard CSA B149.1 Natural Gas and
Propane Installation Code (Canada).
Model UHA[X][S]30 - 125
# of Elbows
30 ft (9.1 m)
1
25 ft (7.6 m)
2
20 ft (6.1 m)
3
15 ft (4.5 m)
4
10 ft (3.0 m)
5