6
• When communicating with outdoors by means of vertical ducts, each
opening shall have a free area of not less than one square inch per
4,000 Btu per hour (551 mm
2
/kW) (35 square inches per gallon of oil
consumed per hour) of total input rating of all appliances in the enclosure.
• If horizontal ducts are used, each opening shall have a free
area of not less than one square inch per 2,000 Btu per hour
(1,101 mm
2
/kW) (70 square inches per gallon of oil consumed per
hour) of total input of all appliances in the enclosure, fig. 5.
FIGURE 5.
FLUE GAS VENTING
In the absence of any local codes, regulations, or vent pipe or chimney
manufacturer's recommendations, for oil fired equipment, follow the
suggestions below for designing and installing a venting system.
For these water heaters, it is recommended that an adequate chimney be
used for venting the flue gases. Type B, double wall, vent pipe should be
used as the vent connector pipe. However, where no chimney is available,
vent pipe may be used to construct a vent.
Where an existing chimney or vent is to be used, be sure that the chimney
or vent has adequate capacity for the number and sizes of appliances
being vented through it. Inspect the chimney or vent and remove all soot
or other obstructions which will retard free draft.
VENT CONNECTOR AND DRAFT REGULATOR
The chimney or vent connector diameter should be the same size as the
heater flue outlet, see Table 4. A minimum rise of 1/4" per foot (21mm/M)
of horizontal connector length must be maintained between the heater
and chimney opening, fig. 6. The connector length should be kept as
short as possible.
TABLE 4. SUGGESTED VENT CONNECTOR SIZES
Outlet Diameter
Model Number
Inches
(mm)
GPO 86-199*
6
152.4
GPO 86-245
8
203
GPO 84-315/315A
8
203
GPO 75-385/385A
8
203
GPO 75-455/455A
8
203
GPO 69-700/700A
10
254
* These models are factory supplied with a flue reducer which should
be installed on the top cover.
In venting systems where a continuous or intermittent back (positive) draft
is found to exist, the cause must be determined and corrected. In some
cases, a special vent cap may be required.
If the back draft cannot be corrected by normal methods or if a suitable
draft cannot be obtained, additional make up air must be provided to the
room to assure proper venting and combustion.
Note: A negative draft must be maintained in the vent piping.
The barometric draft regulator must be installed in the same room
as the heater, fig. 6. Locate the regulator as close as possible to
the heater and at least 18" (457.2 mm) from a combustible ceiling
or wall. A manually operated damper should not be placed in the
chimney connector.
PROPER VENT CONNECTOR INSTALLATION
FIGURE 6.
CHIMNEY
The oil-fired water heater must be connected to a chimney built in
accordance with accepted building code practice or listed factory built type,
Table 5. The exit point of the chimney flue gas must be at least 3' (0.91
M) above the highest point where it passes through the roof of a building.
Also, it must be at least 2' (0.61 M) higher than any portion of a building
within 10' (3.05 M) of the chimney.
MULTIPLE HEATER FLUES
When two or more oil-fired water heaters are connected to a single chimney
or vent there shall be sufficient draft available for safe combustion and
removal of combustion products to the outdoors from each heater. Refer
to local codes for connection details.
Only one oil-fired water heater should be connected to any one type L
venting system.
A draft regulator shall be provided for each oil-fired water heater in a
multiple heater system.
DANGER
INCORRECT INSTALLATION CAN CAUSE IMPROPER OPERATION,
FIRE,
ASPHYXIATION, SERIOUS PERSONAL INJURY OR DEATH. NEVER
OPERATE THIS WATER HEATER UNLESS IT IS PROPERLY VENTED
TO THE OUTDOORS AND HAS ADEQUATE COMBUSTION AIR SUPPLY.
Oil Equivalent Output Square & Rectangle
Firing Heat Input Heat Stack
Round Stack Minimum
Model
Rate
Rate Rate Dimension Diameter Height
Number
(GPH) (LPH) Btuh kW Btuh kW Inches
mm
Inches mm
Feet Metres
GPO 86 -199
1.42
5.38
199,000 58 159,200
47 8 1/2 X 8 1/2 216 x 216
9
228.6
20
6.1
GPO 86 -245
1.75
6.62
245,000 72 196,000
57 8 1/2 X 8 1/2 216 x 216
9
228.6
20
6.1
GPO 84-315 (A)
2.25
8.52
315,000 92 252,000
74
8 1/2 X 13
216 x 330
10
254
30
9.1
GPO 75 -385 (A)
2.75
10.41 385,000 113 308,000
90
8 1/2 X 13
216 x 330
10
254
30
9.1
GPO 75 -455 (A)
3.25
12.30 455,000 133 364,000 107
13 X 13
330 x 330
12
304.8
35
10.7
GPO 69 -700 (A)
5
18.93 700,000 205 560,000 164
13 X 18
330 x 457
14
355.6
40
12.2
TABLE 5. USUAL CHIMNEY SIZES FOR UNITS
