8
Table 3 – Boiler Rating Information
BOILER MODEL
BURNER FIRING RATE
INPUT (MBH)
TANKLESS RATING (GPM)
BW4BAH091
BW4RAH091
BW5BAH091
BW5RAH091
0.65
91
2.90
BW4BAH105
BW4RAH105
BW5BAH105
BW5RAH105
0.75
105
3.00
BW4BAH140
BW4RAH140
BW5BAH140
BW5RAH140
1.00
140
3.25
BW4BAH126
BW4RAH126
BW5BAH126
BW5RAH126
0.90
126
3.15
BW4BAH175
BW4RAH175
BW5BAH175
BW5RAH175
1.25
175
3.50
BW4RAH210
BW4BAH210
BW5RAH210
BW5BAH210
1.50
210
3.75
BW4BAH168
BW5BAH168
1.20
168
3.45
BW4BAH245
BW4RAH245
BW5BAH245
BW5RAH245
1.75
245
4.00
BW4BAH280
BW4RAH280
BW5BAH280
BW5RAH280
2.00
280
4.25
* Gallon of water per minute heated from 40
_
F to 140
_
F with 200
_
F boiler water, intermittent draw. Tankless heater is factory installed on BW5 models, field
installed accessory on BW4 models.
TEMPERED
HOT WATER
UNTEMPERED
HOT WATER
(TO AUTOMATIC
DISHWASHER, ETC.)
SHUTOFF
VALVE
COLD WATER
INLET
IN
OUT
TANKLESS COIL
LIMIT
CONTROL
CENTER LINE
OF COLD TAP
8 IN. TO
12 IN.
TEMPERING
VALVE
A98269
Fig. 8 -- Recommended Piping with Tankless Heater Coil
Installation System Piping
1. Place boiler in selected location as close to flue as
possible. (See Fig. 4.) Boiler is shipped assembled. Only
the factory--supplied relief valve needs be installed.
2. Install relief valve in rear section on 3/4--in. nipple and
street ell. Do not connect directly to a drain, but leave an
air gap. No shutoff of any description shall be placed
between safety relief valve and boiler, or on discharge
pipes between such safety valves and the atmosphere.
Installation of safety relief valve shall conform to
requirements of the ANSI/ASME Boiler and Pressure
Vessel Code, Section IV. The manufacturer is not
responsible for any water damage. Connect a drain line of
the same pipe size (3/4--in.) to carry any water away to a
drain.
3. Connect the 1 1/4--in. NPT supply and return lines to
boiler. Both supply and return lines should be piped to the
front section or both to the rear section. The boiler should
NOT be piped return line to the front, supply line to the
rear, or vice versa, as this will cause boiler water to short
circuit heat exchanger. The connections may require
certain additional fittings and parts as shown on diagrams.
(See Fig. 9, 10, and 11.)
If installing an entire new heating system, first install all radiation
units (panels, radiators, or cabinets) and supply and return mains,
then make connections to boiler.
In connecting cold water supply to reducing valve, make sure that
a clean water supply is available. When water supply is from a
well or pump, a sand stainer should be installed at pump.
When boiler is used in connection with refrigeration systems, it
shall be installed so that chilled medium is piped in parallel with
the heating boiler with appropriate valves to prevent chilled
medium from entering the heating boiler.
The minimum boiler supply water temperature setting on the
aquastat is 140
_
F. If the boiler is used in a heating system where
supply water temperatures below 140
_
F are desired, a suitable
method, such as, the use of bypass piping shown in the figure 10,
a 3 way or 4 way mixing valve, or some other means needs to be
used to ensure return water temperatures to the boiler are no less
than 120
_
F. When the boiler is operated with return water
temperatures less than 120
_
F, condensation may form in the
boiler and venting. This condensation is corrosive and can
eventually cause severe damage to the boiler and venting system.
Antifreeze added to boilers must be non--toxic and must be of a
type specifically intended for use in closed hydronic heating
systems. Under no circumstances should automotive antifreeze be
used. Antifreeze used in any boiler may reduce capacity by 10
percent or more and increase fuel consumption. Tankless coil
performance will fall as concentration of antifreeze is increased.
Refer to boiler and piping water volumes tables on next page.
BW
4
/BW
5
