CAC / BDP BW4BAH-91, Installation, Operation & Maintenance Manual

9

1. 

Installation of boiler for new heating system, 

Install all of radiation units (panels, radiators, 

baseboard, or tubing) and supply and return mains 

fi

 rst. After all heating system piping and components 

have been installed, make 

fi

 nal connection of system 

piping to boiler. It is recommended to mount circulating 

pump on supply side piping, such that it pumps away 

from expansion tank. Refer to 

fi

 gures on next pages.

2. 

Equip hot water 

boiler installed above radiation 

level

 with low water cut off device. Periodic inspection 

is necessary, as is 

fl

 ushing of 

fl

 oat type devices, per 

low water cut off manufacturer’s speci

fi

 c instructions.

3. 

Packaged boiler is set up with 1¼” NPT supply 

and return piping 

from front of boiler. Boiler supply 

and return piping can be moved to rear of boiler. Boiler 

should not be piped return line to front, supply line 

to rear, or vice versa, will cause boiler water to short 

circuit heat exchanger. Piping connections may require 

additional 

fi

 ttings and parts.

4. 

Install drain valve 

provided with boiler in return tee. .

5. 

Install Safety Relief Valve 

in rear section using ¾” 

nipple and street elbow provided with boiler. See 

fi

 gure 

6a.
A.  Install safety relief valve with spindle in vertical 

position.

B.  Do not install shutoff valve between boiler and 

safety relief valve.

C.  Install discharge piping from safety relief valve.  

• Use ¾” or larger pipe. See 

fi

 gure 6b.

• Use pipe suitable for temperatures of 375°F 

(191°C) or greater.

• Individual boiler discharge piping shall be 

independent of other discharge piping.

• Size and arrange discharge piping to avoid 

reducing safety relief valve relieving capacity 

below minimum relief valve capacity stated on 

rating plate.

• Run pipe as short and straight as possible to 

location protecting user from scalding and properly 

drain piping.

• Install union, if used, close to safety relief valve 

outlet.

• Install elbow(s), if used, close to safety relief valve 

outlet and downstream of union (if used).

• Terminate pipe with plain end (not threaded).

6. 

Verify clean cold water supply is available 

when 

connecting

to pressure reducing valve. When water 

supply is from well or pump, a sand strainer should be 

installed at the pump.

SYSTEM PIPING

Figure 6a - Safety Relief Valve Installation

Follow Instructions 

to install discharge 

piping from safety 

relief valve to drain.

Check local 

codes for 

maximum 

distance 

from fl oor 

or allowable 

safe point of 

discharge

.

SAFETY RELIEF VALVE

DISCHARGE 

LINE

Figure 6b - Discharge Piping From Safety Relief 

Valve