Weil-McLain GOLD DV WATER BOILER manual IIIc Water piping — boiler connections, Air separator

GOLD GV Water boiler series 3 — manual

IIIc Water piping — boiler connections

Supply & return connections

Always connect supply and return connections to the boiler as shown in Figure 9. (Note in the following and in the suggested piping drawings in this manual that the expansion tank and air separator location will depend on the system piping.)

Operating pressure of system, after temperature expansion above cold fill pressure, should not exceed 24 PSIG to avoid weeping of relief valve.

Install an automatic air vent on top of the air separator, per separator manufacturer’s instructions.

Closed-type expansion tank:

Air separator

Install an air separator in the piping as shown. For single-zone systems, install the air separator in the return piping as shown in Figure 9. This allows mounting the automatic air vent and expansion tank off of the separator.

Expansion tank

Figures 9 and 10 show typical installation of the expansion tank when the boiler is connected to a zone- valve zoned baseboard system (see Figure 10). Always locate the air separator and expansion tank as shown in the suggested piping drawings, Figures 10 through 16.

Ensure that the expansion tank size will handle boiler and system water volume and temperature. See tank manufacturer’s instructions and ratings for details. Additional tanks may be added to the system if needed to handle the expansion. These tanks may be installed by connecting to tees in the system piping.

Undersized expansion tanks

cause system water to be lost from the relief valve and makeup water to be added through the fill valve. Eventual section failure can result.

Always locate the cold water fill connection at the expansion tank. Never locate this elsewhere in the system.

Diaphragm- or bladder-type tank:

Refer to Figure 9 for suggested piping when using a diaphragm- or bladder-type expansion tank.

Diaphragm- or bladder-type expansion tank — Control fill pressure with the tank air charge pressure. Always check pressure and charge tank with tank removed from system to be sure reading is accurate. Boiler relief valve is set for 30 PSIG.

Figure 10 shows suggested piping when using a closed- type expansion tank, in which the air is directly in contact with tank water.

Connect piping (½" or ¾") from the air separator top outlet to the tank fitting. Slope any horizontal piping a minimum of 1 inch per 5 feet of horizontal pipe.

Always use a tank fitting, such as the B&G Tanktrol or Taco Taco-Trol(shown). The fitting reduces gravity flow of water in the piping to the tank, avoids air bubbling through the tank water, and provides the proper fill height in the tank.

Correct all leaks in the system or tank piping. Leaks allow air to escape from the system and will cause water- logging of the tank. This will result in water loss through the boiler relief valve due to over-pressurization.

NEVER use an automatic air vent in a system equipped with a closed-type expansion tank. The air removed from the system will cause water- logging of the expansion tank.

Closed-type expansion tank — Follow tank manufacturer’s instructions for filling the tank. Typical tank sizing provides for approximately 12 PSIG when the tank is filled to the normal level and system water is cold. Note that boiler relief valve is set for 30 PSIG. Operating pressure of system, after temperature expansion above cold fill pressure, should not exceed 24 PSIG to avoid weeping of relief valve.

Backflow preventer

Where required by codes, install a backflow preventer in the cold water fill line, as shown in suggested piping diagrams on following pages. Install a check valve if a backflow preventer is not installed.

28 Part number 550-141-850/0699