System water piping methods, Boiler circulator | Weil-McLain PLUS-E017-A/1206

Install system water piping (space heating)

Manual • Installation • Start-Up • Usage • Maintenance • Parts

B1		gas

	Install system water piping (space heating)

System water piping methods

Figure 11 Expansion tank piping

All piping methods shown in this manual use primary/secondary connection to the boiler loop. These designs ensure proper

flow through the Gas boiler, for the most efficient and reliable operation of the boiler and the heating system. For other piping methods, consult your local Weil-McLain representative or refer to

separate Gas boiler piping guides.

Wall-mounted boilers — Piping can exit bottom of boiler enclosure. See separate wall-mounting instructions for details.

Expansion tank and make-up water

1.Ensure expansion tank size will handle boiler and system water volume and temperature. Allow 3 gallons for the boiler and its piping.

Undersized expansion tanks cause system water to be lost from relief valve and make-up water to be added through fill valve. Eventual boiler failure can result due to excessive make-up water addi- tion.

2.Tank must be located as shown in this supplement, or following recognized design methods. See tank manufacturer’s instructions for details.

3.Connect the expansion tank to the air separator only if the separator is on the suction side of the system circulator. Always install the system fill con- nection at the same point as the expansion tank connection to the system.

4.The piping drawings in this manual show only diaphragm expansion tanks. Use only bladder-type or diaphragm-type tanks with PLUS indirect water heater applications.

5.Refer to the Boiler Manual for other system piping examples.

Diaphragm (or bladder) expansion tank

1.Always install an automatic air vent on top of the air separator to remove residual air from the system.

2.See Figure 11 for correct location of the expansion tank.

DO NOT USE a closed-type expansion tank

The boiler-side piping must be equipped with a diaphragm- or bladder-type expansion tank, NOT a closed-type expansion tank. This is necessary to allow venting air from the top of the indirect water heater boiler-side.

Boiler circulator

The boiler circulator is shipped loose. It must be located in either the return or supply piping, as shown in the appropriate piping diagram in this supplement or the Boiler Manual.

DO NOT use the boiler circulator in any location other than those shown in this manual or the boiler manual. The boiler circulator is selected to ensure adequate

flow through the boiler. Failure to comply could result in unreliable per- formance and nuisance shutdowns from insufficient flow.

Sizing space heat system piping

1.See Figures 12 and 13, pages 26 and 27, or the Gas Boiler Manual for recommended piping. In all diagrams, the space heating system is isolated from the boiler loop by the primary/secondary connec- tion.