Weil-McLain Electric Water Heater Install system water piping space heating, Boiler circulator

PLUS Line Instruction Manual Supplement

PLUS & PLUS WATER HEATERS WITH GAS-FIRED WATER BOILERS

1 Install system water piping (space heating)

System water piping methods

Figure 1 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 Ultra 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 Ultra 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 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 addition.

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 connection at the same point as the expansion tank connection to the system.

4.The piping drawings in this supplement show diaphragm expansion tanks. See Figure 1 for piping from air separator to expansion tank and make-up water line using a closed-type expansion tank.

5.Refer to Ultra 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.

Closed-type expansion tank

1.See Figure 1 for piping connections when using a closed-type expansion tank.

2.Pitch any horizontal piping up towards tank 1 inch per 5 feet of piping. Connect to tank with at least ¾" piping to allow room for air to rise.

DO NOT install automatic air vents on closed-type expansion tank systems. Air must remain in the system and return to the tank to provide its air cushion. An automatic air vent would cause air to leave system, resulting in water-logging the expansion tank.

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. The boiler circulator is selected to ensure adequate flow through the Ultra boiler. Failure to comply could result in unreliable performance and nuisance shutdowns from insufficient flow.

Sizing space heat system piping

1.See Figures 2 and 3, pages 4 and 5, or the Ultra Boiler Manual for recommended piping. In all diagrams, the space heating system is isolated from the boiler loop by the primary/secondary connection.

2.Size the piping and components in the space heating system using recognized design methods.

Part number IWHA016A/1103 3