Weil-McLain 550-141-396/0801 Pre-installation, General instructions, Locating the boiler

PER Series 3 Electric-Hydronic Boilers Installation Instructions

Pre-installation

General instructions

The Weil-McLain Model PER electric-hydronic boilers are assembled units designed for use in forced hot water heating systems. The suggested design temperature rise through the boiler is 20°F. The PER boiler is a complete package including the circulator and expansion tank.

Low flow rates through the boiler at elevated temperatures should be avoided. The structure to be heated should be insulated in the conventional manner used in your area for electrically heated buildings. Boiler must be installed in accordance with these instructions so as not to void our warranty.

Open the boiler crate and check the contents. In the event of shortage or damage, notify the transportation company immediately.

Locating the boiler

The compact construction of the electric-hydronic boiler permits installation in an alcove, storeroom or other small area. The location chosen should have convenient electrical service.

Allow sufficient clearance above and below the boiler cabinet to permit installation of supply and return piping. A minimum of 6 inches is required at the top of the boiler for installation and accessories. A clearance of 10 inches is required on the right hand side for removal of the elements.

Expansion tank sizing

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

If a Fill-Trol system is used, refer to Table 1 for proper sizing. If Fill-Trol action is not desired, size the expansion tank according to the water volume of the system. If a standard closed expansion tank (without a diaphragm) is used, the air vent tapping on the boiler casting makes a convenient point of connection. The No. 109 Fill-Trol is furnished as standard equipment.

Table 1	Expansion tank sizing (Tank sizing based on 200 °F
	average system temperature.)
Boiler	Standard Fill-Trol tank	Additional Ex-Trol tank
model	(for series loop or one-pipe system	(for cast-iron radiators or
number	with convector baseboard)	cast-iron baseboard)
PER-15	No. 109	No. 15
PER-20	No. 109	No. 15
PER-25	No. 109	No. 15
Note: Gravity systems converted to a forced hot water system usually require
additional compression tank capacity.

Mounting the boiler

Normally, the boiler will be installed against a frame or masonry wall. If the wall surface is rough or uneven, it may be necessary to mount plywood on the wall, then mount the boiler on the plywood. Refer to “Dimensions”on page 12 and “Ratings” on page 13, and note the boiler weight. Be sure that the wall structure will support the boiler and its piping.

The 9/16" top mounting holes and 5/16" lower mounting holes are on 16-inch centers to permit installation on studs in standard wall construction. The use of ¼" x 2½" lag screws is recommended for mounting the boiler. The head diameters of the top two screws must not exceed 9/16".

1.Locate the top mounting holes so that the boiler will be level. Install the screws so that the heads protrude ¾" from the wall.

2.Raise the boiler to mounting position by placing a board across the bottom of the boiler or by grasping the lower left and right inside corners. Do not attempt to lift the boiler by grasping the bottom jacket cross tie.

3.Place the top brackets over the lag screws and then install screws through the lower mounting holes. The top screws can now be tightened.

Hydrostatic pressure test

Pressure test boiler before attaching piping or electrical supply.

1.Install air vent in tapping on top of boiler.

2.Plug remaining tappings, including relief valve opening.

3.Connect water supply. Fill boiler and purge all air. For more than 10 minutes, pressure-test at 1½ times maximum working pressure.

Do not leave boiler unattended. Cold water fill could expand and cause excess pressure, resulting in severe personal injury, death or substantial property damage.

4.Check for maintained gauge pressure. Visually check for leaks if gauge pressure drops.

5.Drain boiler and repair leaks if found.

Leaks must be repaired at once. Failure to do so can damage boiler, resulting in substantial property damage.

6.Retest boiler after repairing leaks.

7.Remove testing plugs and air vent.

Do not use petroleum-based cleaning or sealing compounds in boiler system. Severe damage to boiler will result, causing substantial property damage.

Part number 550-141-396/0801 3