Weil-McLain 550-141-396/0801 Maintenance, Draining and cleaning, Keeping air vent clean

PER Series 3 Electric-Hydronic Boilers Installation Instructions

Maintenance

This boiler contains fiberglass materials. Use care when handling these materials per instructions on page 11 of this manual. Failure to comply could result in severe personal injury.

Draining and cleaning

Do not drain the boiler during periods of shutdown unless the heating system is exposed to freezing temperatures. At the end of each heating season, open the boiler drain cock just long enough to remove any impurities or sediment that may have settled to the bottom of the boiler.

Keeping air vent clean

Loosen the cap on the Float-Type Automatic Air Vent two turns while the system is being filled with water. Should dirt or scale lodge on the valve seat causing it to leak, remove the vent cap and push the valve core in by hand to permit water to flush the valve seat clean; release the valve core quickly and replace the vent cap. For normal operation and venting, unscrew the vent cap at least two turns.

Checking expansion tank

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 the relief valve opens frequently, check the expansion tank. If the system has a pressurized tank with a rubber diaphragm separating the air cushion from the water (an Ex-Trol or equivalent tank), use a tire pressure gauge to check the air-charging valve on the end of the tank. If water flows, the diaphragm is ruptured or leaking. The tank must be replaced. If no water flows but the air charge has been lost, recharge the tank to 12 pounds per square inch. Periodic air loss from the expansion tank probably means a leaky charging valve.

If the expansion tank is of the standard closed variety, (without a rubber diaphragm) the tank must be partly drained to re-establish an air cushion.

Checking relief valve

Check the relief valve once a year by manually opening the valve and allowing a small quantity of water to flow. Make sure that the valve reseats and does not leak. Replace any defective valve.

Operating temperature and pressure

The maximum recommended low and high limit control settings are 200°F and 220°F, respectively. The relief valve opens at 30 pounds per square inch. The actual operating pressure will range from 12 pounds per square inch when the system is cold to as much as 15 pounds per square inch at maximum operating temperature.

10 Part number 550-141-396/0801