Plastic caps and plugs for HVAC heat exchanger open ports are available. According to the manufacturer, for efficiency, heat exchanger tubing requires protection from dirt, moisture, and debris, from manufacturing through installation in a final unit. By using stock caps or plugs, contamination is easily prevented. Available caps and plugs include short caps, EPDM caps, long caps, end caps, tear caps, side pull plugs, and T-plugs.
StockCap, 123 Manufacturers Dr., Arnold, MO 63010; 800-827-2277; www.stockcap.com