What Are Common Mistakes in Installing Drainback Systems?

Incorrect Sizing

Incorrect sizing is a common mistake in installing drainback systems. If the collector is oversized relative to the storage tank, it can lead to reduced system performance and increased risk of freezing. As a rule of thumb, the collector area should be sized to match 80-90% of the storage tank’s capacity. For example, if the storage tank is 100 gallons, the collector should be sized for 80-90 gallons of daily collection. Oversizing the collector can lead to increased pressure drop in the system, making it more difficult to drain back.

Inadequate Slope and Drainback Line Issues

An inadequate slope in the drainback line can cause the system to drain back slowly, leading to reduced system performance. The recommended slope for drainback lines is 1/4 inch per foot, with a minimum slope of 1/8 inch per foot. If the slope is too shallow, it can lead to clogging or freezing of the drainback line. Additionally, if the drainback line is too small, it can cause backpressure in the system, making it more difficult for the system to drain back.

Drainback Line Clogs and Obstructions

Clogs and obstructions in the drainback line can cause significant problems in drainback systems. Common culprits include debris, sediment, and scale buildup. To prevent clogs, it’s recommended to install a magnetic drain trap or a sediment filter on the drainback line. Regular maintenance, such as cleaning the drainback line and checking for blockages, can also help prevent clogs and ensure the system operates efficiently.