A schematic, very similar to the one below, appears in a manufacturer’s installation manual. It represents the manufacturer’s recommendation for installing a two-zone system. Can you identify at least five things that could be changed to improve this system?

An installer has piped a multiple boiler system to supply two loads.

An installer plans to replace an outdoor wood-fired furnace with a new cordwood-gasification boiler with a rated output of 150,000 Btu/hr. The outdoor furnace is located about 100 ft. from the indoor mechanical room where the 1-in. PEX insulated underground piping joins the thermal storage tank. The installer plans to use the existing underground piping.

An installer wants to achieve hydraulic separation between three zone circulators. He also wants to have the same supply water temperature to each zone, so he pipes up what he calls a “modified primary/secondary system.”

A designer needs to connect an indirect water heater to a multiple boiler system. He selects a hydraulic separator and connects the piping of the indirect water heater on the same side as the boilers.

A heating professional is asked to retrofit a biomass boiler to an existing distribution system consisting of older cast-iron radiators, iron piping and an oil-fired boiler.

A multiple boiler system using sectional cast-iron boilers has been configured to supply two loads.

An installer is asked to provide a relatively simple single-zone, slab-type floor heating system supplied by a geothermal water-to-water heat pump. He’s heard that a hydraulic separator is a good component in such systems.

An installer uses an unpressurized thermal storage tank for drainback protection of a solar thermal system, and carefully slopes all the collectors and collector array piping for 1/4 in. per ft. drop.

An engineer is planning underground insulated piping for a small district heating system, which receives heat from a central boiler plant and distributes it to three separate buildings. He is planning what he calls a “primary/secondary” piping system.