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

The designer’s intent was to supply a low-temperature floor-heating zone, as well as a higher-temperature baseboard zone and air handler, from a thermal storage tank heated by a pellet-fueled boiler.

An installer sets up a zoned distribution system. To keep it simple, he uses the same size piping for the headers and all the distribution circuits. The heat source is a low-mass copper tube boiler with high flow resistance.

An installer pipes up a system using a conventional gas-fired boiler to supply heat to a low-temperature radiant panel system.

Due to the high price of fuel oil, a contractor is hired by a building owner to install a wood-gasification boiler to supplement the oil boiler. The building’s distribution system consists of a three-zoned air handler with hot water coils.

The three photos, provided by a friend of the industry, are all from the same hydronic heating installation.

A homeowner wants to use a wood-gasification boiler as his primary source of space heating. He also wants a propane-fueled boiler to automatically come on for backup should he decide not to tend the fire, or if he is away. The owner has read that a generously sized thermal storage tank is necessary to allow a gasification boiler to operate at consistent high efficiency.

A hydronic system is to supply four panel radiators, each with its own thermostatic radiator valve, and an indirect water heater from a gas-fired sectional cast-iron boiler. The system is designed using primary/secondary piping.

The hydronic system shown above was created to connect three gas-fired, cast-iron boilers to a low-temperature distribution system that supplies 12,000 ft. of 3/4 in. PEX tubing embedded in the floor slab.The installer spends several frustrating hours attempting to get the air out of the system. He finally gets it purged to the point that the distribution circulator is at least moving some water through the floor-heating circuits.

Joe Wrenchturner gets a call to install solar water heating for a longtime customer. He buys some flat-plate collectors through an online source and decides to assemble the remainder of the system using hardware he installs for other hydronic systems.