Hydraulic piping schemes for pellet boilers FOCUS

We invite readers and buyers to familiarize themselves with the schemes for piping a pellet boiler. Hydraulic circuits are aimed at automating the heating process. Examples of hydraulic piping diagrams for FOCUS boilers will help you to install a boiler room without preliminary design, if the system parameters differ slightly.

Diagram with a four-way valve that controls the central heating circuit¹:

1 - boiler, 2 - burner, 3 - controller, 4 - boiler temperature sensor, 5 - flue gas temperature sensor (for information only), 6 - four-way valve actuator, 7 - circuit pump  mixer, 8 - mixer circuit temperature sensor, 9 - boiler  hot water supply, 10 -  hot water pump, 11 - hot water sensor, 12 - weather temperature sensor, 13 - room panel or standard room thermostat, 14 - return temperature sensor (not required for system operation).

In order to improve the water circulation in the gravity circuit of the boiler, it is necessary to: use large nominal diameters DN of pipes and a four-way valve, avoid a large number of bends and diameter reductions, observe other rules regarding the design of gravity systems, for example, maintaining drops, etc.

If the return sensor is mounted overhead, it should be thermally isolated from the environment and improve thermal contact with the pipe using heat-conducting paste. The preset temperature of the boiler must be set at such a level that the heat output for the mixer circuit can be ensured while simultaneously heating the water returning to the boiler.

Thermal buffer circuit²:

boiler, 2 - burner, 3 - controller, 4 - boiler temperature sensor, 5 - flue gas temperature sensor (for information only), 6 - boiler pump, 7 - heat buffer, 8 - hot water pump, 9 - hot water boiler, 10 - hot water temperature sensor, 11 - mixing valve actuator, 12 - mixer circuit temperature sensor, 13 - mixer pump, 14 - room panel with room thermostat function, 15 - thermostatic three-way valve for return protection, 16 - upper buffer temperature sensor, 17 - lower buffer temperature sensor, 18 - weather temperature sensor, 19 - additional module B.

Circuit with thermal buffer and 5 mixing heating circuits³: