Boiler system circulation pumps come with various options depending on the application for standard fixed speed, multi speed, high efficiency variable and proportional curve pumps. Armstrong, Grundfos, Bell and Gossett, Wilo, Taco to name a few. These pumps are used in main boiler primary loop circulation, secondary loop or zone circulation and injection mixing pumps. Proper pump selection and sizing is critical if the hydronic system is to function efficiently. Newer pumps using variable speed technology offer even greater efficiency in that they can use up to 20% less electrical power. Variable or proportional curve pumps are highly recommended in those applications where flow rates are ever changing. For example, in those zone utilizing zone valves or actuators to initiate flow and a call for heat. Deadheading a high efficiency variable or proportional curve pump is less of a concern as they are capable of adjusting output volume.
Common service issues could include seized wet rotor cartridges or lack of boiler system pressure resulting in poor pump performance and reduced circulation. Fluid condition is more of a concern in systems using high efficiency pumps as metallic oxides(magnetite) or particulate matter can shorten the service life. Most older coupled circulators and wet rotor boiler pumps require a minimum system static pressure around 8-10 psi to function efficiently. Boiler system pressure feed regulators or an Calefactio GMP system feeder for the average residential boiler system, normally maintain a minimum pressure in the 12 to 14 psi range if properly adjusted. These devices, if properly installed and set up will maintain the desired cold fill pressure the system will require to flow and operate efficiently.
We service, repair and maintain all brands of boiler pumps as part of our boiler system service and repair.
Alberta General Plumbing