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AIR CONDITIONING & HEAT PUMP SYSTEMS
BACKDRAFTING HEATING EQUIPMENT
BACKUP HEAT for HEAT PUMPS
BANGING HEATING PIPES RADIATORS
BLOWER FAN OPERATION & TESTING
BOOKSTORE - InspectAPedia
BTU USAGE MONITORS
CARBON MONOXIDE - CO
CIRCULATOR PUMPS & RELAYS
DIAGNOSTIC GUIDES A/C / HEAT PUMP
DIAGNOSE & FIX HEATING PROBLEMS-BOILER
DIAGNOSE & FIX HEATING PROBLEMS-FURNACE
DIRECT VENTS / SIDE WALL VENTS
DRAFT REGULATORS, DAMPERS, BOOSTERS
DUCT SYSTEM & DUCT DEFECTS
ELECTRIC MOTOR DIAGNOSTIC GUIDE
FAN, AIR HANDLER BLOWER UNIT
FLOODED HEATING EQUIPMENT REPAIR
FLUE SIZE SPECIFICATIONS
GAS BURNER Flame & Noise Defects
GAS PIPING, VALVES, CONTROLS
GEOTHERMAL HEATING SYSTEMS
HEAT PUMPS, DIAGNOSIS, REPAIR
HEATING COST SAVINGS METHODS
HEATING OIL PIPING TROUBLES
HEATING OIL TANKS
HEATING SYSTEM NOISES
HEATING SYSTEM TYPES
GAS LP & NATURAL GAS SAFETY HAZARDS
MANUALS & PARTS GUIDES - HVAC
MIXING / ANTI-SCALD VALVES
MOTOR OVERLOAD RESET SWITCH
NOISE, HEATING SYSTEMS
ODORS FROM HEATING SYSTEMS
OIL FILTERS on HEATING EQUIPMENT
OIL FILL PIPE LEAKS
OIL SPILL CLEANUP / PREVENTION
PLASTIC Plexvent / Ultravent RECALL
PUFFBACKS, OIL BURNER
RELIEF VALVE LEAKS
Reset Switch - Heater Primary Control
RESET SWITCH - ELECTRIC MOTOR
Reset Switch - Stack Relays
SAFETY, HEATING INSPECTION
SAFETY RECALLS CHIMNEYS VENTS HEATERS
SOLAR HEATING SYSTEM DESIGNS
SOOT on OIL FIRED HEATING EQUIPMENT
STEAM HEATING SYSTEMS
THERMOSTATS, HEATING / COOLING
VIDEO GUIDES: Heating System Videos
WINTERIZE A BUILDING
WOOD, COAL STOVES & FIREPLACES
WOOD STOVE SAFETY
ZONE VALVES, HEATING
Variable speed heating zone circulators: this article describes brands & models of forced hot water heating system circulator pumps whose motor speed or circulating speed can be set to varying rates. We describe both older obsolete variable speed circulator pumps and modern currently-available models including manufacturer brand, model, and circulator pump sources.
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Variable speed heating zone circulators provide an additional level of heating zone control and can be used to solve heating problems amenable to either an increase in circulating water speed (get more heat in a zone) or a decrease in heating zone circulator speed (less heat or continuous, more even heat).
Older Variable Speed Heating Circulator Pumps
At left is a Bell & Gossett UpStart hot water heating zone circulator pump produced - a B&G product no longer distributed. This circulator pump included a variable-speed circulator motor (see that gold knob on the electrical box atop the motor?).
This hot water heating zone circulator used a four-speed motor whose output rate could be set by the consumer or heating service technician.
By changing the circulator motor speed on this pump or on the next model shown below, we could slow or speed the flow rate of hot water through the zone managed by this circulator. The result: this control provided another way to balance heat flow among multiple zones (and circulators) in a building.
This circulator, the Bell & Gossett SLC-25 Upstart Circulator was sold during the 1980's and is not currently available. But B&G offered similar replacements (such as the NRF-22).
At below is a newer but also obsolete product, the B&G NRF-VS variable speed circulator is shown.
Currently-Available Variable-Speed Heating Circulator Pumps & Controls: Taco BumbleBee & Grundfos Alpha Series & MixiMiser™
Other variable speed circulators include the Taco BumbleBee High-Efficiency Variable-Speed Circulator HEC-2 and Variable speed circulators from Grundfos.
Quoting from the company's product literature:
The Taco Bumble Bee (model HEC-2) represents the very latest in variable speed wet rotor circulator technology. Its high efficiency ECM motor uses up to 85% less electricity than a standard circulator, and its out-of-the-box settings and 360 ̊ swivel flange makes it a breeze to install. Most importantly, the Bumble Bee’s Delta-T variable speed technology maximizes the overall efficiency of your heating system. - Taco Catalog q#100-101 retrieved 1/24/2014 [on file] see References at the end of this article
Alpha Series pumps by Grundfos also provide variable speed hydronic heating water circulation control. Quoting [with minor adaptations] from product literature from Grundfos, including the UPS15-58FC and the Grundfos Alpha series.
If the heating boiler itself if does not turn on in a response to a call for heat see NO HEAT - BOILER.
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