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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
How to diagnose & fix trapped air in heating systems causing cold baseboards, convectors or radiators: beginning right here we describe six different causes & cures for cold radiators and baseboards due to air trapped in the heating system. These diagnostic routines are described in the order they should be tried.
We start by confirming that we think the problem is that air trapped in the hydronic (hot water) heating system piping, boiler, radiators, baseboards or convectors is preventing heat from being delivered to the building.
After cofirming that the building is calling for heat but some areas are not getting it, we explain how to find where the trapped air is actually located and we give a series of steps to fix the trouble, starting with a simple simple procedure for bleeding trapped air at registers or baseboards. If necessary there are additional methods used to remove air from air-bound hot water heating systems using two different service procedures to force air out of airbound pipes in a hot water heating system.
This article series provides a detailed guide fixing no-heat calls in which the heating boiler and circulator are running but heat is not being delivered to one or more building areas.
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How to Recognize & Fix Problems Caused by Air In Hot Water Heating System Pipes, Radiators, Baseboards
Check hot water baseboards, radiators, or heating convectors: if some of these heating devices are hot and others cold, are they all on the same heating zone? Feel the hot water piping leaving the heating boiler - it should be hot when the boiler is running and the thermostat is calling for heat.
If the building has multiple heating zones each zone will be controlled by its own thermostat and each heating zone will either have its own hot water circulator pump (controlled by a thermostat and pump relay switch), or each hot water heating zone will have its own thermostat and a zone valve that opens to let a common circulator pump send hot water through that individual heating zone. Are all of the thermostats turned up high enough to call for heat in each heating zone?
If some heating baseboards or radiators are hot and others cold and we're sure that they're on the same heating zone, then the system is probably air-blocked.
Watch out: it is not obvious to people not expert in hot water heating systems, but the circulator pump on a typical hot water (hydronic) heating system does not have enough oomph to push a bolus of trapped air around through the heating system pipes. If more than small bubbles of air remain trapped inside the heating piping the circulator may spin without actually pushing hot water through the system. By purging the trapped air we get the hot water circulating again.
List of Diagnostic Articles Addressing Problems with Air in Heating Systems
Our discussion of radiators or baseboards that do not get hot when they should includes these articles on how to get rid of air in hot water or hydronic heating systems in order to prevent or cure air-bound heating systems (sections of baseboard or radiators that don't get hot):
This article series answers nearly all questions about diagnosis & repair of residential & light commercial central heating systems.
If your heating system is not working properly, see NO HEAT - BOILER for forced hot water or steam heat.
See NO HEAT - FURNACE if your heat is by forced warm air.
If you don't know what kind of heat your building uses, we explain how to figure out the answer at HEATING SYSTEM TYPES.
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