Piping & Pumps
Pressure relief valves are rated in...
PSI and BTU
If you get water out of the bottom of a Bladder Expansion Tank (at the pressure port on the bottom), what should you do?
Replace the tank
What is the TH/TR Terminal used for on a Zone Valve?
Connection Point
What is the definition of a BTU? (not British thermal unit)
amount of heat to raise 1lb of water 1 degree F.
Where should you install the Back-Up Aqua-Stat?
Outlet or Supply out of the boiler
What boiler component controls the make-up water supply pressure?
Pressure Reducing Valve
What is the purpose of the vent tee on a Finned-tube heat emitter?
To help remove air from the system.
When checking voltage across a set of contacts (switch) and the voltage reads 120v, the contact is what? (i.e. bad, closed, shorted etc)
Open
What is the Low Water Cut-Off?
Shuts down the system if water gets too low
What system pressure should most residential boilers operate at? (cold start)
12 PSI
All safeties are wired in ______________on a boiler system
Series
List three heat emitters
Base Board, Fan Coil, In floor
What does adding glycol to a hydronic system do to the transfer of heat?
reduces it.
Name two types of circulator pumps (not brands)
Wet Rotor, Three piece, ECM, Two piece
Name 3 safety controls added to the boiler externally.
Low water cutoff, Flow Switch, Back up Aquastat
A back up aqua stat or secondary limit is designed to?
Disable the burner/boiler circuit if the boiler gets too hot
A boiler relief valve is typically set to relieve at what pressure?
30 PSI
List 3 advantages to using a Boiler System instead of a Forced Air System
Quiet; cleaner; even heat; snow melt; less invasive; DHW; In floor heat
What opens the contacts on the Back-Up Aqua-Stat?
Too high of water (Supply) temperature
What is the purpose of the lever on the zone valve?
Used to manually open the valve
What does a Back Flow Preventer do?
Prevents water from going backwards.
How many BTU’s are there in 4ft of 3/4” 2x2 copper fin tube @180 degree boiler temperature
2400 BTU
How do steel fire-tube boiler heat exchangers work?
Water surrounds a group of steel tubes through which hot combustion gases pass
If a circulator pump speed in a zone is too high/fast, what effect does that have on the temperature? Explain.
Room remains cold; it has less time to release the heat from the system.
What is the purpose of using a Primary Loop on a 90% efficient boiler?
To allow the boiler to have constant water supply.