1. new homes
   existing homes
2. new commercial properties

New homes do not typically have these systems installed, but existing homes may.

1. gravity system
   hydronic system
2. both answers

The gravity system and the hydronic system are both hot water systems.

1. gas, coal or wood
   gas, oil or electric
2. wood, gas or oil

Gas, oil or electric are use to power hot water heating systems.

1. 120
   150
2. 180

Gravity systems heat water to 180 degrees Fahrenheit.

1. motor-driven circulating pump
   fan
2. neither answer

A motor-driven circulating pump is used to move water. Because of the pump, the water moves faster than with a gravity system and less heat is lost in the process.

1. broken pump
   broken fan
2. incorrect slope

The incorrect slope of the pipes or radiators is indicated by hammering noises and a failure to heat.

1. half full
   three quarter full
2. full

The boiler should be kept half full.

1. boiler malfunction
   insufficient heating
2. hammering noise

Too little water may cause insufficient heating.

1. automatic filling system
   manual filling system
2. neither answer

An automatic filling system maintains the boiler at the proper water level.

1. by feel
   by weight
2. by indicator

If the tank feels hot all over, it has too much water and must be drained to allow room for air.

1. none
   one to two gallons
2. two to three gallons

Do not refill the expansion tank; it will fill up with normal system operation.

1. one quarter open
   half open
2. fully open

The valve should be opened all the way.

1. pump
   fan
2. blower

A circulator is a pump that pushes hot water towards the home's radiators.

1. every month
   every year
2. every two years

Flush the systems annually.

1. drain the system
   turn off the boiler
2. let the water run

If pipes are in danger of freezing, drain the hot water system.

1. vents need adjustment
   boiler needs service
2. radiator malfunction

The vents may need adjustment. The vents farthest from the boiler should be opened the most.

1. damaged seal
   damages coupler
2. stem packing deterioration

The seal may be damaged. A professional is required for this type of repair.

1. The water will flow back to the boiler.
   The water in radiators stay at a steady level.
2. Neither answer is correct.

As the system cools, the water will flow out of the radiators back to the boiler.

1. attic
   basement
2. close to the boiler

Older systems may house the expansion tank in the attic, while newer systems hang the tank from the basement ceiling .

1. toward the boiler
   away from the boiler
2. neither answer

The pipes must slope back toward the boiler.