WorksheetsPPT 3 - Central heating systems installed in domestic dwellings
Total questions: 25
Worksheet time: 13mins
What is the function of the heat sink in a solid fuels boiler system?
To increase the temperature
To dissipate heat and prevent overheating
To control the flow of fuel
To generate electricity
What is the heat sink generally composed of in a solid fuels boiler system?
A fan and a filter
A radiator with two lock-shield valves
An electric coil
A water pump
How is the boiler thermostat on a solid fuel boiler typically controlled?
By an electronic control panel
By a remote control
By an air damper
By a digital thermostat
What is one advantage of the two-pipe semi-gravity system with a heat sink?
Restricted heat control
Compliant with Building Regulations part L
Only used on open vented systems
Overheating possible
Which components are installed to control fully pumped systems?
Cylinder thermostat, room thermostat, and programmer
Fan, compressor, and radiator
Timer, switch, and valve
Heater, cooler, and regulator
What type of valves can be used in fully pumped systems?
One-way valve or two-way valve
Two zone valves or a three-port mid-position valve
Pressure valve or release valve
Check valve or gate valve
What fuels can be used for boilers in fully pumped systems?
Coal, wood, or electricity
Natural gas, LPG, or oil
Solar, wind, or hydro
Diesel, kerosene, or propane
What type of system is generally used in pumped central heating to assist heat-up time?
Single-pipe system
Two-pipe system
Three-pipe system
Four-pipe system
What does the three-port mid-position valve control in a Y plan system?
The flow of water to the hot water cylinder and heating circuit
The flow of electricity to the heating circuit
The flow of air to the ventilation system
The flow of gas to the boiler
How does the automatic bypass valve benefit the system?
It increases the water temperature
It prevents lock out and prolongs the circulator life
It decreases the system pressure
It controls the room thermostat
When does the bypass open in the Y plan system?
When the system pressure decreases
When circuits close down due to reaching temperature
When the room thermostat is turned off
When the boiler is turned off
What is the primary function of the zone valve in the S plan system?
To heat the water
To act as an isolator, closing off the flow of water
To cool the water
To increase water pressure
What should be done if a property is more than 150m² in the S plan system?
Install a larger boiler
Fit an additional heating zone valve
Increase the water pressure
Add more radiators
Which system allows zoning?
Y plan
S plan
Both Y plan and S plan
Neither Y plan nor S plan
What is the purpose of the locking out system in a boiler?
To increase water pressure
To shut down the boiler if the flow is above 85ºC
To enhance heat production
To reduce noise in the system
What is a major cause of corrosion in a central heating system?
Excessive heat
Aeration
Low water levels
High pressure
What does aeration in a central heating system produce that is often found as black sludge?
Rust
Magnetite
Calcium deposits
Lime scale
What component replaces the feed and expansion cistern in a sealed system?
Detachable filling loop
Sealed expansion vessel
Double check valve
Filling connection
Why is a double check valve installed in a sealed system?
To increase water pressure
To prevent back siphoning of central heating water
To allow air into the system
To replace the expansion vessel
What is the purpose of a detachable filling loop in a sealed system?
To release excess pressure
To fill the system under mains pressure
To drain the system
To replace the double check valve
What is the purpose of a pressure relief valve in a sealed system?
To increase the system pressure
To discharge pressure to a safe location
To connect the filling loop
To reduce water temperature
According to the Water Regulations, what must be done after a sealed system is charged to the correct pressure?
The pressure relief valve must be removed
The filling loop must be disconnected
The system must be drained
The isolation valve must be opened
What happens to the water in a sealed heating system as it heats up?
It decreases in volume.
It remains the same volume.
It increases in volume.
It evaporates completely.
What is the purpose of an expansion vessel in a sealed plumbing system?
To increase water pressure
To allow for water expansion
To heat the water
To filter impurities
Which component in a sealed system is responsible for releasing excess pressure?
Pressure gauge
Programmer
Pressure relief valve
Wiring centre
