WorksheetsPPT 11 - Testing and filling the central heating system
Total questions: 25
Worksheet time: 13mins
What is the general rule for determining the system test pressure?
1.5 x the working pressure
2 x the working pressure
1 x the working pressure
0.5 x the working pressure
What is the recommended test pressure for a sealed system with an operating pressure of 2 bar?
3 bar
2 bar
1 bar
0.8 bar
According to BS14336, what is the recommended test duration?
Two hours
One hour
Three hours
Four hours
What is the first step in the procedure for hydraulic pressure testing?
Release air from high points systematically.
Raise the pressure to test pressure and seal.
'Walk' the system continuously checking for leaks.
Check that stop valves are not letting.
What is the purpose of releasing air from high points in the system during hydraulic pressure testing?
To increase the water pressure.
To systematically check for leaks.
To ensure the system is full of water.
To prevent air pockets and ensure proper pressure.
What is the purpose of removing the circulator when cold flushing a system?
To increase water pressure
To prevent debris from getting caught in the impellor
To add more coolant
To reduce noise levels
What can flushing remove from a system to prevent problems?
Excess water
Excess flux, wire wool, and loose solder
Air bubbles
Rust
What is the purpose of cold flushing in plumbing systems?
To remove excess jointing compounds
To check for leakage
To remove debris left over from installation
To separate oils from components
What does hot flushing remove from plumbing systems?
Water
Debris
Jointing compounds, flux residues, and oils
Air bubbles
Why is it important to conduct a hot flush after installation?
To fill the system with water
To check for leaks
To separate unwanted substances from the pipework
To cool down the system
What is the process of releasing trapped air or hydrogen from the top of a radiator called?
Venting
Bleeding
Aeration
Corrosion
What can create a cool/cold area at the top of a radiator?
Trapped air
Trapped hydrogen
Magnetite formation
Water loss
What effect does magnetite formation have on a radiator?
It creates a warm area at the top
It creates a cool/cold area at the bottom
It increases water flow
It prevents corrosion
What should be done when system water is released during the bleeding process?
Open the bleed valve wider
Tighten the bleed valve
Turn off the central heating system
Remove the dust sheet
What is the first step in the safe isolation procedure before working on an electrical component?
Remove the fuse
Lock off the fuse holder
Switch off the fused spur
Place a sign indicating work
What is the purpose of the lock shield valve in a plumbing system?
To increase water pressure
To balance the system when commissioned
To filter impurities from water
To reduce noise in the pipes
What happens if a plumbing system is left unbalanced?
The radiators will overheat
The radiators will not warm up uniformly
The water flow will stop completely
The system will become more efficient
What is the required temperature difference between the flow and return pipework in a balanced system?
5°C
10-12°C
15°C
20°C
What is the main factor that causes some radiators to heat up more quickly than others in a plumbing system?
The size of the radiator
The color of the radiator
The resistance offered by the pipework, fittings, and bends
The material of the radiator
What is the term used for the radiator that heats up last in a plumbing system?
Primary radiator
Index radiator
Final radiator
Lead radiator
Why is it important to identify the index radiator in a plumbing system?
It is the largest radiator
It has the least resistance
It has the greatest resistance and heats up last
It is the most expensive radiator
How do you calculate the number of turns needed to balance a system with radiators?
Multiply the number of radiators by the number of turns
Divide the number of turns by the number of radiators
Divide the number of turns by the number of radiators plus one
Add the number of turns to the number of radiators
How can the temperature difference in the system be measured?
By using a ruler
By using clip-on thermometers or digitally
By using a stopwatch
By using a pressure gauge
Where does the water that fills the radiator come from in a gravity-fed system?
The F&E cistern
The main water supply
The boiler
The water heater
What might be necessary if a radiator in a sealed system is filled under system pressure?
Repressurising the boiler
Draining the system
Replacing the radiator
Increasing the water temperature
