Worksheets8202L3HWPPT1Q1NEW
Total questions: 38
Worksheet time: 19mins
Under a centralised system, which type of hot water system uses a 'Combi boiler?
Storage
Instantaneous
Thermal store
Gas storage water system
Which type of hot water system is described as 'Open vented/cistern fed system' under the centralised system?
Storage
Instantaneous
Gas storage water system
Unvented mains fed system
Which of the following is NOT a sub-division of centralised open-vented hot water systems?
The direct system
The indirect system
The double-feed indirect system
The triple-feed, self-venting system
What type of centralised open-vented system uses a single feed and is self-venting?
The direct system
The indirect system
The double-feed indirect system
The single-feed, self-venting indirect system
What is a typical heat source for the direct open-vented hot water storage system?
Gas boiler
Electric immersion element
Solar panels
Heat pump
What is the single-feed indirect hot water storage cylinder also known as?
A) Dualmatic
B) Primatic
C) Prismatic
D) Dynamic
What is the function of the heat exchanger in the indirect hot water storage system?
A) To cool the primary water
B) To heat the secondary water
C) To store excess water
D) To generate electricity
What is the function of the 22mm vent pipe in the single feed indirect system?
To supply water to the boiler
To provide ventilation and prevent vacuum formation
To circulate hot water through the system
To drain the system when maintenance is required
In a double feed indirect system, what is the purpose of the 15mm cold feed to the primary system?
To supply cold water to the hot water outlets
To fill and maintain the water level in the central heating system
To provide a direct water supply to the boiler
To act as a vent for the central heating system
What is the role of the 22mm draw-off to the bath in the single feed indirect system?
To supply hot water to the bath
To supply cold water to the bath
To drain the bath water into the system
To circulate water between the bath and the boiler
Which component ensures the circulation of hot water in the double feed indirect system?
22mm vent pipe
22mm primary flow and return from the coil in the cylinder
15mm cold feed to the primary system
Circulating pump
What is the function of the internal coil in an indirect open vented hot water system?
To store extra water for future use
To act as a backup power source
To act as the heat exchanger to heat the stored water
To cool down the water before it is used
When is the backup electric immersion often used in an indirect open vented system?
When the water pressure is too high
When the heat source is off or when the system is being serviced
During the regular heating cycle
When the water temperature exceeds a certain limit
What type of hot water supply system uses a coil for indirect double feed?
Open vented cylinder with no coil
Open vented cylinder with chamber indirect single feed
Open vented cylinder with coil indirect double feed
Open vented cylinder with direct immersion
Which open vented cylinder type is characterized by having no coil and using direct immersion?
Open vented cylinder with coil indirect double feed
Open vented cylinder with chamber indirect single feed
Open vented cylinder with no coil direct immersion
Open vented cylinder with indirect double feed
What distinguishes a chamber indirect single feed open vented cylinder from the other types shown?
It uses a coil for indirect heating.
It has no coil and uses direct immersion.
The air bubble
It uses direct double feed.
What is the normal size of the primary feed and return pipework in a hot water supply system?
15mm
22mm
28mm
35mm
What size of pipework is required if the hot water supply system is from a solid fuel boiler?
15mm
22mm
28mm
35mm
According to part L, what is the heat-up time now for a hot water supply system?
10 minutes
15 minutes
25 minutes
30 minutes
How quickly will high heat recovery cylinders heat up?
5 minutes
10 minutes
15 minutes
25 minutes
Where should the cylinder control thermostat be positioned on the cylinder?
At the top of the cylinder
Between 1/4 and 1/3 from the base of the cylinder
In the middle of the cylinder
Between 1/2 and 2/3 from the base of the cylinder
What is an unvented hot water storage system supplied with?
Water from a cold water storage cistern
Water above atmospheric pressure
Water from an open vent pipe
Water from an external expansion vessel
What does an unvented hot water system NOT require?
A cold water storage cistern
A booster pump
A water undertaker’s mains supply
An expansion bubble within the storage cylinder
How does an unvented hot water system differ from open-vented types?
It has an open vent pipe to atmosphere
It operates below atmospheric pressure
It does not have an open vent pipe to atmosphere
It requires a cold water storage cistern
How is the expansion of water due to heating accommodated in an unvented hot water system?
By a cold water storage cistern
By a booster pump
By an external expansion vessel or an expansion bubble within the storage cylinder
By an open vent pipe to atmosphere
What is the maximum temperature that the water within the storage cylinder of an unvented hot water unit should not exceed?
90°C
100°C
110°C
120°C
What is the purpose of the mechanical safety devices in an unvented hot water system?
To increase the pressure of the water
To heat the water
To control the expansion of water and ensure safe temperature limits
To purify the water
What does the diagram in the image represent?
A heating system layout
A pipework layout for an unvented hot water unit
A cooling system schematic
A water purification system diagram
What is the purpose of the check valve in the UHWSS installation pipework layout?
To regulate the water temperature
To prevent backflow of water
To filter debris from the water
To reduce water pressure
Where is the temperature relief valve located in the UHWSS installation pipework layout?
Near the sink
Next to the system boiler
Attached to the expansion vessel
On the cylinder
What is the function of the pressure reducing valve in the UHWSS installation pipework layout?
To increase water pressure
To maintain a constant water temperature
To reduce water pressure
To prevent water from freezing
What are gas-fired instantaneous multi-point hot water heaters designed to do?
Heat the water over a prolonged period.
Supply multiple outlets
Store hot water for future use.
Operate as central heating systems.
What additional capability do gas- or oil-fired combination boilers have besides operating as instantaneous hot water heaters?
They can cool water instantaneously.
They have a central heating capability.
They function as water softeners.
They are used for water filtration.
What is another term for thermal stores as mentioned in the text?
Water-jacketed tube heaters.
Instantaneous storage units.
Central heating boilers.
Multi-point water heaters.
What principle does the multi-point heater work on to create a pressure differential across the gas valve?
Pascal's principle
Archimedes' principle
Bernoulli's principle
Boyle's law
What happens to the hot water delivery in a multi-point heater when the tap is running?
The hot water delivery stops.
The hot water is delivered as long as the tap is running.
The hot water delivery is limited by the storage capacity.
The hot water is delivered after a delay.
Is there a limit to the amount of hot water that can be delivered by a multi-point heater?
Yes, it is limited by the tank size.
Yes, it is limited by the heating element capacity.
Yes, it is limited to the flow rate
Yes, it is limited by the pressure differential valve.
Does a multi-point heater have a storage capacity for hot water?
Yes, it has a small storage tank.
Yes, it has a large storage tank.
No, there is no storage capacity.
Yes, but it is only for cold water.
