WorksheetsHot Water System Quiz Quiz 1
Total questions: 20
Worksheet time: 10mins
You are called to a customer’s property and notice water discharging from the open vent pipe into the cold water storage cistern. What is the most likely cause?
Failed float operated valve
System overheating
Blocked cold feed pipe
Incorrect pipe insulation
Where would you normally locate the cylinder thermostat on a domestic hot water cylinder?
At the very top of the cylinder
At the base of the cylinder
One-third of the way up the cylinder
On the primary return pipe
When installing a hot water distribution pipe from a vented cylinder, a minimum vertical rise of 450 mm is required before the vent connection to:
Increase water pressure
Prevent parasitic (one-pipe) circulation
Improve system efficiency
Allow faster heat-up times
Identify the: Immersion heater
Identify the: Blending valve
If the thermostat in an immersion heater fails in the closed position, what is the likely result?
No hot water
Reduced flow rate
Water overheating
Cold water contamination
Identify the: Temperature/Pressure Relief Valve (TPRV)
What is the purpose of a blending valve on a hot water system?
To increase hot water pressure
To reduce stored water temperature
To limit outlet temperature and prevent scalding
To control primary circulation
What is the minimum temperature stored hot water should reach to control legionella?
45 °C
50 °C
55 °C
60 °C
Which type of hot water system operates under mains pressure and does NOT require a cold water storage cistern?
Open vented indirect
Gravity-fed system
Unvented system
Direct cylinder system
What is the minimum pipe size for an open vent pipe on a domestic hot water system?
15 mm
18 mm
22 mm
28 mm
Which of the following components allows for expansion in an unvented hot water system?
Cold feed pipe
Expansion vessel
Open vent pipe
Gate valve
According to Building Regulations Part G, what is the maximum permitted temperature of hot water delivered to a bath?
50 °C
55 °C
48 °C
60 °C
You are working on a customer’s property and identify an unvented hot water cylinder. Who is legally permitted to install or maintain this system?
Any qualified plumber
The property owner
A competent person with unvented certification
The water undertaker
Identify the correct phrase for: Open vent pipe
A pipe designed to regulate water pressure within a sealed hot water system.
A safety pipe that allows expansion, air movement, and discharge in the event of overheating.
A pipe used to drain water from the system during maintenance.
A pipe that supplies cold water directly to the cylinder.
Identify the correct phrase for: Purpose of a Hot Water System
To supply wholesome cold water to appliances throughout a building.
To remove waste water from sanitary appliances.
To heat, store, and distribute hot water safely and efficiently to outlets.
To regulate incoming mains water pressure.
What fault could cause cold water at taps to become warm?
Undersized cold feed pipe
Hot and cold pipes installed too close together
Failed float operated valve
Excessive mains pressure
What is the function of a sacrificial anode in a hot water cylinder?
Improve heat recovery
Prevent limescale
Protect the cylinder from corrosion
Increase system pressure
Which regulation focuses primarily on energy efficiency of hot water systems?
Building Regulations Part G
Building Regulations Part L
Water Supply Regulations
Gas Safety Regulations
You are decommissioning a hot water system for cylinder replacement. Which action must be carried out FIRST?
Drain the system
Isolate the heat source
Remove the cylinder
Open all draw-off points
