9189 Phase 2 Central Heating PP8

What is the main purpose of a pressure relief valve?

• To increase water pressure

• To protect against over-pressurisation of the water

• To decrease water temperature

• To filter water

At what pressure are pressure relief valves usually set?

• 1 bar

• 2 bar

• 3 bar

• 4 bar

What is a sign that the vessel has lost its charge of air?

• The vessel is noisy

• The vessel is hot

• The pressure relief valve opens

• The vessel changes color.

What material should discharge pipework be made of?

• Plastic

• Wood

• Metallic

• Glass

What was the minimum upgrade required for a replacement cylinder with no temperature control?

• Electrical thermostat

• Mechanical cylinder thermostat

• Digital thermostat

• None

What is now recommended instead of gravity systems?

• Electrical systems

• Pumped alternatives

• Solar systems

• Wind systems

What is inside the heat-sensitive head of a TRV?

• A battery

• A cartridge filled with liquid, gas, or wax

• A light bulb

• A fan

For planned radiator replacement, what is recommended?

• Fit TRVs to all radiators

• No action needed

• Replace the boiler

How do low loss headers help in controlling circuits?

• By combining circuits

• By operating circuits independently

• By increasing flow rates

• By reducing pressure.