150589 Central Heating Systems – Worksheet MCQs (Grade 14)

The primary purpose of domestic central heating is to?

• Provide thermal comfort by balancing physical and personal factors

• Maintain constant humidity only

• Increase air velocity in rooms

• Dry out building fabric

Which pair correctly lists one physical and one personal factor in thermal comfort?

• Humidity & clothing

• Air velocity & stress unrelated

• Metabolism & open vent

• Condensation & dew point

‘Full central heating’ is best defined as?

• Simultaneous heating of all spaces to specified temperatures based on calculated heat losses

• Heating some spaces below recommended temperatures

• Heating only the living areas

• Background heating to reduce condensation only

Which statement about one-pipe vs two-pipe systems is true?

• Two-pipe systems deliver similar temperatures to all radiators via separate flow/return

• One-pipe systems are more efficient and modern

• Two-pipe systems rely on gravity only

• One-pipe systems eliminate temperature drop across radiators

Before first fill, which check is essential?

• All open ends capped/valves isolated and drain valves closed

• Pump set to speed 3

• TRVs removed

• Cylinder thermostat set to 60°C

In open-vented systems, provisional fill level should be set in:

• The feed & expansion cistern

• The cold water storage cistern

• The expansion vessel

• The boiler heat exchanger

On sealed systems, initial filling should be done to about?

• 1 bar cold pressure

• 3 bar cold pressure

• 0.2 bar cold pressure

• 2.5 bar cold pressure

During staged filling of sealed systems, you should?

• Turn off the filling loop between venting stages to prevent rapid overfilling

• Leave the filling loop open until all radiators are vented

• Fill via the F&E cistern

• Open PRV continuously

BS EN 14336 requires heating systems be pressure tested to:

• At least 30% above working pressure for a minimum of 2 hours

• Exactly working pressure for 30 minutes

• Twice working pressure for 10 minutes

• 1 bar for 1 hour

Prior to hydraulic testing you should:

• Remove vulnerable items like the pump and ensure vents at high points are closed

• Open PRV to atmosphere

• Disconnect cylinder coil

• Fill with glycol