CENWAT Hot Water Systems (Unvented/Vented)

Question 1

What qualification must a plumber hold to install an unvented hot water storage system in the UK?

Accepted Answer

G3 Unvented Hot Water Storage qualification

Answer

ACS domestic core only

Answer

City and Guilds Level 2 Plumbing

Answer

Part P Electrical certification only

Question 2

What is the correct order of safety devices on an unvented hot water cylinder from the water supply inlet?

Accepted Answer

Pressure reducing valve, check valve, expansion vessel, temperature and pressure relief valve

Answer

Expansion vessel, pressure reducing valve, temperature and pressure relief valve

Answer

Temperature and pressure relief valve, expansion vessel, check valve

Answer

Check valve, temperature and pressure relief valve, expansion vessel

Question 3

At what temperature should the temperature and pressure relief valve on an unvented cylinder operate?

Accepted Answer

90-95 degrees C

Answer

75 degrees C

Answer

85 degrees C

Answer

100 degrees C

Question 4

What is the maximum working pressure rating typically specified for an unvented hot water cylinder?

Accepted Answer

10 bar

Answer

3 bar

Answer

6 bar

Answer

16 bar

Question 5

What is the minimum discharge pipe size from the temperature and pressure relief valve to the tundish on an unvented cylinder?

Accepted Answer

15mm

Answer

22mm

Answer

28mm

Answer

35mm

Question 6

In a vented hot water system, what is the purpose of the vent pipe from the top of the hot water cylinder?

Accepted Answer

To provide a path for air and steam to escape safely to atmosphere

Answer

To supply cold water to the cylinder

Answer

To connect to the central heating circuit

Answer

To supply water to the shower pump