CENWAT System Controls and Zoning

Question 1

What is the primary function of a thermostatic radiator valve (TRV)?

Accepted Answer

To control water flow through a radiator based on room air temperature

Answer

To regulate boiler flow temperature

Answer

To measure system pressure at the radiator

Answer

To control pump speed

Question 2

Why must a TRV not be fitted to the radiator in the room containing the room thermostat?

Accepted Answer

Both controls would compete to regulate temperature, causing short-cycling and inefficiency

Answer

TRVs are too large for that room

Answer

The room thermostat requires maximum heat flow at all times

Answer

TRVs cannot be fitted near electrical devices

Question 3

Under Building Regulations Part L, at what minimum floor area does a new domestic heating system require at least two independently controlled temperature zones?

Accepted Answer

150m²

Answer

100m²

Answer

200m²

Answer

250m²

Question 4

Why is an automatic bypass valve (ABV) essential in a system where TRVs are fitted throughout?

Accepted Answer

To prevent pump cavitation and boiler overheating when all TRVs are closed

Answer

To allow air to escape from the system

Answer

To increase flow rate to distant radiators

Answer

To reduce the amount of inhibitor required

Question 5

On a standard TRV head calibrated 1–5 with a frost symbol (*), what room temperature does setting 3 approximately represent?

Accepted Answer

20°C

Answer

15°C

Answer

18°C

Answer

25°C

Question 6

What is the recommended temperature range for setting a room thermostat in a domestic property?

Accepted Answer

18–21°C

Answer

15–18°C

Answer

22–25°C

Answer

25–28°C

Question 7

What is the purpose of a lockshield valve on a radiator, and who should adjust it?

Accepted Answer

To balance system flow during commissioning; adjusted by the installer using a tool

Answer

To allow the homeowner to fine-tune room temperature daily

Answer

To isolate the radiator in an emergency; adjusted by any competent person

Answer

To control heating circuit pressure; adjusted automatically