CENWAT Pipework Sizing and Installation 2

Question 1

What type of fitting is NOT permitted for making joints on gas pipework concealed within walls?

Accepted Answer

Compression fittings

Answer

Soldered capillary fittings

Answer

Press-fit fittings with gas-approved seals

Answer

Brazed joints

Question 2

What is the minimum fall required on a condensate pipe from a condensing boiler?

Accepted Answer

A minimum fall of 2.5 degrees, approximately 44mm per metre

Answer

No fall required, it can be installed level

Answer

A minimum fall of 1 degree, approximately 17mm per metre

Answer

A minimum fall of 5 degrees, approximately 87mm per metre

Question 3

What is the purpose of a magnetic system filter installed on the return pipe of a central heating system?

Accepted Answer

To capture magnetic iron oxide sludge (magnetite) from the system water

Answer

To filter the mains water supply

Answer

To regulate the water pressure

Answer

To measure the flow rate

Question 4

What is the minimum insulation thickness required for central heating pipework in unheated areas under Building Regulations Part L?

Accepted Answer

19mm for pipes up to 22mm diameter

Answer

No insulation required

Answer

Equal to the pipe diameter

Answer

25mm for all pipe sizes

Question 5

When sizing radiators for a room, which heat loss calculation method is commonly used in the UK?

Accepted Answer

Using the U-value method considering fabric heat loss and ventilation heat loss

Answer

Simply matching radiator output to room volume

Answer

Estimating 1kW per radiator regardless of room size

Answer

Using only the floor area multiplied by a fixed factor

Question 6

What is the correct procedure for pressure testing a new central heating system before commissioning?

Accepted Answer

Pressurise the system to 1.5 times the maximum working pressure for a minimum test duration, checking for pressure drop

Answer

Run the system at operating temperature for 1 hour

Answer

Fill the system and check for visible leaks only

Answer

Test at normal operating pressure for 10 minutes