OFTEC Commissioning and Servicing

Question 1

What is the first step when commissioning a newly installed oil-fired boiler?

Accepted Answer

Check the installation complies with manufacturer instructions and Building Regulations

Answer

Before operating the appliance, the technician must verify the complete installation complies with manufacturer specifications, Building Regulations, and OFTEC Technical Standards. This includes checking flue, oil supply, ventilation, and electrical connections.

Question 2

What document must be completed and left with the customer after commissioning an oil-fired appliance?

Accepted Answer

A commissioning checklist/certificate and Building Regulations compliance notification

Answer

A commissioning checklist recording all test results must be completed and a copy left with the customer. For OFTEC registered work, Building Regulations notification must also be submitted. This provides a permanent record of the installation.

Question 3

Why must the heating system be flushed and filled before firing the boiler for the first time?

Accepted Answer

To remove installation debris and ensure water circulation before applying heat

Answer

The heating system must be flushed to remove flux residue, solder debris, and manufacturing contaminants that could damage the boiler and pump. Filling and venting ensures proper water circulation before heat is applied, preventing localised boiling.

Question 4

What safety device must be tested during the commissioning of an oil-fired boiler?

Accepted Answer

The overheat thermostat (limit stat) must be tested to confirm it shuts down the burner

Answer

The overheat thermostat (high-limit or limit stat) is a critical safety device that shuts down the burner if the boiler water temperature exceeds a safe limit (typically 90-100°C). It must be tested to ensure it operates correctly.

Question 5

What must be checked regarding the electrical supply to the oil burner during commissioning?

Accepted Answer

Correct polarity, earthing, and that the supply is protected by an appropriate fuse or MCB

Answer

Correct electrical polarity (live, neutral, earth) must be verified as many burner control boxes are polarity-sensitive. The earth must be sound, and the circuit must be protected by an appropriate fuse or MCB (typically 3A or 5A).

OFTEC Practice Test

OFTEC Practice Test

OFTEC Commissioning and Servicing