OFTEC Commissioning and Servicing 1 — Questions and Answers
Question 1: What is the first step when commissioning a newly installed oil-fired boiler?
- Check the installation complies with manufacturer instructions and Building Regulations (Correct answer)
- Light the burner immediately
- Set the room thermostat
- Fill the oil tank
Correct answer: Check the installation complies with manufacturer instructions and Building Regulations
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?
- A commissioning checklist/certificate and Building Regulations compliance notification (Correct answer)
- Only a verbal explanation
- A receipt for the oil used
- Nothing — no documentation is required
Correct answer: A commissioning checklist/certificate and Building Regulations compliance notification
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?
- To remove installation debris and ensure water circulation before applying heat (Correct answer)
- To check for leaks in the flue
- To test the oil pump
- To warm up the electrodes
Correct answer: To remove installation debris and ensure water circulation before applying heat
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?
- The overheat thermostat (limit stat) must be tested to confirm it shuts down the burner (Correct answer)
- Only the room thermostat
- Only the programmer timer
- No safety devices need testing
Correct answer: The overheat thermostat (limit stat) must be tested to confirm it shuts down the burner
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?
- Correct polarity, earthing, and that the supply is protected by an appropriate fuse or MCB (Correct answer)
- Only that it switches on
- Only the plug shape
- Electrical checks are not part of oil commissioning
Correct answer: Correct polarity, earthing, and that the supply is protected by an appropriate fuse or MCB
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).
Question 6: After completing combustion adjustments during commissioning, what should be recorded?
- All flue gas readings: CO2, CO, O2, flue temperature, smoke number, and calculated efficiency (Correct answer)
- Only the customer's name
- Only the boiler serial number
- Only the date
Correct answer: All flue gas readings: CO2, CO, O2, flue temperature, smoke number, and calculated efficiency
All combustion parameters must be recorded on the commissioning certificate: CO2%, CO (ppm), O2%, flue gas temperature, room temperature, net flue gas temperature, smoke number, calculated efficiency, and pump pressure. These form the benchmark for future servicing.
OFTEC Commissioning and Servicing 1
What is the first step when commissioning a newly installed oil-fired boiler?