OFTEC Commissioning and Servicing 2

Question 1

What are the key checks included in an annual oil boiler service?

Accepted Answer

Combustion analysis, heat exchanger inspection, flue integrity, oil supply, controls, and safety devices

Answer

A comprehensive annual service includes: combustion analysis, heat exchanger cleaning and inspection, flue gas spillage test, nozzle replacement (as needed), filter cleaning/replacement, safety device testing, oil supply checks, and controls verification.

Question 2

Why should the oil nozzle be replaced during a service, even if the burner appears to be working well?

Accepted Answer

Nozzles wear over time, changing the spray pattern and degrading combustion before problems become obvious

Answer

Oil nozzles erode gradually from the high-pressure oil flow, changing the spray angle and flow rate. This degradation occurs before any visible symptoms appear. Replacing the nozzle annually (or as per manufacturer guidance) maintains optimal combustion.

Question 3

What should be inspected when examining the heat exchanger during a boiler service?

Accepted Answer

Soot build-up, signs of corrosion, cracks, and any evidence of water leakage

Answer

The heat exchanger must be inspected for soot accumulation (which reduces efficiency), corrosion (which could lead to CO leakage), cracks (which are a CO hazard), and any signs of water leakage from the waterways side.

Question 4

What is the purpose of cleaning the photocell during an oil burner service?

Accepted Answer

Soot or deposits on the photocell can prevent it from detecting the flame, causing nuisance lockouts

Answer

The photocell (flame sensor) detects flame by sensing UV or visible light. If the lens becomes coated with soot or oil deposits, it cannot detect the flame properly, causing the control box to lock out even though a flame is present.

Question 5

When servicing an oil boiler, what condition of the ignition electrodes would require replacement?

Accepted Answer

Cracked porcelain insulation, heavily pitted or eroded tips, or carbon build-up bridging the gap

Answer

Electrodes should be replaced if the porcelain insulator is cracked (causing short circuits), tips are heavily eroded (weak spark), or carbon deposits bridge the electrode gap (preventing spark). Otherwise, clean and re-gap to manufacturer specification.

OFTEC Practice Test

OFTEC Practice Test

OFTEC Commissioning and Servicing 2