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An In-depth Analysis of Fuel Burning Equipment Fires

February 15, 2022

Heating equipment is one of the most common causes of fires in Canada, possibly due to the length and severity of our winters. However, fires are usually a result of something more commonplace and almost entirely preventable. Most fires caused by fuel-burning equipment result from maintenance and installation issues.

Top causes of fires in Canada

  1. Cooking and cooking equipment (46%)
  2. Heating equipment (16%)
  3. Electrical (9%)
  4. Intentional or incendiary fires (8%)
  5. Smoking (5%)
  6. All other fires (16%)

Our long winters mean we require heating equipment for seven to eight months of the year. Hence it is among the most common causes of fires in the country.

Common causes of heating equipment fires

Most of the heating equipment fires we investigated resulted from a lack of, or poor maintenance, and failure to clean heating equipment regularly.

  • Clearance to combustibles – Normally involves installing equipment too close to combustibles.
  • Venting issues – These are common in fires and carbon monoxide incidents. When the venting is too close to combustibles, vents could crack or get blocked. When a vent is blocked, the flame exits the bottom of the equipment and ignites combustibles near the equipment.

Types of maintenance

Almost all heating equipment fires are preventable with proper maintenance and thorough adherence to installation procedures. The type of maintenance and intervals between maintenance vary depending on the manufacturer. Most manufacturers require at least a yearly maintenance schedule. Types of maintenance actions include, but are not limited to:

  1. Removing and cleaning the burner and manifold –The manifold refers to valves and operating equipment that delivers gas to the burner. They usually come out quickly, especially when removed by an experienced technician. However, cleaning the burner and manifold is essential during maintenance.
  2. Inspection of the venting is a crucial step in checking for blockages. You also need to perform a venting check on atmospherically vented equipment. Atmospherically vented equipment takes air from the building and directs it outside. Older equipment usually has a draft hood on top to fulfill this function. Most water heaters still have a draft hood or draft diverter, and they use interior air to ensure that the venting goes up the chimney properly.
  3. Cleaning the heat exchanger, boiler fin tubes, or refractory – The heat exchanger is part of the system where the gas or oil burns. It usually requires a certain amount of cleaning, but not a lot. Boilers are different; they need cleaning in-between the fin tubes or refractory. Fin tube equipment is typically older because most of the equipment is moving to high-efficiency boiler systems. These systems still have fin tubes, but they usually require treated water.
  4. Checking all safety and limits and recording settings of limit controls – You need to ensure that the safety works on every piece of equipment.
  5. Checking the inlet gas and manifold pressure ensures that the gas supply is within the manufacturer’s specifications.
  6. Inspecting the heat rise on forced air appliances – You need to ensure that the heat rise is within the manufacturer’s specifications. The heat rise is on the manufacturer’s reading plate, and you must match your equipment to the specified number. During these checks, you must ensure that the equipment has high efficiency. For example, if there is too high fan speed on some pieces of equipment, efficiency decreases because you’re not picking up the heat off the heat exchanger. You can adjust that during maintenance.
  7. Lubricating and oiling all moving parts of the equipment – This usually includes pumps and motors. However, many newer equipment pieces don’t require it because they have sealed motors.
  8. Checking for gas leaks on any portion of the equipment is generally done during the equipment reassembly after maintenance. Therefore, it is a vital step of the maintenance process.
  9. Doing a flue gas analysis with electronic equipment – This is done after maintenance to determine the firing characteristics of the equipment. There’s a piece of equipment you can purchase to conduct the analysis. You would put it into the vent to get information on the equipment efficiency, vent temperature, and delta temperature.
  10. Test fire the equipment after reassembly for operational purposes
  11. Document the service and maintenance performed – It’s crucial to do this with numeric documentation for gas manifold reading and limit settings. When checking a number, that number should be on the service and maintenance record. It makes it easier for technicians and investigators to confirm if the equipment was operating within the manufacturer’s specifications during maintenance. Documentation of the maintenance performed should be supplied to the equipment owner and kept on file with the maintenance provider.

Considerations when employing service personnel

You need trained and competent service personnel conducting the equipment service and maintenance. The B149.1 National Gas Code states that “personnel performing installation, operation, and maintenance work shall be properly trained in such functions.” Each jurisdiction has specific requirements. Some jurisdictions require certification to conduct service and maintenance functions. Certification requirements would include the successful completion of a training program that is approved by provincial legislation.

Technicians should be familiar with the equipment on which they are working. They should always reference the manufacturer’s instructions and documentation before working on the equipment.

Case study 1: Carbon monoxide poisoning at a motel

Figure 1: A Super 8 motel in Winnipeg, Manitoba.

A carbon monoxide poisoning incident sickened 46 people at a motel in Manitoba. Usually, carbon monoxide is burned in the equipment. However, it can escape the equipment ventilation and leak into living spaces.

In this case, the equipment was not maintained properly. When we removed the top of that equipment, the boiler system was plugged up entirely. The improper maintenance caused the equipment to malfunction and leak carbon monoxide into the living space.

Such incidents have an increased likelihood of litigation. However, litigation could take years to conclude due to the high number of victims.

Case study 2: Carbon monoxide poisoning

A building owner in Winnipeg contracted a company to conduct maintenance after having issues with the equipment. The company provided three separate service technicians to try and fix the problem. People in the building mainly complained of dizziness and headaches. However, this was not adequately diagnosed or fixed by the maintenance company. As a result, the building owner died from carbon monoxide poisoning.

We discovered that a blocked chimney caused a carbon monoxide leak during our investigation. There were several problems with the insulation, but the main problem was improper maintenance. The contractors who did the care and service on the equipment did not check if it was venting correctly. It resulted in carbon monoxide leaking into the space.

Figure 2: The Winnipeg building that had a carbon monoxide leak

The maintenance by the contracted company was not performed according to the manufacturer-certified instructions or the maintenance agreement that was signed with the deceased. As a result, the widow took legal action for wrongful death against the service company, settling the case out of court.

Key takeaways from the case

In cases involving fire or a carbon monoxide incident caused by heating equipment, the fuel expert will help you prepare a report before submitting the case for trial. Despite joining this investigation later, we could piece everything together because it was well-documented by the Fire Commissioner’s Office in Manitoba.

Case study 3: Boiler blockage

Unclean equipment can create a carbon monoxide hazard in occupied spaces. For example, years of buildup in a boiler can create a carbon monoxide incident, which happened in this case. The equipment shown in figure 3 has never been cleaned since installation.

When cleaning the boiler, you must thoroughly clean the fins. In a boiler blockage incident, fire shoots through the bottom of the boiler, meaning either the boiler or the vent is blocked. Blockage issues are always the result of improper maintenance or lack thereof. For example, suppose a flame at the bottom develops into a carbon monoxide problem. There are also incidents where you could ignite combustibles around the boiler.

Figure 3: An example of a piece of equipment clogged up with lime and debris.

Questions to ask when investigating blockage-related claims

  • How old is the boiler?
  • Do you ever have it serviced, and how frequently?
  • Have there been any recent repairs or maintenance done to the boiler?
  • Who did the work?

Case study 4: A propane heater fire

A builder placed propane heaters in homes under construction, which resulted in four houses burning.

Figure 4: Types of propane heaters

Propane heaters are usually found in residential spaces. The industrial ones are typically used during building renovations or construction. They all have different maintenance requirements and apparent combustible issues.

Figure 5: The building site after the incident

In this case, the propane heater on the construction site was placed on top of the straw. The heater had no non-combustible base, usually set to prevent fires (see figure 6).

Figure 6: The propane heater at the first home we visited during the investigation.

Construction workers who place propane heaters in homes need proper training. Otherwise, they must be held liable for damage that could result from one of these heaters not being utilized according to the manufacturer’s instructions.

Figure 7: The construction heater that caused the fire.

The propane heater in figure 7 burned the concrete. We concluded that the heater ignited the straw, which melted the propane hose. Cylinder pressure under that hose ignited into the basement, causing enough heat to damage the concrete on the side.

Common causes of propane heater fires

  • Clearance to combustibles – All appliances fueled by natural gas, propane, or fuel oil require clearances around the device and in the vent. Otherwise, they could cause a fire.
  • Hose connections and lengths – The hose connections need to be suited for the equipment being used.
  • Heaters are not used according to the manufacturer’s instructions.
  • Clearance requirements are not being observed – The water heater in figure 8 indicates unobserved clearance requirements. Often, clothes get placed at the bottom of the water heater, and they could ignite from the heat at the bottom. Fires like these are preventable.

Figure 8: A water heater without clearances.

When investigating such cases, you need to secure the evidence and ensure that the scene is undisturbed until an expert arrives.

Questions to ask when investigating construction-related claims

  • What was their method of heating the construction site?
  •  What kind of heaters were utilized?
  •  Was the fuel natural gas or propane?
  • Who was connecting the heaters?

Talk to the person who placed the propane heaters to see how knowledgeable they are about the clearance requirements of their work, then hand this information to the investigator so they can follow up with the person.

Case study 5: Gas explosion

A home burned due to a gas leak.

Figure 9: What remained of the home after the gas explosion.

In some cases, fires are synonymous with explosions, especially where natural gas is concerned. Such explosions are not as usual with propane, but they can happen.

Figure 10 illustrates how ubiquitous the gas is in a typical home. It starts at the meter on the outside (far left) and travels through the tubing that brings the propane or natural gas inside the house. This gas is used in water heaters, fireplaces, cooking equipment, and other appliances.

Figure 10: An illustration of how gas travels in a home.

All the components in figure 10 must be eliminated as possible explosion sources when investigating a gas explosion.

Causes of gas explosions

  • Faulty workmanship includes improper installation or a contractor leaving leaks in the piping.
  • Underground leaks from utility piping – When investigating a gas explosion, it’s essential to ask the insured about any recent maintenance work on adjacent streets. Ask about recent underground work where contractors may have inadvertently hit a natural gas line. In such instances, the natural gas leaks underground and into homes, resulting in a gas explosion.
  • Misuse of fuel – Incorrect storage and use of propane cylinders could lead to gas explosions. Using the wrong fuel for equipment can also cause an explosion.
  • Arson – Self-inflicted or criminally motivated gas explosions.

Gas explosion investigations are incredibly complex because of the numerous gas appliances found in typical buildings. In addition to the fuel appliances, we need to consider compressed gas containers or aerosols that could cause explosions. When investigating such cases, you need to document the physical evidence or lack thereof to protect yourself from a liability standpoint.

Questions to ask when investigating gas explosions

  • Has there been any recent servicing done to the gas meter?
  • Has there been construction on the street lately?
  • Who was in the home?
  • Have there been fatalities?

Case study 6: Fatal carbon monoxide poisoning

A Woodstock family of four died from carbon monoxide poisoning. Carbon monoxide from their unmaintained fireplace filled the home and overcame all family members. The fireplace was running all night and producing carbon monoxide at a level of 400 to 500 PPM in the basement.

The fireplace was at least eight years old. The father forgot to turn it off when he went to bed, and the whole family had carbon monoxide poisoning symptoms at night. Investigators found vomit buckets next to everyone’s bed. Vomiting is a symptom of carbon monoxide poisoning.

This case resulted in the requirement of carbon monoxide detectors in homes due to a private member’s bill in the legislature. The woman’s uncle who died called attention to carbon monoxide poisoning and the need for carbon monoxide detectors in homes.

Safety measures to prevent fuel-burning equipment fires

It is unsafe to store propane cylinders inside the home. During a fire, gas cylinders can turn into rockets very quickly. Moreover, propane cylinders can leak, which is never a good situation to have inside your home.

The maintenance of gas equipment can save lives. The best and easiest way to mitigate problems with fuel-burning appliances is maintenance. Almost all manufacturers have a maintenance section in the installation instructions. So, it would help if you ran maintenance checks at least once a year through an experienced and certified contractor. Inspect gas fireplaces, equipment, furnaces, water heaters, and anything that runs on hydrocarbon fuel.

Contact Our Experts at Origin and Cause

Our forensic experts and investigators have extensive knowledge and field experience when it comes to uncovering the cause of fuel-burning equipment fires. We base our conclusions on facts alone to derive the correct answers to what caused the failure. Contact us at 1-888-624-3473 for more information.