Combustion safety is a critical topic for FMs. The tragedy at the Star Spencer School is not the only hot water tragedy that has occurred – it is only one of the most devastating. And like all such explosions, it could have been prevented.
The fact that a boiler inspector has been to your site or that you have an annual inspection certificate from the state may not mean much. In most states these inspections are jurisdictional, which means they cover only specific things on very specific pieces of equipment.
In many cases, they do not include hot water heaters. If they do, the inspections may not cover burner firing controls. Some visual inspections detect only obvious defects in the pressure vessel, possibly failing to identify a looming problem.
This article describes practical steps you can take to prevent a water heater explosion in your facility. Combustion expert John Puskar, President of Prescient Technical Services in Cleveland, offers the following steps to ensure that your facility and water heater are safe. John identifies flammable gas piping and fuel-fired equipment hazards and is also the author of Fuels and Combustion Systems Safety: What You Don't Know Can KILL You.
To protect your occupants, consider these three steps:
1. Replace the safety relief valve at least every three years.
Aside from the fact that safety relief valves can accumulate deposits that render them ineffective, there have been a number of recalls. They should be inspected and tested regularly, but because they are so inexpensive, you are better off replacing them on a regular basis. Check out the manufacturer’s recommendations for maintenance and replacement.
For a commercial unit, call a professional. There is probably an expansion tank that should also be checked. The specific model of relief valve you need will probably be available only from a commercial supply house.
And while you are thinking about your facility’s combustion equipment, don’t forget your water heater at home. You can buy a relief valve at a home improvement store. Make sure your unit is safe to work on (water off, system not hot or firing). The cost of this repair is less than $50. There are plenty of YouTube videos out there to show you how to do this.
2. Verify that the combustion system controls and venting are working properly.
- Does the burner’s “off cycle” work properly and accurately?
- Does the burner light easily, without an audible sound or poof? Look for a blue flame, not orange or yellow. Also look for lint and other contaminants around the burner air intake and clean as necessary.
- Are flue gases going up the chimney and not into the facility? This can be tricky to judge because when it’s cold there can be momentary back flow. However, after a few seconds, it should be obvious whether combustion products are spilling into the space. You can usually check this at the draft diverter flue outlet, but be careful not to burn your hand. Try lighting a match and then extinguishing it near the draft diverter outlet, then watch the smoke.
3. Check for leaks and address any issues.
- Any odor of gas? Sometimes you can’t smell it, so use a soap solution on the piping, especially near joints.
- Do you have any water leaks? Water leaks can be evidence of a tank that is compromised. These can also be an indication that the safety relief valve is leaking or that the piping system is under excessive pressure.
If you have any doubts about your abilities, call a competent local plumbing contractor for help and ensure that your water heater gets the attention it is due.