Boilers are heavy-duty equipment that generate hot water or steam by burning fuel. Boilers generally operate under high temperatures and pressures. Given that they are subject to extreme working conditions, it is important to ensure that they are properly maintained – not only for reliability purposes but for safety as well.
More top checklists:
- Air compressors
- Air handlers
- Buildings Controls
- Chillers and cooling towers
- Fire alarms and smoke detectors
- Vehicles and fleets
- Also check out: How to Create a Preventive Maintenance Checklist
Note: This article was updated with new information in May, 2020
Is it safe to use boilers?
The short answer is yes – with proper operation and maintenance, boilers are now safe to use and have become an integral part to some facilities. It is useful to know, however, that this wasn’t always the case.
Since the early 1900s, government and professional organizations put resources into prioritizing the importance of boiler safety. They introduced codes, standards, and checklists to ensure that boiler safety is second-nature. These best practices have realized not only the reliability of equipment, but also the safety of the people that use them.
Types of Boilers
Boilers are generally one of three main types – fire-tube boilers, water-tube boilers, and electric boilers.
1. Fire-tube boilers
Fire-tube boilers operate by letting hot combustion gases flow through tubes submerged in water. This converts the water surrounding the tubes to hot water or steam. Fire-tube boilers operate at relatively low pressures of around 150 psi (~10 bar).
2. Water-tube boilers
With water-tube boilers, water passes through tubes surrounded by hot combustion gases. Its design allows for significantly higher pressures of up to 3500 psi (~240 bar). With higher operating pressures, this type of boiler has a broader range of applications – from small residential uses to larger industrial utility classes.
3. Electric boilers
As the name suggests, electric boilers generate hot water or steam from electrically heated elements. They are typically used in heating, ventilation, and air conditioning (HVAC) applications.
Critical Components of a Boiler
The critical components of a boiler directly impact its reliability and safety. These components include:
The single, most expensive part of the boiler. Problems with the drum are usually related to corrosion or excessive localized stress.
Next, headers act as outlets for superheated fluids. They can be susceptible to deformation from exposure to fluctuating high and low temperatures and thermal stresses.
These components are the most common causes of failure due to varying ranges of wear and tear. While tubing usually lasts for long cycles, localized stresses and corrosion can significantly accelerate its deterioration.
As with headers and tubing, piping systems can be subjected to excessive stresses from long-term operation under extreme heat and pressure conditions.
Lastly, these components must meet industrial standards for oxygen levels within the boiler. Without proper maintenance, they are prone to corrosion and deterioration.
The Importance of Preventive Maintenance for Boilers
Boilers play a critical role in a facility’s heating system. A comprehensive preventive maintenance program not only keeps your boiler up and running reliably, but also lengthens the life of your equipment and improves safety for employees.
Reliable boiler operation
Facilities rely on boilers for applications ranging from simple indoor heating to power generation and materials processing. If the boiler operates inefficiently or stops working entirely, it can negatively impact production. As such, keeping the vital components of boilers in good shape helps prevent process interruptions.
Even if the boiler is being used for climate control, that can still be important since it helps keep your facility worker-friendly, which can only help when it comes to productivity.
Wear and tear can strain your boiler system, and minor issues can negatively impact its efficiency. For instance, a leak somewhere may cause a drop in pressure, causing the system to use more fuel to keep to acceptable pressure levels. Another example would be if corrosion and buildup lead to inefficient operation.
The better you maintain your boilers, the less energy they’ll need to operate, resulting in cost savings from lower energy consumption.
Longer equipment life
When boiler components are allowed to deteriorate to the point of total failure, they take a toll on the whole system. A poorly maintained boiler will generally wear out faster than one that has been properly kept up, causing it to expire earlier than expected.
In addition, sometimes a breakdown warrants replacement by making repairs cost-prohibitive. In these situations, it becomes more cost-effective to replace a broken down boiler than to fix it. A solid PM plan can prevent the need for this kind of premature replacement.
As important as reliability and asset life are, they’re not the primary concerns associated with boiler failures. A fault that causes a boiler to break down can easily be hazardous to anyone working nearby, so much so that proper boiler maintenance is required by law.
By regularly inspecting the drum, headers, piping, and other components, maintenance teams can ensure that their boilers meet national and state standards, while also keeping their workers safe.
Recommended Boiler Preventive Maintenance Program
The first place you want to start is with your owner’s manual. This will provide you with the manufacturer’s recommended maintenance plan and upkeep suggestions.
Although more thorough inspections and maintenance on boilers occur just a few times during the year, it can be beneficial to complete a quick daily check to spot potential problems before they become major ones.
Technicians should notice leaking water, unusual noises, or obstructions. Check to make sure temperature and pressure readings are within range, and communicate any error codes to your service manager.
Each month, you should perform a more comprehensive inspection. Some of the things I would recommend checking include the combustion air piping and flue gas vent piping. You want to check for leaks, blockages, or signs of wear. Also check the relief valve discharge pipe and boiler relief valve for leaks. And, finally, check for blockages in the drainage system and lines.
Other items than can be tested or inspected on a bi-monthly or quarterly basis include the boiler hydronic piping, the burner flame, and the low water cutoff.
I would suggest bringing in a licensed service professional once a year to perform a complete inspection and conduct annual maintenance work. This trained and certified technician should rigorously test the boiler and repair problems, clean the heat exchanger, check connections and wiring, and test water pH levels.
Optimizing your boiler PM plan
If you already have a boiler preventive maintenance plan in place, it’s important to keep revising it to make it as lean as possible. Each planned task should be effective so as to avoid wasting time and resources. When applied over time, the cost savings can be significant—as much as 25% can be shaved off your maintenance costs by doing some planned maintenance optimization.
The workflow for boiler PMO often includes the following elements:
Begin with collecting PM data
Any decisions you make about your boiler’s preventive maintenance plan should be grounded in actual data. Storing work order data in your CMMS is a good way to start collecting useable data to use for boiler maintenance optimization.
In particular, the data you collect should include information on your boiler’s health, frequency of failures, completion times for repairs, and repair costs.
A less precise way to gather data, but fairly easy and potentially insightful, is to talk to your technicians. They can give you some ideas on which preventive maintenance tasks they feel are irrelevant or ineffective. Again, this is not a very precise source of data, but it could help you zero in on specific PMs for further analysis.
After you have collected data on your boilers for a while, it’s time to analyze it and see what trends you can find. The interval of time for each preventive maintenance task should coincide with estimated wear rates for the components they’re meant to treat, which is where data such as mean time between failures (MTBF) might come in.
If your data shows that you have a high number of corrective maintenance tasks for your boiler, it may be worth looking at whether your current PMs deal with those. If you aren’t doing the PMs needed to address those issues—or if your PMs are focused too much elsewhere—it can serve as a signal to make changes.
Adjust timelines on recurring tasks if needed
Some PMs may be performed too frequently, while others aren’t performed frequently enough. If they’re too frequent, then you’re over-maintaining your boiler, while under-maintaining it would leave gaps in your boiler maintenance plan.
For instance, if you’re running your boiler system less often than the average while still using a calendar-based maintenance schedule from the owners’ manual, you may want to adjust the frequency of PMs to match your runtimes. Using the actual number of hours to calculate when PMs are to be performed can save on maintenance costs and free up time to better focus your efforts.
On the other hand, if your PMs are designed to treat a failure mode that’s still occurring too frequently, then you may need to perform them more frequently—or look into whether they’re being performed correctly—in order to match the regular wear on the system.
Implement condition monitoring
In some instances, condition monitoring may be worthwhile. Using sensors to monitor drum pressure, track temperatures, or check for leaks can help you make sure PMs are performed only when they’re strictly necessary.
In addition, real-time condition monitoring can provide prompt data that allows you to handle problems as early as possible, potentially saving on repair and upkeep costs as well as heading off major safety hazards that may otherwise develop.
Study results and make improvements
As you implement changes in the preventive maintenance you perform on your boiler systems, you’ll want to continue tracking data. That data will help you determine what kinds of impacts your changes have.
Every so often, take the time to review the data on your boiler’s health. If you see a positive change, then you’re likely on the right track. If there are still issues that aren’t being treated, however, the data should give you a hint as to which changes are still needed.
Ultimately, PMO is a continuous effort. The goal is consistent improvement here, so a one-and-done solution isn’t likely going to be the best approach.
Additional PMO tips
In addition to the above steps, some additional PMO tips to implement with respect to your boiler maintenance include:
The more clearly outlined each PM is for your boiler, the more reliably your maintenance team will be in completing them, and the lower the odds will be that human error will get in the way.
Boiler Preventive Maintenance Checklist
Finally, the following checklist provided by the US Department of Energy is one of those valuable guides in making sure that proper routine checks are being made for boiler safety and efficiency. It can provide you with a baseline standard for what needs to be done and when it needs to be done. You can tweak these checklists to match your needs, as you gather data on effectiveness.