Winter is fast approaching, and that means it is time to take a look at your commercial or industrial boiler setup to make sure that it is prepared for any and all winter boiler problems. There are a number of things that can go wrong if your boiler reaches freezing or close to freezing temperatures that can cause critical damage or failures. Even if a freeze-up doesn’t cause permanent damage, the time needed to defrost a dormant boiler and prepare it to be brought back online can cause costly delays and set projects behind schedule.
The checklist of boiler safety precautions below provides a list of things that should be checked or completed before the temperature drops to ensure the health and continued up-time of your boiler. While these items largely apply to boilers that are outside of a climate controlled environment, there are things to consider with your stationary, permanent boiler installations as well.
Water pipes leading to and from your boiler can freeze just like the pipes in your house. This can lead to costly repairs, and even a “pipe burst” that can leave you with water flooding into crucial parts of your infrastructure. Make sure to follow these water lines and ensure that they are properly insulated and heated to keep them above 32° F at all times. Heat tracing these with either electrical or steam-based heating lines is crucial to your boiler surviving the winter. Remember: if your heat tracing is steam-based, it will only function when your boiler is running, and make sure that your heat tape is rated high enough for the temperature of the pipe.
Uninsulated and unheated fuel oil lines can cause your fuel to have a viscosity that is too high for your fuel pump, which will cause your fuel to flow improperly and can cause permanent damage to the pump in the worst case. In particular, standard #2 oil starts to gel at 17° F, so make sure that your lines stay above this lower limit. Beyond just heating and insulating fuel lines, consider switching to a winter fuel mix or a 50/50 mix with kerosene if using #2 fuel oil.
If you are unable to keep your boiler running constantly through the winter months, always be sure to drain the boiler and all related water lines. This will greatly reduce the risk of freezing for the static water, which is much more at risk than water that is flowing. If you do shut down your boiler, make sure to warm it up slowly when restarting. Increase the pressure slowly to give the metal and joints time to heat up evenly to prevent uneven expansion and possible breakage.
While not totally necessary, it’s a very good idea to put your boilers through a full inspection and service before the winter months. This will greatly diminish the chances of a critical failure or any other common winter boiler problems, and make sure that your boiler is running at peak efficiency as your steam needs and fuel consumption increase. This investment will quickly show positive returns in increased efficiency, reduced fuel consumption and reduced risk of failure.
One item worth checking, in particular, is refractory. While all boilers will show some cracking due to the extreme temperature changes leading to continual expansion and contraction of all materials and connections, it is important to make sure that the refractory is not excessively cracked when heading into the freezing months.
Boilers are designed for ~70° F combustion air. Air that is cooler than this will cause the firing rate to increase, and increase your operating cost. Much colder combustion air entering the room can cause issues if the air is passing across water lines that are under static conditions. Keep an eye on your stack temperature and its differential from the steam temperature. As a rule of thumb, the stack temperature should never be more than 150° F higher than the steam temperature. This is a sign of poor heat transfer which causes the efficiency of the unit to drop and can be a sign of serious issues.
While certainly not an issue that is unique to the cold weather months, it is imperative to make sure that there is at least a certain amount of heat transfer medium, usually water, in the boiler at all times. Otherwise, the furnace temperature will continue to rise with nowhere for the heat to go, which can cause overheating and a meltdown within the boiler. We have seen liquid steel pour out of a boiler like melted candle wax! This could be a result of a frozen feedwater pump or water cutoffs and is a sign that you need to put immediate attention towards thawing or fixing these.
While some businesses may have in-house boiler operators with the technical knowledge to handle these boiler problems themselves, these are serious issues and we always recommend seeking professional assistance for boiler repairs. With boiler freezing issues in general, there is a very high chance that something will need to be replaced, so make sure to perform a thorough inspection of all critical components if handling this yourself. Also, if attempting to defrost pipes or tanks filled with water, make sure to open some type of release valve in the area that you are heating. Otherwise, the ice can quickly turn to steam, causing a dramatic increase in pressure, and with nowhere for the steam to go, this can lead to serious and dangerous ruptures.
Carefully paying attention to these things will reduce your risk of failure, increase running efficiency and help you avoid the need for emergency boiler service during the winter months. As always, let us know if you have any questions. If you would like one of our Boiler Operators to come out and handle these winter boiler safety precautions for you, just let us know. We’d be glad to. Our certified operators know boilers inside and out, and there’s no better way to ensure that your boilers are safe, than to place them in our capable hands.