My boiler is making odd sounds somewhere within, any immediate concerns?

Q: My boiler is making odd sounds somewhere within, any immediate concerns?

A: Yes and no, perhaps, maybe … Not necessarily by intentional design, but most boilers are nearly silent in operation. Not having a blower to circulate warmth like a furnace, pumping water is generally quiet. Depending on the version of boiler and where it lies in the evolutionary chain, some do have small inducer fans. They are located on the unit and are required for proper combustion. Any fan or blower makes some noise although a problem here is pretty easy to pinpoint. A bit deeper into the boiler are where the burners are located. Once again, depending on the age and design, this important component can be buried inside or visible under the boiler. Noise in this area is usually intermittent but can be of a major concern. When the heating cycle begins, the burners should light off quietly and smoothly. We take for granted this safe containment of fire that otherwise could be dangerous or deadly. Typically, dirt and dust can be the culprit with burner problems. Combustion requires way more air than fuel and that air always contains some amount of airborne particulate (normal people call that dust). Some of that gets sucked in, swirled around and burned up, and after years this accumulation clogs up the works. No burner is immune, some are just more sensitive than others. The worry here is twofold; the basic operation can be affected to the point of failure and/or the fuelair ratio can be altered as to produce excessive amounts of carbon monoxide. This is one of the very good reasons we invest in combustion analyzers for all of our technicians. Sampling the exhaust is the very best way to know if any appliance is burning safely and efficiently. If you really want to know your numbers, give AirWorks a call. Deeper further into belly of the boiler lies the water jacket, otherwise known as the heat exchanger. It just contains the water that is heated and circulated around so what could possibly make “odd” sounds in there? Glad you asked, not a lot, but if its emanating from the core, meltdown is imminent. Not really immediately, but left unresolved things can get ugly. Depending on the design, the heat exchanger can be made of cast iron, aluminum, copper, stainless steel, or a combination of these. Any number of whining, rumbling, or popping sounds can indicate either low water flow rates and/or scale built up inside the boiler itself. Despite being called a “boiler,” they generally don’t ever boil. What happens when they start to often sounds very strange indeed. This is called “flashing to steam” and you don’t want to go there due to the fact that steam increases its volume over water 1,700 times with potentially powerful results. Yet another good reason to have your relief valve checked annually. Please remember many boilers only hold a small amount of water (3-4 gallons) and have really big burners, many times the output of your entire cooking range. Not moving enough water due to defective pumps, valves, air in the system, and scale build up will rob efficiency and reduce reliability. During our standard boiler maintenance calls we go through a detailed checklist with a focus towards safety, reliability, and last but not least, efficiency.