Boilers and Low Water Cutoff: Mechanical-Float Valves
Low Water Cutoffs (LWCOs) for boilers are required by code in many states and municipalities, regardless of whether the boiler heating system is in a commercial building or a residence. While more modern LWCOs are typically electronic, many older boilers have mechanical-float valves, which raise and lower with the water level and are attached to a switch. If the water level gets too low, the float moves the switch into the off position, causing the boiler to shut off.
Unfortunately, these LWCOs are prone to failure in a number of different ways, and when they fail, those insurance claims can fall into the laps of adjusters like you. Should you get one of these claims, you’ll want to know what you’re dealing with and what the claim could mean for your customer and your company. You’ll want to know:
What can go wrong with Mechanical-float LWCOs;
The consequences of these failures;
How they can cause total and catastrophic system failures;
The financial impact of LWCO failure; and
How to prevent such failures.
HVACi has made it simple to learn all of this with our straightforward, short whitepaper on Mechanical-Float LWCO Valves — crafted by our experts for insurance adjusters. Get yours by filling out the provided form!
If the weather outside is frightful — or maybe just a bit chilly — it’s time for many to flip their HVAC systems from cooling to heating, and with that comes a slew of claims related to different heating systems. When these claims hit your to-do list, you want to be confident in your evaluations and settlements, which means you need to know at least the basics of how these systems work.
Rather than burying yourself in books and schematics, spending hours you don’t have trying to learn as much as you can, take a look at HVACi’s HVAC Winter Concepts Webinar. In this recorded webinar, we take a look at:
How different heating systems work (i.e. boilers, heat pumps, and furnaces);
How efficiency is measured for heating systems;
What types of claims you might see for each system type;
And more.
Our 90-minute webinar explains all of these facets of HVAC heating systems in a straightforward, concise manner specifically designed to provide insurance adjusters with the information you need to know. Plus, you can pause it so you can watch in your own time.
Don’t wait! Fill out the form to access the HVAC Winter Concepts Webinar and prepare for those winter claims to blow in.
IMPORTANT: Previously recorded webinars do not qualify for continuing education credit.
As an adjuster, insurance is your area of expertise. If you’re not also an expert on the inner workings of gas furnaces, you may find yourself a little stumped when an estimate hits your desk. That’s okay! After all, such claims may not come to you every day. But when a gas furnace claim does cross your desk, you want to know how to evaluate estimates and make the right call, and you need the right tools to help you do that.
If you don’t know how gas furnaces work already, you don’t need to spend hours poring over a textbook to get the information you need as an insurance adjuster. We’ve already done that for you and created a video that explains it in a little over 90 seconds.
It couldn’t be much easier! Get your free gas furnace instructional video now by filling out the form provided.
Boilers are a relatively common way of heating a home or business, but the complexities of these sophisticated machines aren’t common knowledge. When they break, it’s not always immediately clear what damaged them, if the loss can be covered, or whether they can be repaired.
If you’re an insurance adjuster dealing with a boiler damage claim, you want to understand what parts are actually damaged in the assessment and estimate, as well as how they are critical to the boiler’s function. That’s exactly why we at HVACi have put together an easy-to-use schematic with a glossary of parts. Our simple guide not only shows you what the names of the parts are but also concisely explains the function of each one in straightforward terms. It’s a great tool to keep on hand for when those boiler claims roll in and you need to be on your A-game.
Get your Boiler Schematic and Glossary by filling out the form provided.
When the seasons change and winter temperatures settle in, homeowners fire up their heating systems for the first time and carriers begin to see an influx of furnace and boiler claims. A common issue seen with these systems is the messy and potentially dangerous phenomenon known as a puffback. A puffback can be triggered by a variety of causes that all typically stem from a lack of maintenance or age-related wear & tear. Due to the potentially complicated nature of these types of claims, it is essential for adjusters to understand how puffbacks occur and how heating systems can successfully be restored to pre-loss condition following this type of event. Download our Puffback Overview to prepare for winter property claims this year and tackle puffback related losses with confidence.
Learn even more detail about furnace and boiler puffbacks and how the causes are diagnosed by checking out our blog.
According to the Insurance Information Institute, Water and Freeze Damage claims are among the most severe property claims, with an average settlement of over $10,000. With the severity and frequency of this claim type, it is essential for adjusters to understand how HVAC systems can be affected by this type of damage. To make matters more complicated, an insured’s HVAC system can be both the victim and culprit of the freeze damage, particularly if a boiler is involved. Boilers function by pumping hot water or steam throughout the home, and therein lies ample opportunity for the pipes to freeze or burst under the right conditions. While freeze damage most frequently occurs with boilers, our HVAC System Freeze Damage Adjuster Guide reviews the types of HVAC systems that are susceptible to this damage type, along with the common causes of Freeze Damage.
The following HVACi article on “The Dangers of Freezing Water & Boilers” originally appeared in the Technical Notebook Column of Claims Magazine and was also published on Property Casualty 360.
Figure 1 and an inside view of a stuck, low-water cutoff in a boiler
Although failsafes against significant boiler failures do exist and continue to improve, they remain far from perfect.
One particularly susceptible failsafe is a boiler’s low water cutoff (LWCO). An LWCO is designed to alert the boiler that it does not contain sufficient water to “fire,” and prevents the boiler’s burners from igniting until a safe water level has been restored.
Installation of low water cutoffs
Because these types of failures can lead to injury or death, most state and municipality codes require the installation of low water cutoffs for both residential and commercial boiler applications.
LWCOs are found in one of two designs: Electronic-probe (a more recent technological introduction) and mechanical-float (a traditional, lower-tech version, seen in Figure 2). For this article, we’ll focus our attention on the latter.
What is a mechanical-float LWCO?
Mechanical-float low water cutoffs are the most widely used water-level safety device in residential and commercial heating boiler applications. These LWCOs are simple in design and function much like fill arms found in residential toilet tanks. As the water level drops in a boiler reservoir, the buoyant arm “floats” down until it reaches a point at which the boiler is unsafe to operate, and the switch turns the heating system off as illustrated in Figure 3.
Common issues with LWCO valves
Despite their simplistic design, mechanical-float LWCOs are prone to several issues, which can have catastrophic impact if not addressed. These issues include:
Stuck valves: Mechanical-float LWCO valves are in constant contact with supply water, and are exposed to minerals, dirt, rust and other total dissolved solids (TDSs). This prolonged exposure to TDSs can interfere with the designed function of the float, preventing it from moving freely up and down in line with the actual water level.
Clogged LWCOs: Sometimes, TDSs and other impurities can prevent the free-flow of water through the LWCO, and can “trick” the LWCO into reporting that an adequate supply of water is present in the boiler, when in fact the minimum safe water level has been breached.
Consequences of LWCO failure
If the float is prevented from moving freely and from sending the appropriate signal to the boiler controls (and the burner) to shut down the boiler when the minimum safe water supply level has been breached, the boiler may continue to run without water (or may be allowed to start without water present).
If a boiler operates without the necessary water supply, the heat generated in the boiler’s combustion chamber does not transfer to the water supply, and causes the burner, heat exchanger, and/or boiler tube(s) to overheat. With prolonged or repeated exposure to this condition, the walls of the burner, boiler or heat exchanger may weaken and ultimately crack, as seen in Figure 4.
Freezing conditions, when coupled with LWCO failure, can lead to catastrophic system failure. Should the feedwater pipes for the boiler become frozen (a common occurrence during cold winter months), the system will be starved of water. If the LWCO simultaneously malfunctions, the boiler will start and run without an adequate supply of water.
The cost of LWCO failure
When the heat exchanger or boiler tubes crack or fail, the cost associated with the required labor and parts to repair the boiler (provided the parts are still available since boilers can remain in service for dozens of years) often outweigh the cost of the replacement. The failure of a relatively inexpensive component (usually between $200 and $600, plus installation) can ultimately lead to a residential settlement in excess of $10,000.
Mechanical-float failure prevention
Mechanical-float LWCO valves should be regularly “flushed” to remove TDSs which can prevent the float from moving freely as the water level within the boiler changes. Most manufacturers recommend flushing the boiler at least once per season (some field technical experts say as often as weekly) by opening the “blow down valve,” which sits beneath the LWCO line and allows harmful deposits to escape. Boiler feedwater should be chemically treated to prevent scaling and to maintain proper pH levels for optimal boiler efficiency and performance.
The prevalence of boilers in residential and commercial heating applications makes the threat of LWCO failure real.
