Submitting a water sample to OutdoorBoiler.com Labs is one of the simplest and most important steps you can take to protect your outdoor wood boiler from internal corrosion, and it costs you nothing.
Why Your Outdoor Boiler Water Quality Cannot Be Ignored
Your outdoor wood boiler works hard to heat your home. What most owners do not realize is that the water inside the system is quietly working against it.
The moment untreated water contacts steel, rust and corrosion begin. Over time, this thins the walls of your water jacket, causes leaks, and destroys an investment that should last decades. The damage is invisible from the outside until it is too late.
That is exactly why water treatment and regular water sample testing are not optional maintenance items. They are the foundation of responsible boiler ownership. In fact, failing to properly treat your boiler water will void your warranty. Your boiler manufacturer requires documented, satisfactory water test results to keep that warranty valid.
The good news: OutdoorBoiler.com provides a completely free water sample testing service. No lab fees. No hidden costs. Just clear, actionable results delivered to your inbox.
The Full Process at a Glance
Before diving into the details, here is the complete process from start to finish:
Each step builds on the last. Skipping or rushing any one of them, especially the flush before sampling or the labelling, produces unreliable results and wastes time for everyone.
Step 1: Submitting Your Water Sample
Get the Right Sample Bottle
You cannot use just any container. The sample must be collected in a proper sample bottle to avoid contamination that would skew your results.
Order a standalone sample kit. If you already have water treatment and just need bottles, the Outdoor Boiler Water Testing Sample Kit 2-Pack is available for a small charge plus shipping. Existing customers can order one package per year at no charge using the discount code FREEKIT at checkout (you pay shipping only).
Order Liquid Armor Water Treatment. Every gallon of Liquid Armor ships with two free water sample bottles, shipping labels, and shipping boxes everything you need included at no extra charge.
Every order of Liquid Armor ships with two complete sample kits at no extra charge.
How Much Liquid Armor Do You Need? (Sizing Chart)
The right dosage depends on your boiler's water capacity. Use this chart as a starting point. Your specific amount will be confirmed by your water test results.
Note: These are general estimates. 1 gallon of Liquid Armor treats approximately 200 gallons of system water. Your exact dosage depends on your local water chemistry, hard water areas, high mineral content, or a history of no treatment, which may require more. This is precisely why the free water test exists: to give you a number specific to your system, not a generic guess.
Not sure how many gallons your boiler holds? Common outdoor boiler water capacities by category:
Refer to your Outdoor Boiler Manual Guide for your specific model's capacity.
How to Collect the Sample Correctly
Following the collection instructions exactly matters. A contaminated or improperly collected sample produces unreliable results.
Process flow, collection day:
Here is the full step-by-step process:
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Safety first. Do not collect a sample while the boiler water is hot. Allow the furnace to cool before proceeding. Refer to your Owner's Manual for complete safety instructions.
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Flush sediment before sampling. Open the drain valve at the bottom rear of the water jacket and drain 5–10 gallons, or until the water runs clear, whichever takes longer. This removes sediment buildup that can produce a false or misleading test result. GX series owners should repeat this step at the second drain as well.
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If water does not run clear, you may have excessive sediment and should perform a full system flush. Remove any unburnt wood and ash before doing so the water jacket must remain full when there is an active fire in the firebox.
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Close the drain valve once the water runs clear.
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Add Liquid Armor at the dosage appropriate for your system (see sizing chart above). Allow for variation based on your water chemistry.
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Allow the water to circulate for a minimum of 24 hours before collecting the sample. This ensures the treatment is fully blended throughout the system.
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Collect the sample in the provided clean bottle. Do not touch the inside of the bottle or cap. Fill to the marked line.
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Label the bottle completely using the label provided in your kit. The following information is required directly on the bottle label not just on the shipping box:
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Your email address (the lab sends all results by email)
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Furnace serial number
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Furnace model
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Date the sample was collected
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Your full name and contact information
Practical Tip: Set a calendar reminder the day you mail your sample. Results take 3–5 weeks, and the 12-month retest window starts from your collection date not your results date. Owners who send in October, for example, should plan to send the following September again to stay ahead of the winter heating season.
What to Write on the Label Example
Many owners skip information or put it only on the box. Here is exactly what a correctly labelled bottle looks like:
The email address on the bottle is the single most important piece of information. Without it, the lab has no way to send your results.
Where to Mail Your Sample
Send your sample by US Postal Service only. FedEx and UPS cannot deliver to a PO Box and will return your sample, delaying your results by weeks.
Mail to:
OutdoorBoiler.com Labs PO Box 158 Shelby, MI 49455
The only physical drop-off location is the Shelby Post Office. The lab does not accept walk-in samples.
Common Mistake to Avoid: Several owners have mailed samples via UPS or FedEx, but both services returned the packages undelivered because of the PO Box address. Always use USPS, and use the pre-paid return label included in your sample kit.
Step 2: The Waiting Period: What Happens After You Mail It
How Long Does Testing Take?
Once your sample arrives at the OutdoorBoiler.com Lab, the analysis is performed using sophisticated testing equipment and a proprietary computer algorithm. The algorithm does not generate a generic report; it produces a customized result with specific instructions based on your exact water chemistry.
Typical turnaround: 3–5 weeks from the date your sample is received at the lab.
Plan for this timeline when scheduling your annual maintenance. Many owners send their samples during the same month every year, for example, always in September, before heating season, so results arrive before they need to fire up the boiler.
What the Lab Is Testing For
The analysis measures several parameters critical to your boiler's long-term health. Here is what each one means and why it matters:
The results are run through the proprietary algorithm, and you receive specific instructions not just a pass or fail, so you know exactly what to do next.
What if There Is a Problem With My Sample?
If your sample arrives damaged, mislabelled, or past its acceptable submission window, you will be contacted directly. This is another reason the email address on the bottle itself is critical; it is the primary way the lab reaches you with any questions.
Step 3: Understanding Your Results and What to Do Next
Reading Your Report: What Each Outcome Means
Your results will come in one of two forms. Here is how to interpret each:
Satisfactory Results
If your test comes back satisfactory, your boiler water chemistry is within the acceptable range and your system is properly protected.
The result will indicate that you should submit your next sample within 12 months of the date you collected the current sample, not the date you received results. Because testing takes up to four weeks, factor that into your scheduling.
Keep a copy of every satisfactory result. Your warranty requires you to maintain documentation of annual water analysis. OutdoorBoiler.com Labs keeps records as well, but it is your responsibility to have copies on hand. Satisfactory results are your documented proof of proper maintenance if a warranty claim ever arises.
Unsatisfactory Results: What Each Type Means and What to Do
An unsatisfactory result is not a crisis, it is the entire point of testing. The result will include specific, step-by-step instructions tailored to your water chemistry. Here are the three most common unsatisfactory scenarios and what happens next:
Importance of high conductivity: If you have a water softener connected to your home supply, you must bypass it every time you add water to your outdoor boiler. Softened water almost always produces a failed conductivity result and is genuinely harmful to boiler steel. This is one of the most common causes of unsatisfactory results we see.
Practical Tips From the Field
These are the mistakes we see most often and how to avoid them:
Tip 1 — Never use a rinsed household bottle. Even a thoroughly rinsed bottle carries trace residue from its previous contents. Soap, juice, or even plain water can alter pH and conductivity readings. Always use the bottle provided in your sample kit.
Tip 2 — Bypass the softener every time. Reconnecting to softened water after a system flush, even once, can contaminate the entire water jacket. Put a label on your softener bypass valve that says "Outdoor Boiler always bypass" as a physical reminder.
Tip 3 — Do not add more treatment than instructed. It is tempting to think that more is better. It is not. Excess inhibitors create their own chemical imbalance and can produce a failed test result. Follow the instructions precisely. If told to add 3 cups, add 3 cups, not half a gallon.
Tip 4 — Send your sample in the same month every year. Consistency removes the guesswork. Pick a month, September is popular because results arrive before peak heating season, and treat it like a scheduled maintenance appointment.
Tip 5 — Record your results in writing. Keep a simple log: date collected, date results received, result (satisfactory/unsatisfactory), and any corrective action taken. A single page stored with your Owner's Manual is sufficient and protects your warranty.
Frequently Asked Questions
Is the water test really free? Yes. We provide free water testing as part of our service to customers using Liquid Armor Water Treatment. There is no lab fee. For full details, visit our Free Water Testing Info page.
Can I test my boiler water even if I have a different brand of furnace? Yes. Liquid Armor and the free testing service work with any outdoor wood boiler. Note your furnace brand and the approximate water capacity on the sample bottle label so the lab can calibrate results accurately.
I switched from a different water treatment brand. Do I need to flush first? Yes. We recommend draining and flushing the boiler completely before switching to Liquid Armor. Some competing products are known to damage steel, and we cannot certify the quality of others. Bypass your water softener when refilling, add Liquid Armor at the correct dosage, circulate for 24 hours, and submit a fresh sample.
What if I do not have an email? Your test will still be performed. Allow four weeks, then call (231) 624-5765 with your name and furnace serial number to receive results by phone.
How do I know how much water my boiler holds? Refer to your Owner's Manual or the capacity chart on the Free Water Testing Info page. You can also contact us with your model and serial number.
What if I received an unsatisfactory result due to high conductivity twice in a row? If a second test still shows high conductivity after resubmission, you will be instructed to drain approximately half the boiler water and replace it with fresh, unsoftened water. To estimate how far your boiler has drained, time how long it takes to fill a 5-gallon bucket from the drain valve, then calculate the total seconds needed to remove half your system's capacity.
Am I responsible for keeping copies of my test results? Yes. Your manufacturer's warranty requires you to maintain copies of your annual water analysis results. We keep records on our end as well, but satisfactory results in your possession are your proof of proper maintenance for any future warranty claim.
Take the Next Step: Request Your Free Water Sample Test Today
We make the process as simple as possible. Order Liquid Armor Water Treatment and receive two free sample bottles with every gallon, or pick up a Water Sample Kit separately if you just need the bottles.
Follow the collection steps above, mail your sample to our Labs via US Postal Service, and we will handle the rest. You will receive a customized report by email with clear, specific instructions, no guesswork, no jargon, no lab fee.
Your boiler represents a significant investment in your home heating. Do not leave it unprotected.
