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How To Keep a Pellet Stove From Rusting (9 Effective Tips)

Most pellet stoves are made of cast iron and are thus vulnerable to rust. Pellet stoves with ceramic components still have some steel and cast iron parts, meaning they are not entirely rust-proof. So, you need to know how to keep a pellet stove from rusting throughout the warmer months. 

Here are 9 ways you can keep a pellet stove from rusting:

  1. Remove all leftover pellets from the burn pot and hopper.
  2. Clean the pellet stove thoroughly, including the exhaust.
  3. Use a pellet stove vacuum to eliminate ash and soot.
  4. Cover the outdoor cap of the flue, exhaust, or chimney.
  5. Treat the metal parts of the pellet stove with WD-40.
  6. Consider moisture-absorbing or rust-inhibiting products.
  7. Remove existing rust and use high-heat spray paint. 
  8. Use a dehumidifier when the relative humidity spikes.
  9. Clean and maintain the pellet stove per the manual.

If your pellet stove already has some rust, you must restore it before using some of the solutions in this guide. Otherwise, you can proactively prep your pellet stove to be substantially rust-proof. Read on to learn about the various effective ways to keep a pellet stove from rusting. 

1. Remove All Leftover Pellets From the Burn Pot and Hopper

The first step to consider is a thorough cleaning as winter bids farewell. While the cast iron is materially susceptible to rust, one of the most efficient facilitators of rusting is the leftover pellets in the stove, i.e., the burn pot, auger, and hopper. 

You may have unused pellets in the hopper. Also, some partially burnt pellets may remain in the burn pot or combustion chamber after you stop using the stove. These pellets are a magnet to ambient moisture, i.e., humidity. 

Like others, you have probably taken great care to keep the pellets dry throughout the winter. But if you leave the unused or partially burned pellets in the stove, these will cause extensive rusting inside the appliance. Also, the rust and corrosion may be severe. 

Fortunately, the solution is as straightforward as removing all the leftover pellets from the entire feeder system. Your pellet stove may have a top-loading hopper or a horizontal feeding system. Irrespective of such variations, remove all the pellets before you begin cleaning the stove. 

You can pack the unused pellets in a sealed bag and store them in a dry place so that you have some stock for the next season. However, do not mix these pellets from the hopper with fresh or new supplies. Dispose of the partially combusted pellets from the burn pot.

2. Clean the Pellet Stove Thoroughly, Including the Exhaust

All pellet stoves require an end-of-season cleaning. This necessary annual routine should be as thorough as possible. Thus, you need to clean the pellet stove inside-out, including the exhaust.

Here are the preliminary steps to cleaning a pellet stove:

  1. Unplug the pellet stove and wait for it to cool to your room temperature. 
  2. Remove the ash pan and empty it safely as recommended by the manufacturer.
  3. Use a paintbrush to clean the dry ash, soot, dust, and other debris inside the stove.
  4. You can use a rag to grab the loose dirt or let it be for the vacuuming round. 
  5. Alternatively, you may use mild soap and water to clean the stove with a damp cloth.
  6. You may use a scrub pad and sandpaper to remove rigid debris in the stove.
  7. Refer to the manual to remove and clean the detachable components, like the burn pot.
  8. Use the cleaning tools, like the poker for the burn pot, provided by the manufacturer. 

Here’s a short video about cleaning a Vicenza pellet stove:

You need a flue cleaning brush to work on the exhaust pipe. If you don’t have one, you can check out the Chimney Brush Pellet Stove Vent Brush with Handle (available on Amazon.com). This vent, flue, or exhaust brush has a 10 feet (3 meters) flexible handle, which will probably suffice for most installations. 

Here are the steps to clean a pellet stove’s flue, vent, or exhaust:

  1. Check the manual to locate the exhaust sensing probe (ESP) in your pellet stove.
  2. Remove this thermistor before you start cleaning the flue vent or exhaust pipe.
  3. Go to where the exhaust pipe juts out of your wall and use the vent brush to clean it.
  4. You may use a drill to hook up the vent brush and motorize the cleaning routine. 
  5. Set the drill to forward, not reverse, to navigate the exhaust system of your pellet stove.
  6. Loosen as much soot, ash, dust, and dirt as you can before vacuuming.  

This entire cleaning process is vital if you wish to keep a pellet stove from rusting. All the ash, soot, dust, and dirt will turn grimy in humid conditions, effectively increasing the chances of a  rust problem. Also, soot residue corrodes metal, so a rusty pellet stove may suffer from compounding damage.

3. Use a Pellet Stove Vacuum To Eliminate Ash and Soot

Ideally, you should not use a regular household vacuum cleaner to eliminate the ash and soot from your pellet stove. You need a stove or ash vacuum cleaner

A regular vacuum cleaner has many plastic parts that cannot endure high heat. On the other hand, a stove vacuum has more metal parts that can withstand heat and hot ash. 

Even if you let a pellet stove cool for hours, there could be some hot spots. Besides, ash dust is a threat to a typical vacuum.

Unlike typical household dirt, ash dust is finer, and the standard filters on regular vacuums may not trap them effectively. Thus, fine ash dust may pervade the motor, and your standard vacuum will demand a costly repair or replacement.

Therefore, you should invest in a pellet stove vacuum to collect all the loose ash and soot (and other remains) in the appliance after you have used the vent brush to clean the exhaust pipe. 

4. Cover the Outdoor Cap of the Flue, Exhaust, or Chimney

After you clean the pellet stove, including the flue, next is to cover the outdoor cap of the exhaust pipe or chimney. The cover will prevent moisture from seeping into the flue and pellet stove through the outdoor exhaust vent or pipe.

You can use a plastic bag to cover the outdoor vent or pipe. However, you must ensure that the plastic or another nonporous material you choose does not have any pores or holes. Otherwise, this tactic will not be effective at moisture-proofing the exhaust system.

Also, you may use duct tape, wire, or other fastening mechanisms to set the cover, as long as the seal is airtight. This installation is not permanent because you need to remove the cover in the fall. However, your chosen cover should not be fragile, as it must endure the rain, wind, and more. 

5. Treat the Metal Parts of the Pellet Stove With WD-40

WD-40 is an effective solution to prevent a pellet stove from rusting. You should choose WD-40 EZ Reach (available on Amazon.com) if you live in a region with a moderately humid climate during the summer months or the wet season. This pack has a flexible straw for easier application. 

If you live in an extremely humid climate, I recommend WD-40 Specialist Corrosion Inhibitor if your house is in an extremely humid region. Also, some pellet stoves may be in rooms that can be more humid than others. Hence, the long-term corrosion inhibitor is an effective way to prevent rust for 2 years indoors.

The WD-40 Specialist Corrosion Inhibitor creates a coating over your pellet stove, forming a much-needed barrier between the metal and the ambient moisture in the air. 

The WD-40 products work well on both standalone pellet stoves and firebox inserts. Of course, an insert has fewer exposed metal parts. Thus, you may not have as much of a rust problem as with standalone pellet stoves. 

However, both variants need protection against rust. Besides, you should also keep the internal components of a pellet stove from rusting. WD-40 is extensively used on innumerable gears, automobile parts, and even rockets. So, you can safely use them on and in your pellet stoves. 

6. Consider Moisture-Absorbing or Rust-Inhibiting Products

You may contemplate rust-inhibiting products if you suspect the room or your house will be too humid for the pellet stove to be immune to rusting. Generally, WD-40 should offer the protection your pellet stove needs. However, you can also consider moisture absorbers and the like. 

For example, the Sunny Home Moisture Absorber is a dehumidifier, odor eliminator, and deodorizer.

These moisture absorbers are made for bathrooms and kitchens. Thus, you can place one in a pellet stove to absorb any moisture buildup inside the appliance. 

Each Sunny Home unit can absorb moisture for around 3 months in your pellet stove. So, you can time its use during the most humid months. 

Another bestselling rust-inhibiting product is the DampRid Moisture Absorber with Activated Charcoal.

These containers are made for recreational vehicles and boats. So, you can rest assured that each unit will be effective in neutralizing the typical humidity in a room or stove. 

DampRid can absorb moisture for 2 months, which is one less than Sunny Home. However, both are highly rated rust inhibitors among regular users. Besides, the evident impact of these products depends on the specific humidity, temperature, and ambient factors in a place. 

7. Remove Existing Rust and Use High-Heat Spray Paint 

The easiest and most popular rust-prevention method used for metals is painting. Of course, I exclude metalworks that are galvanized, powder-coated, etc. 

Unfortunately, you cannot use regular paint on a pellet stove. Fortunately, there is no scarcity of high-heat or temperature-resistant paints specifically made for pellet stoves, grills, etc. 

However, before using high-heat spray paints, you should consider removing any existing rust on the pellet stove. 

You may use a combination of a wire brush, sandpaper, and scrub pad to remove as much rust as you can. Also, you can get a primer, i.e., paint-prep or rust-off, to restore the pellet stove’s rusted exterior.   

WD-40 Specialist Rust Remover Soak is a popular product used to neutralize rusting on various gears, metal parts, etc. You can apply such a solution to the rusted parts of your pellet stove and let the remover work for a few hours or overnight to dissolve the rust.

This soaking solution eliminates the need for scrubbing, scraping, and chipping. The product is free from toxins, and the formula is biodegradable. You can remove rust from a cast iron pellet stove almost effortlessly using this WD-40. If any loose rust remains, simply dust it off the metal. 

Also, you may check out the Rust-Oleum Rust Reformer (available on Amazon.com). This product converts rusted parts into a paintable surface and serves as a rust inhibitor. You don’t have to sand the cast iron on your pellet stove if you use Rust-Oleum. Plus, you can use high-heat paint for a flawless finish. 

If you need temperature-resistant paint, one of the best options is Krylon High Heat Max (available on Amazon.com). This black spray paint offers a glossy finish with a temperature resistance of up to 1,200°F (~650°C). Also, Krylon is rust-resistant. Thus, a pellet stove gets multifaceted protection against rust.

8. Use a Dehumidifier When the Relative Humidity Spikes

Suppose you take one or several precautions among the solutions I have laid out until now. Yet, you worry that the humidity in your house or a particular room may be excessive for any failsafe approach to be fully effective in reality. In such a scenario, use a dehumidifier when necessary. 

9. Clean and Maintain the Pellet Stove per the Manual

Finally, clean and maintain a pellet stove, not only at the end of the season but also when using the appliance. Using a pellet stove regularly reduces the possibility of rust buildup. However, a poorly maintained pellet stove may be more vulnerable to rust and corrosion when not in use. 

Refer to the manufacturer’s guidelines in the manual for timely cleaning and maintenance. 

For instance, Harman recommends cleaning its XXV pellet stove once per 1 ton of pellets or 50 bags. This cleaning routine should be more frequent if the pellets used for the stove have a high ash content. Following such instructions help sustain the efficiency & durability of pellet stoves.  

Likewise, always keep the pellets dry, irrespective of their quality. Having moist pellets stocked in a hopper when a pellet stove is not in use will increase the appliance’s susceptibility to rust.  

Key Takeaways

A multipronged strategy is more effective at keeping a pellet stove from rusting. Therefore:

  • Clean everything inside and outside the pellet stove when it is not in use.
  • Seal the pellet stove ecosystem, i.e., viewing glass door, exhaust vent, ash drawer, etc.
  • Use rust-inhibitors, moisture-absorbers, and other preventative coatings, like paint.
  • Remove existing rust and restore the pellet stove before the precautionary measures.