Pellet stove maintenance

Pellet stoves are easier to maintain than wood stoves but need to be cleaned regularly for safe, efficient performance.

FAIRBANKS —  Q: What type of maintenance does a pellet stove need?

A: Are you thinking of purchasing a pellet stove or boiler? Pellet appliances have some advantages over their cordwood-burning counterparts — including less maintenance, as pellets produce less ash and particulates than cordwood. 

However, you still have to clean a pellet stove or boiler. A clean stove is more efficient than a dirty one, because it will allow more air flow and the heat exchanger will transfer heat more efficiently. Also, a clean stove will last longer because the components will wear down more slowly. Finally, clean stoves are safe stoves, as removing buildup helps to prevent chimney fires.

Each pellet-burning appliance will come with an owner’s manual that explains a cleaning procedure and recommended maintenance schedule. In general, though, cleaning a pellet-burning appliance is similar to cleaning a wood stove. If done regularly, it shouldn’t take more than 15 minutes. Before cleaning your stove, remember to turn it off and let it cool down.

First, remove the ash from the burn chamber and ash pan. Some stoves will also have an ash trap located in the exhaust. You can use a small shovel or an ash vacuum. Avoid using your household vacuum because ash and soot can ruin it.

Next, scrape the soot off of the burn pot and heat exchangers. The heat exchangers are usually a series of tubes in the firebox the hot air passes over. You can use a wire brush to scrape any soot off of them. If you see any “clinkers,” or hardened deposits, make sure to remove them. Clinkers are formed from melted ash that then hardens and can block air pathways. While you do this, glance at the pipes and ensure they are clean so they facilitate good airflow. If they are getting dirty, it’s time for a service. It’s a good time to check the hopper and auger, too, to make sure there are plenty of pellets and no blockages.

Finally, if your appliance has a glass door to the burn pot, clean the glass with a commercial glass cleaner. This will allow you to see the flame when the stove is burning; it should be bright yellow or white. A darker orange flame means it’s time to schedule a service.

Many users clean their stoves each time the ash pan is full. This will depend on both how often you use the stove and the grade of your pellets. Premium-grade pellets have a lower ash content than standard or utility-grade pellets, so you don’t have to clean the stove as often.

In addition to cleaning, there are two other maintenance tasks: cleaning the auger tube and hopper and scheduling a service of the appliance.

Occasionally, when the auger tube and fuel hopper are empty, vacuum the sawdust so it doesn’t build up and block the feed system. At the end of the heating season, remove pellets from the stove, auger or hopper so they don’t collect moisture and rust. They might also settle down over the season and stick to the bottom or sides of the container.

Servicing a pellet appliance is typically done annually just before the heating season. A heating professional will thoroughly clean the entire appliance, including the pipes. They will also inspect seals, lubricate any moving parts, and perform diagnostic tests to ensure the stove is working properly. They may adjust the controls to ensure the stove is operating efficiently. If the appliance is used a lot, service may be required more than once a year. To know when to schedule the service, it can be helpful to track the amount of pellets that are burned between services for your stove (one ton? two tons?) and use that weight to estimate when the next appointment should be.

At CCHRC’s Research and Testing Facility located off Geist Road, we use both a masonry heater and pellet-burning boiler to heat the building. Our masonry stove burns cordwood to heat the front part of the building and a pellet boiler serves as the back-up heating appliance for the building addition. Join us for a public building tour at 2 p.m. on the second Thursday of each month to see and learn about these and other heating appliances in the building, or feel free to contact us with any questions on heating! (info@cchrc.org, 457-3454)

The “Ask a Builder” series is dedicated to answering some of the many questions Fairbanks residents have about building, energy and the many other parts of home life.

Ask a Builder articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, contact us at info@cchrc.org or 457-3454.