Pellets Sticking to the Hopper?

It’s a common problem, pellets sticking to the hopper. Your pellet heater goes out but the hopper is full. Depending on your pellet heater model, you’ll probably also see the E1 Code, fire went out, displayed on the control panel. However, a quick look in the hopper and it’s clearly not empty. It’s easy to see there are plenty of pellets in the hopper but the problem is they are stuck to the walls. They aren’t sliding down to the auger, which is why the fire goes out. The problem is caused by the distribution of pellets in the hopper. Basically, there’s not enough weight to push pellets down and they end up sticking to the side of the hopper.

pellets sticking to the hopper

Here’s what you can do to stop pellets sticking to your hopper walls. Read on below to learn more about each:

  • Keep the hopper full
  • Clean the hopper walls
  • Wax the hopper walls
  • Apply cooking spray to the walls
  • Apply graphite powder to the walls
  • Apply aluminium duct tape to the walls

What Causes Pellets to Stick?

So what causes pellets sticking to the hopper walls? It’s because there aren’t enough pellets in the hopper with sufficient weight pushing down. As the auger removes pellets from the hopper, a small “hole” starts to form in the centre of the hopper. This is because the auger is in the middle of the hopper and draws pellets out from there. As more and more pellets are removed from the hopper by the auger, the pellets around the side of the hopper should be drawn down towards the auger. This is when problems begin and you’ll see pellets sticking to the hopper walls when they should be sliding down towards the auger in the middle.

You can see in the picture above there are a lot of pellets sitting in the hopper. The problem is, most of those pellets are on either side of the auger. Most of the pellets directly above and on either side of the auger have already been pulled into the auger. However, the pellets are the far left and right aren’t sliding down like they should. This is what causes the fire in a pellet heater to go out despite there being plenty of pellets in the hopper. Your pellet heater sensor only knows the fire went out and most of the time this is because the hopper is empty.

How to Stop Pellets Sticking to the Hopper

The good news is there are a few tricks you can try to stop pellets sticking to the hopper walls and make them slide down towards the auger. There’s no guarantee these will work and most have come from my own experience and experience of other pellet heater owners online. You’ll see a common element below, where most of these tricks make the hopper walls “smooth” or “slippery”. So there’s a good chance you’ll have your own ideas after reading the below.

Refill the Hopper

The first thing is to keep your hopper full. The problem of pellets sticking to the hopper is caused by insufficient weight. When the hopper is full, there’s a lot of weight from pellets pushing down. This means as pellets are removed others quickly slide down due to the weight of the pellets. However, once a hopper gets below 50% full you’ll start to see pellets sticking to the hopper walls. Many owners simply refill the hopper and top it up. They’ll check their heater once every 4 hour or so and tip more pellets in if needed. This isn’t really a fix but for many it’s no big drama and part of owning a pellet heater.

Clean the Hopper

Another trick is to stop pellets sticking to the hopper is to give it a good deep clean. Empty and vacuum out the hopper then wipe the walls down. Run your finger down the inside hopper wall. Does it feel sticky? Some pellets, possibly due to how they are made, might contain resins or other ingredients that leave a little residue on the hopper walls. This makes the wall sticky and not as smooth, which prevents pellets from sliding down towards the auger. If the walls feel a little sticky, get some alcohol spray and paper towel and clean the walls. Give everything a spray and wipe down and see if the walls no longer feel sticky.

Wax the Walls

Much like the alcohol cleaning trick above, another thing to try is to add some auto wax. Again, clean the hopper, remove the pellets and vacuum out fines and everything. Wipe it down with a damp rag or paper towel. Once dry, add some auto wax to the walls. Some people have reported that adding auto wax makes the walls “slippery”. This prevents pellets from sticking as the thin coating of wax causes the pellets to slide down. I’ve never tried this myself but it may be worth a shot if you’ve tried everything else and still having problems with pellets sticking to the hopper walls.

Pam Cooking Spray

Yes, believe it or not some people have used pam cooking spray. Clean the hopper out completely and wipe it down. Next, get some pam cooking spray and spray the inside of the hopper. Just like the auto wax trick, the cooking oil spray is meant to make the walls slippery. I’d definitely gives this a try before using auto wax. Definitely start by applying a little misting to all walls and see how it goes. If pellets are still sticking, add a bit more. It definitely won’t cause or do any damage to your heater provide you are only spraying small amounts in.

Apply Graphite Power

Similar to above, try adding a little graphite power. Graphite power will work in the same was as the pam cooking spray and auto wax. Clean the hopper out thoroughly and rub graphite power on the walls. Don’t over apply it, considering how much graphite power costs, and just add enough so the walls become smooth and slippery. As with the wax and cooking spray trick, don’t over do it. Try a little first and if no luck add a little more and try again.

Aluminum Duct Tape

Lastly, and in similar fashion to the tricks above, some people have reported that applying aluminium or metal duct tape to the hopper walls helps with pellets sticking to the hopper. The slippery or smooth surface of the duct tape helps prevents wood pellets sticking and encourages them to slide down towards the hopper. Clean the hopper out entirely and remove any fines then apply metal duct tape to the lower half of the hopper where the pellets stick. Make sure it is applied evenly. I’d definitely try the tricks above before doing this as removing the tape will probably leave a sticky residue on the hopper.

Do Some Pellet Heater Brands Not Have This Problem?

It doesn’t matter what brand pellet heater you have. All brands of pellet heaters from more expensive European models like Piazzetta and Palazzetti pellet heaters to generic made in China heaters. The steeper the hopper walls the less likely you will have this problem. If this is a concern of yours, it doesn’t and has never been a problem for me, then when you go to buy a pellet heater, regardless of model, check the hopper walls. The steeper the walls the less of a chance you’ll have to worry about pellets sticking.

Are Some Pellet Brands Better Than Others?

Again, no. It doesn’t matter if you buy wood pellets that cost $25 a bag or if you are lucky and can buy wood pellets in Tasmania for $8.50 a bag. All pellets, no matter than brand, may stick to the side of your hopper walls. As I’ve mentioned above the cause is due to how most pellet heaters operate. It has nothing to do with pellets, what they cost or their quality.

Pellets Sticking to Hopper Summary

Pellets stick to the walls of the hopper because there’s not enough mass pushing the pellets down. It usually occurs when a hopper is less than 50% full. The simplest way to fix this is always keep your hopper topped up and full of pellets. Otherwise, I’d empty the hopper out and give it a good clean with alcohol. Do this when you do your yearly pellet heater deep clean. If it’s a major problem, then some people have reported cooking oil, graphite power and auto wax works. All of these tricks aim to make the hopper walls smooth and slipper so pellets stop sticking to them.

Pellets stop flowing into auger