Learn all the maintenance tips and tricks that your outdoor wood boilers need to be in great shape! Find out all about the products, boiler treatments, and scale inhibitors you can use for different types of boilers. Additionally, you'll find out how experts respond to the most frequently asked questions from users on wood boiler installation and maintenance.

Regular Maintenance - Do It Yourself Tips

Filling with Water:

Connect your domestic water to the return line to the furnace using a ball valve. This makes it much easier to fill and flush the unit. Start filling the unit inspect for leaks. Make sure the ball valves on the unit are open to the return and supply. Once the green light on the control panel goes on, you’re full. Or if is simple over flows. Don’t worry this is not a problem.

Flushing your Furnace:

It is very important to drain and flush your furnace each spring. To drain furnace — open drain valve and let stove empty completely. To flush — leave drain valve open and close pump valve. Add water to furnace through the return lines. Let flush for several minutes. Close drain valve and open pump valve. Refill stove and add boiler treatment right away.

Adding Boiler Treatment:

This should be done every year! Allow system to burn for 2 hours and then add boiler treatment as follows. Before adding boiler treatment, be sure that the water temperature is at least 100 degrees or higher. Add the boiler treatment that came with your unit or purchased from your dealer. Add the treatment to vent (Small tube) on top of the unit.

This should be done every year! Allow system to burn for 2 hours and then add boiler treatment as follows. Before adding boiler treatment, be sure that the water temperature is at least 100 degrees or higher. Add the boiler treatment that came with your unit or purchased from your dealer. Add the treatment to vent (Small tube) on top of the unit.

Annual WoodMaster Maintenance:

Protect your fire chamber by placing the chimney cap over the chimney during the off season, inspect all silicon caulking and make sure it has a good seal so moisture can’t enter furnace. If you have an ash auger, remove it, clean out all the ashes and scrape excess creosote from the fire chamber surface. Reinstall the ash auger. Moisture combined with ashes will eat through metal in a short time.

Bleeding the Unit:

Routinely pay attention to the water level light. If the light is not lit, this indicates water level is low and the furnace may need to have water added. Add water until it over flows the vent pipe on top of the unit. Not a bad idea to check to make sure the light is working properly. Open ball valve in back to see if the light goes out or check the over flow pipe with a flash light. The circulation pump will be very helpful in bleeding the air out. It can take several minutes to do this.

Firing the Unit:

Once you have determined that there are no leaks and all looks good. Paper and kindling should be used for starting the fire. Build a small fire, and add wood as needed. Be sure pumps are circulating when firing the furnace. You might notice some water on the inside walls of the unit, this is normal the furnace is sweating like a cold drink on a summer day. Once the furnace has reached 180 degrees, the furnace is ready to be filled to capacity. I recommend burning cut, split, seasoned wood. Do not overfill the unit so hot coals fall out when opening the door. The best is a well-controlled fire and when the wood gets low, rake the ashes exposing buried unburned coals. You will be surprised those coals will heat your home all day and then some.

Ash Removal, Rotation, and Disposal:

Maintain a good ash rotation. This should be done weekly. Remove ashes when the furnace is very low on wood. If your furnace is not equipped with an ash auger system use a shovel to take ashes from the front of the firebox and use a rake to pull ashes from the rear of the furnace to create a level bed of hot coals. Tip Ashes are great for the garden. Ashes should be placed in a metal container with a tight-fitting lid. The closed container of ashes should be placed on a noncombustible floor or the ground, well away from all combustible materials, pending final disposal. Ashes should be retained in the closed container until all cinders have thoroughly cooled. At least 48 hours. (coals can live for a week or so) Keep this in mind when disposing ash and coals. Forest fires!

Creosote Information and the Need for Removal:

When wood is burned slowly, it produces tar and other organic vapors, which combine with expelled moisture to form creosote. The creosote vapors condense in the relatively cool chimney flue of a slow burning fire. As a result, creosote residue accumulates on the lining. When ignited this creosote makes an extremely hot fire. The chimney connector and chimney should be inspected at least monthly during the heating season to determine if a creosote build up has occurred. If creosote has accumulated it should be removed to reduce the risk of a chimney fire. This is another reason why an outdoor Wood Master furnace is the superior solution to heating your home.

Boiler Maintenance Kits - Description and Costs

CorQuest - WoodMaster

The CorQuest product from WoodMaster is an excellent product, it is a nitrate-based product. It works very well for what it does, it is an anti-rust and scale-inhibitor.

ProTech 300

We also make our own product, which is a little less expensive, and it is also a nitrate-based product. It is called the ProTech 300.




It also treats 300 gallons, and if you use this product inside of WoodMaster, or any other brands, there's no way for them to tell if it's their product or ours.

So, rest assured that you can use both of them.

The ProTech 300 sells for about $34.95. If you buy four or more, you can get 'em down to $29.95.

The WoodMaster product is up to about $40 from WoodMaster, Central Boiler's about $60, Pro-Fab's about $80, and a lot of different manufacturers, they range from the ballpark of anywhere from $50 to $120 dollars.

But they cannot tell if they're using the ProTech 300.

Boiler Maintenance Test Kits

We also sell the ProTech 300 Test Kit. This gives you about 15 to 20 tests, and it allows you to keep it for about three, four years. If you don't want to bother with testing, a simple solution is you just use the ProTech, and you change it out every year. The shelf life of the ProTech is about two years in the unit, but it starts to degrade, and also, with the evaporation of these units, it'll also start to drop off.

If you buy extra ProTech, you can leave it on your shelf for up to five years.




On the A-200 product, this is also good for two years, however, we do recommend changing it yearly, just like the ProTech. It ensures that you're getting the protective measures in which you need inside your boiler.

The A-200 also comes with a test kit with 15 to 20 test kits, but again, if you simply change your fluid once a year, there's no reason for the test kit, save your money there. Test kit's about the same price as the quart of A-200.

Maintenance Products for Different Types of Boiler

These, also, two units, two boiler treatments, and scale inhibitors, also are designed to work with stainless steel, or mild steel, whichever your product's made of. Boilerplate or any other products, this is what all the boilers need.

Wood Boilers Q & A

Is Stainless Steel better?

Here at Alternative Heating & Supplies, we offer both options Stainless or Mild Steel. Well, you hear a lot of good points from both sides. I personally purchased the mild steel unit. The warranties are usually about the same and I simply look at it this way. If my mild steel unit lasts 20 to 25 years the unit paid for it self over 10 times. Stainless Steel is also made from different metals which shrink and expand differently causing hairline fractures. For the additional cost of about $1400 I personally don’t see the value. Also, ask a welder “what welds Better mild steel or stainless steel?” Mild steel welds better!

Is Dual Fuel Important?

Your outdoor wood furnace is designed to be incorporated into an existing indoor heating system such as a hot water boiler, radiant heat, domestic hot water and forced air furnace. If your wood furnace is hooked up correctly, your existing indoor furnace will act as your back up to your wood furnace. Don’t worry, your indoor furnace will also prevent the wood furnace from freezing while you are on vacation. We recommend an indoor furnace for a couple simple reasons 1. for resell reasons and most home owners insurances require it. 2. wood furnaces are designed to burn a solid (Wood) fuel they are very very inefficient burning a liquid (Oil) fuel.

How Far Away Can the Outdoor Wood Boiler Be Installed?

The Outdoor wood furnace has the ability to be 3 to 300 feet away from your home. Couple things to keep in mind. You will need to visit your wood furnace once a day. You will need to have easy access to this location truck or tractor to replenish the wood when needed.

How Much Wood Will I Use?

Well, that depends on your home, insulation and the quality of wood you’re burning. This might help! 2,500 sq home well insulated with good wood will go through 5 to 7 cords a cold session (6 months) That is heating the home and a domestic hot water 60-gallon tank.

The cost of a cord these days is $120. You can see the savings if you buy. That is $600 to $840 a year to heat your home naturally. What did you spend last year? Imagine if you get your own!!!

Outdoor Wood Boiler Maintenance on Vacation

What happens with my wood boiler when I go away for a couple days?

This is one of the most common questions that I get. You have several options depending on your situations.

If your wood furnace is hooked up correctly your existing indoor furnace will back heat the wood furnace preventing it from freezing! The cost of your indoor furnace back heating your outdoor is very minimum cost everything is very well insulated.

Couple more options for you:

  • You can let the fire die down and drain the furnace. This is what I do it only takes about 10 minutes to drain the unit. When I return I refill the unit and relight the fire.
  • You can set up your unit with a bypass to not heat the home and circulate within itself the burn time will be much much longer 4 to 5 days.
  • If the weather isn’t really cold the circulation pump is moving the water quite quickly. Moving water is hard to freeze.
  • Maybe a friend or family member could help and feed the unit while you're away.
  • You could look into anti freeze. Keep in mind most anti freeze is terrible to our environment. please dispose of properly!

What If the Electricity Goes Out?

This is another commonly asked question. The outdoor wood furnace uses very little electricity which can be supported by a small generator. What I actually did is I ran a regular inexpensive extension cord to my unit and that is how my unit is wired. So all I need to do is unplug from the wall and plug into a small generator. Problem solved.

Some people ask well if you don’t have a generator you have no heat. That is correct! Most homes lose electricity they have no heat either. Either way, you will need something to back up your existing home as well as the wood furnace. I know several people including myself are looking into solar and wind options. These wood furnaces use very little electricity. As soon as I get off the grid I will let you know.

How long will a wood furnace last?

Well, this is like asking how long will my car will last. The simple truth is that we have a 10-year warranty. which has excellent coverage. These units should last 20 to 25 years or more if they are used and maintained properly. The oldest outdoor wood furnace I have seen is 14 years old with no visual wear on it and running strong. Wood Master wood furnaces should last longer than most units simply because they have superior construction and more importantly a superior design.

The design is the most important issue here. If you ask a plumber they will tell you that what kills boilers (Outdoor wood furnace is basically a boiler) is sediment build-up which rots the boiler inside out. With our design, we use a round drum where sediment can not build up and we have a drain at the bottom to flush the unit out yearly.

Some units have a square water chamber, “water baffles”, zig zag tops to help heat transfer which will catch all the sediment. These units have no way to flush the system as well. They try to solve the problem with chemicals and in line filters which you can add to your bill. I know this because I have owned a one since 2002. I still own it and I had to move it over to the warehouse in which I store my wood master parts and supplies. I can no longer run it in my home because of a neighbor who lives 700 feet away complaining about the smoke.

What Makes Wood Master the Best Heating Solution?

This is similar to when a young person that joins a company that raises all these ideas how to do everything better way than the way you have been doing it for years. Simple; there is a good reason why it has been done this way for years. What I’m getting to is that this is what has been done with a couple other wood furnace companies. I will describe them below for you and you make your decision which makes more sense.

1. The zig zag feature which helps heat more water; good idea except that is where all the sediment will build up and start to rot the furnace out from the inside and not forget the additional welding (as discussed in How long will a wood furnace last) There is no way to clean the inside of these units.

2. If you look at the door location and the Heat Collection area This air is 1500 degrees; another good idea until you have to open the door. The heat baffle is lower than the top of the door. That is where you are standing and when you have to put a big log in and you are displacing several cubic feet of 1500 degree air; where is that going? You got it in your face. I have lost many eye brows and facial hair and had to listen to my wife laughing at me. I know first hand I owned one for several years and still show mine to customers. (side by side comparison)

3. Natural draft is a bad idea: These units are known to smoke a lot due to their natural draft. To give you an idea it is like throwing a match onto a leaf pile, how much will it smoke? Your right a lot! Now if you do the same thing and then blow on it, what happens then? The fire starts and gets hot faster and a considerably less smoke. As you can see this is not rocket science, these ideas were good ideas but not practical, similar to that young kid on the job tell the experience guy better ways of doing something.

4. With a Wood Master, we use a round drum which will not collect sediment and can be easily flushed to prevent rotting from the inside out.

5. We use a fan on the front of our unit to burn hotter to reduce smoke and higher efficiency.

6. With using a round drum you have 50% fewer welds.

7. We have smoke release area so you are not eating smoke or hot 1500 degree air while filling the unit with wood. This is an eye brow saver!!!

8. Did I mention we cost about $1,800 less than the equal size competitive unit? Heads up they will say their smaller is equal to ours to try to prices closer. The truth is very easy to figure out. How many cubic feet in fire barrel will tell you which goes with which? Don’t listen to BTU ratings! This is a very dumb statement, what kind of wood are you burning? Green, seasoned, wet, rotten, Oak. Pine, way too many variables to mention. Fossil fuels can do this because there is a constant fuel source. Example Oil burns at about 2000 degrees and propane around 1400 degrees we can give a BTU rating with this NOT WOOD!

9. Our wood furnaces are on legs and don’t use a full skirt for a couple reasons. First, if it is warm and dry rodents will find a new home in all that great polyurethane insulation which is excellent to dig in and hard to fix! Again this is experience talking. (Field mice had babies, they are so cute! But not in my furnace) Secondly, with the full skirt, they suggest a concrete slab. This now makes your furnace a permanent structure in most towns and you will need permits and it is now taxable!!! I love taxes!!!

10. Did I mention that our furnace is $1800 less!

Final Note! Very Important! Ask to read their 25-year Warranty!! You might feel like a deer in headlights! Basically, I will sum it up for you quickly. There is a 10 year prorated warranty on the fire barrel and only 1 year on the electronics. (My Control panel blew at a cost of $166.00 after 2 years). ARE YOU READY FOR THIS? The 25-year warranty is on Manufactures defects! If some know what this covers please let me know. (Blemish in the paint or what?) Just another game. I learned this the hard way and all I want to do is recommend all the other brands before this one. Please don’t make a Classic Mistake like me!!!!

Can You Put Antifreeze in Your Unit?

Yes, you can, however, it might get pricey. There are a couple alternatives that might help you with this topic.

1. If you’re going away just empty your unit and lines; this is very simple. Refill and restart your fire it takes about 4 to 6 hours to get back up to temperature.

2. If you have a boiler in your house and using a plate exchanger to heat your boiler this will also back-heat. What that means if your unit temperature drops your, existing boiler will kick on to provide heat to your home, it will also heat the water in the boiler and prevent freeze up. Yes, you will be using more fuel to heat your home and the outside wood furnace.

3. You can also set up a by-pass. What I mean here is you setup a by bass from the outdoor furnace from heat the house and send the water right back to the unit. So the unit is only heating itself which will last for days maybe week or weeks depending on temperature and weather conditions.

Where Do You Get the Wood From?

Try phrasing it like this: where can’t you get good! Wood can be found easily. For example, tree companies have to pay to dump wood in landfills and other locations. They most likely drop off the better hard woods, but we don’t care we can burn all wood. Most tree guys can’t sell certain types of wood (soft wood like pine, hemlock) so they have to pay to get rid of it or drop it off to you free of charge. Once you build a relationship with a couple tree guys you will be home free.

Also look around it is all over the place. Free Pallets all over the place. I never heard a neighbor say no to allowing you to go in cleaning up downed trees and branches on their property.

You can also call tree companies a ask them to cut the wood into 26-inch lengths and don’t have to split it-what will the cost be? Also mention to them to bring the wood they can’t sell to other customers such as V’s of the tree, Big Knots, and all those weird shaped pieces. They should deliver it to you with a smile at half the cost. In CT it should cost about $150 to $175 a cord delivered, You should get it for $75 a cord delivered.

Can you burn coal?

No, we don’t suggest it. The whole reason for buying an outdoor wood furnace is not to buy a fossil fuel and or burn fossil fuel. Your home already has the capability of burning fossil fuel.

To find out more about Outdoor Wood Boilers parts and accessories and, feel free to subscribe, and I will keep the videos coming.