Hearth News

Learn Helpful Tips & Tricks from the Community

Obtaining Domestic Hot Water from a Wood or Coal Stove

Many folks have expressed a desire to obtain hot water from their stoves. First, I should mention that this article refers to Domestic Hot Water, meaning the water that is used to wash dishes, take showers, etc. A woodstove cannot produce the volumes of water needed to heat your home through a baseboard or radiator system. If you are looking to heat your entire home AND produce your Domestic Hot Water, take a look at some of the wood burning central heating systems. These produce your hot water AND heat your home!

There are two different types of heat exchangers which can be fitted to stoves and used to heat your domestic water.

1. External Heat exchangers - if the stove has a large flat surface on the rear, then a serpentine can be fabricated that goes against the rear. If it is enclosed with a layer of sheet metal behind this coil, it will provide better heat. I’ve had them custom made..but the same shops that make DHW coils (tankless heater) for hot water boilers. These coils were made from a finned copper (usually 3/4”), so much the better for heat exchange. You could make your own by using 180 degree copper bends, but use high-temp (silver) solder so the coils don’t come apart if they ever hit a very high temperature.This would only happen if they ran out of water and the stove was VERY hot. Input would be into the bottom of the coil, and output from the top. A pressure relief valve should be installed next to the coil…WITH NO VALVES BETWEEN THIS PRESSURE RELIEF VALVE AND THE COIL.

2. Internal Heat Exchangers - A few companies make such an item, although it may not be easy to find. The best ones are small tanks or coils made of stainless steel. The kits come with instructions and a pressure relief valve. In order to install an internal heat exchanger, a hole must be drilled into the stove body. This may be a job for a professional, as you don’t want to compromise the safety or integrity of your...
Coal can be a viable option for those folks who live within a few hours drive of Pennsylvania’s Anthracite (hard coal) mines. This hard coal is packed with an enormous amount of energy. Coal stoves usually can burn longer on each fuel load than woodstoves and they provide a more even and controllable heat. Coal is also “American Made.”

Pennsylvania Anthracite coal is very clean burning and produces no visible smoke or creosote. However, the mining of coal can produce some negative effects on the environment. Coal is not renewable (at least not without waiting a few million years).

Coal is most efficient when burned in freestanding stoves. Some stoves are “dual-fuel” and capable of burning both wood and coal. Coal fires are difficult to start, but once alight a fire can last for weeks or even months. For this reason, coal is best suited to those who use their stoves on a full-time basis.

Maintenance—Coal Stoves—Coal stoves produce no creosote or tar, and the chimney and smoke pipe will usually only contain a white or brown fine ash coating. It is important to clean the coal stove, smoke pipe and chimney immediately following the burning season as this ash can be quite corrosive when combined with the heat and humidity of the spring and summer.

How Long will they last? A quality coal stove could easily last ten years or more. Coal burns much hotter than wood, so it should be common to replace coal grates and liners as time passes.
by Ken Rajesky, Hearth Industry expert

Proper Wood Stove, Fireplace, and Gas Stove Glass Door Cleaning

Before you start any procedure involving your glass door, its important to fist check your manufacturers instructions to ensure that the cleaner or the method that you plan to use complies with their requirements. This is especially important if the glass is still under warranty. Second, always make sure that you have the proper safety equipment such as gloves or glasses. Cleaners may be caustic to your skin, and your eyes are irreplaceable.

There are two ways to clean your glass. The first way is to clean the glass with the glass still attached to the door. I recommend using a cleaner specifically designed for removing the brown and black stains (carbon) from the glass. Cleaners such as Glass Plus do not do a good job when it comes to carbon. There are several brands available, and the cleaner I have had great success comes in the form of an aqua colored paste. Typically the cleaner will come in a 12 oz. Bottle, and say Fireplace Glass Door Cleaner or Woodstove Glass Cleaner. You must clean the glass while its cool for best results. All youll need is a few paper towels, or cloths.

Leaving the Glass in the Door

1. Open the door(s), and if possible, remove the door for easier access to the glass. If access is easy while the door is still attached, then leave it on.

2. Apply an amount of cleaner about the size of a 50-cent piece onto the paper towel.

3. Rub the paste onto the glass in an elliptical pattern. Be sure to clean the edges and corners.

4. Allow the cleaner to dry for a few seconds, and then rub off the paste and carbon with a clean cloth.

5. If carbon still remains in a few spots, repeat steps 2-4.

Removing the Glass to Clean

yV4gqxekjkLcmmwoj8ksrMBbCU6oIGYMyHqWleGGBE2THWqfvoA2inQl9GGV4hJUEIPc8MSO40aMDe14LdFyS119sEoQ75Uh.jpg

If you need to remove the glass to clean, and/or you feel you need to replace the glass gasket, then you follow the steps outlined below. If you have a digital or...
Central Heat with Coal

Coal Stoker Fire (efm)

Hard coal (anthracite) can be an economical fuel and is in ready supply within a couple hundred miles of the Pennsylvania Coal fields. For some reading on space heating coal stoves, see this article. Check out our Fuel Comparison Calculator to compare the cost of Anthracite coal to other home heating options.

Coal is well suited to central heat because of the long burn times, clean burn characteristics and the ability to easily burn at a range of outputs. As with other central heating equipment, coal units are available for Hot Water (boiler) and Hot Air (furnaces). Note that a boiler can be tied into a hot air system using a fan coil, but a furnace cannot be tied into a boiler system.

Types of Systems

Coal central heaters are available in hand-fed or stoker models.

wWgYBXWmNWtmL2nToJQmk8ntSObjnb8ZqO1gn1EFbqn3KRRoemMuID8W_p4dwGv5hST2FBqMtwcc1_8wb-x_uDR_NFdUMxTD.jpg

EFM Coal Stoker Furnace

A hand fed (also called batch fed) unit is similar to a freestanding coal stove, where the operator loads the coal into the unit using a shovel or coal bucket. The coal burns in one large mass - usually using the natural draft of the chimney, and the heat is exchanged into your existing distribution system. Hand fed models will usually use “nut” coal or larger. These larger sizes allow for air to easily come up through the large batch of coal. A typical mid-size hand fed unit will hold 70 pounds of coal, and require approx 2 feedings every 24 hours (12 hour burn time).

A Coal Stoker is a automatic system, using a screw auger to feed very small coal (rice size) into a burn pot. The stoker can be fed from a large bin holding many tons of coal. Most stokers on the market today are boilers (water based), although a few companies (EFM) produce hot air models.

Shopping for a Coal Central System

Make certain that the...
Coal fires are not as easy to start as wood fires and the ease of burning will vary with different types and makes of stoves. The burning of coal requires patience and a specific and regular procedure of loading, shaking, adjusting, etc. If you do not follow the right procedure the coal fire will go out. This can happen in a short period of time and once the extinction process has begun, it is almost impossible to reverse.

In this article:

Starting a Coal Fire

Additional Tips on Starting

Raking and Shaking your Stove

Maintenance

Safety First

STARTING A COAL FIRE

1. Use paper and dry kindling to start the fire.

2. Add small pieces of hardwood when fire is burning hot. Keep the draft control fully open till a hot fire is established.

3. When a decent bed of red wood embers is built up, start adding coal—small amounts at a time. Keep the draft control open!!

4. Continue adding small amounts of coal until there is a 1” to 2” bed of burning coal. Don’t add too much coal at one time and allow sufficient time between each small loading for the coal in the stove to thoroughly ignite.

5. It is important at this point to fill the stove to the highest level possible. A deep bed of coal is critical for the proper function of all coal stoves. Since coal can be regulated better than wood, a deep bed does not mean that you can only run the stove hot - rather you can control the stove by setting the air control on your stove.

6. After all the coal has been ignited and is burning with a blue flame, then the draft control can be turned down. Serious damage can result if the stove is run wide open for extended periods of time. Make sure that the ash pan door is closed at all times.

CAUTION—DON’T ATTEMPT TO START COAL FIRES UNTIL THE TEMPERATURE OUTSIDE FALLS BELOW 55 DEGREES ON A 24 HOUR A DAY BASIS-YOUR CHIMNEY WILL NOT DEVELOP ENOUGH DRAFT UNLESS OUTSIDE TEMPERATURES ARE BELOW THIS.

ADDITIONAL HINTS ON STARTING

1. Some users have...
Understanding hopper-fed coal stoves (Gravity type)

Many European and some American coal stoves use a hopper to hold coal that is to be fed onto the fire. Some popular brands that use this design are: Surdiac Efel Franco-Belge Certain Vermont Castings Vigilant Models

Surdiac Stove w/Hopper

Although many of the same tips mentioned in our coaltips article apply, it is also important to have an understanding of the way these products work.

The drawing on the left shows an inside view of a typical hopper-fed coal stove. Coal is loaded into the top of the stove and, once the stove is going well, should be kept full or nearly full. Because of the air flow design only the coal in the lower part of the firebox will burn.When this coal burns completely and turns to ash, new coal will take its place, helped along by your raking/shaking of the grates.

(efel type shown in cutaway. Surdiac and Vermont Castings use a center-fed hopper - operation is similar)

The temperature of these stoves is usually controlled by a thermostat with either a bulb-type or bimetallic element. European Coal Stoves often use a thermobulb connected to a control knob. The dial opens the draft inlet (higher number is more open)- and then when the stove gets hot- the thermobulb closes and opens the inlet to even out the effect of the fire. The bimetal thermostats function in much the same fashion, but not as accurately.

ovbq2xUJbqygs8gPg4My4voVSPgBMnG3KuYXT3G-y9UdN5brS1s2BjfppIE-GRRvr5owVnyBkEdH1sjHikck-NfvGXpvi7vr.gif

Hopper-Fed Cutaway

Fuel and Hopper settings - Most of these stoves are designed to use pea (smaller) coal, which tends to flow onto the grates easier. Inspect your stove for different hopper adjustments and experiment (middle setting is best on most).An exception is the Vermont Castings Vigilant, which uses nut sized. European coal stoves work best with a low-ash coal. Poor fuels will result in shorter burn times and less heat output. Old Company Lehigh brand anthracite coal is known for low ash content.

Chimney...
Coal Appliances COAL STOVES AND INSERTS
In certain parts of the country, coal is popular as a home heating fuel. Coal comes in different grades, the best grade for home heating being “hard coal” or anthracite, of which the best varieties are mined in Eastern Pennsylvania. Most of the coal appliances on the market are designed to burn this high grade coal, which sells for $150. to $250. per ton. Because coal is a dense and powerful fuel, and burns extremely efficient, this ton of coal can produce as much or more heat than a cord of wood and substantially more (almost twice as much) as a ton of Pellets.

Typical Coal Stove or Insert

Coal stoves are quite similar to their wood burning cousins. Most use natural draft (don’t need electric or a fan assist for combustion), and have the same chimney requirements as wood stoves. In the past, many stoves were designed to burn both coal and wood. This type of stove is rare now, as the EPA standards have forced manufacturers to “tune” their stoves for one fuel or the other.

All Coal Stoves must have grates and an ashpan or ash removal area. Coal produces 10 times as much ash per pound as wood does, so a large ashpan is a good feature. For coal to burn properly the combustion air must enter below the grates and come up through the coal bed. Most natural draft coal stove use a medium to larger size coal (Chestnut size).

Typical Coal Stove

Learning to ignite and burn anthracite coal can be frustrating and patience is surely a virtue. If you have not had previous experience, please read the document Coaltips before you attempt starting your first coal fire. This document was created after we heard the same questions hundreds of times over. If you read it carefully and follow it to the letter, you’ll be an expert in no time.

Stoker-Feed Coal Stove

Some coal stoves, both central heating and freestanding, use a stoker feed mechanism to automatically feed coal and remove the ash from the firepot. These stokers usually use a smaller...
(written by Corie Podschelne)

Perhaps you’ve been a long time wood burner and are looking for a stove that requires less tending; or maybe you’re new to solid fuel room heating completely. Burning coal, especially for a new coal user, can be particularly daunting due to difficulties in igniting a coal fire. Also, coal burning has some unfortunate (and false) stigmas surrounding it that come from a different era of coal burning. Modern coal stoves are amazingly simple to operate, extremely efficient and clean burning and require significantly less tending than a similar wood burning unit. This article will focus primarily on burning hard coal, also referred to as anthracite coal, however of the concepts will be just as useful when considering soft or bituminous coal.

-Coal Sizes

Anthracite coal comes in a variety of sizes; certain stoves require a specific size of coal whereas other stoves may be able to burn a few different coal sizes. While there are more sizes of hard coal than those listed blow, these are the primary four sizes that will be used in most coal stoves.

Rice - 3/16” to 5/16”

Pea - 9/16” - 13/16”

Chestnut - 13/16” to 1 5/8”

Stove - 1 5/8” to 2 7/16”

-Stove Types

1) Stoker

A. Introduction

A stoker stove is an automatic coal burning unit, wherein some type of stoker mechanism feeds fresh coal to a burning fire at a feed rate set by the user. Air is generally forced through the fire from the bottom by a blower or by a flue mounted draft inducer. The coal stoker stove operates on much the same principle as the pellet stove. The user must simply keep the hopper filled with coal and the ash pan empty and the coal stoker stove will run continuously.

B. Venting

Stoker stoves, depending on manufacturer, can often be “power-vented” because of the forced draft within the unit, greatly simplifying the venting system and reducing cost. In other words, many coal stokers can be direct vented much like a pellet...