Thank you and congratulations on the purchase of your new Nature’s Comfort Boiler!
With the purchase of this Nature’s Comfort boiler, you can now appreciate the high degree of
craftsmanship and reliability that are a result of every boiler being carefully hand-built. Your
choice shows the recognition you have for high quality products.
We deem it important to provide you with this operation and maintenance manual, allowing
you to use your equipment under the best possible conditions and in the most optimal
manner and furthermore to increase it’s operating life. We strongly advise you to read
through this manual carefully and keep it handy.
THIS MANUAL INCLUDES IMPORTANT SAFETY INFORMATION ON PAGE 4 & 5.
Parts and accessories for installation are available from your dealer or Nature’s Comfort.
Again, thank you for purchasing a Nature’s Comfort Boiler.
We appreciate your business!
For the most up to date installation and operation information, or if you need to
see any page in color, go to www.naturescomfortllc.com.
Please keep this manual with all other important papers. The information in this manual is
necessary for the installation, operation and proper use of your boiler. If you should ever
have a problem or question please refer to this manual or call your dealer. Please have your
serial number ready. This is found on a silver tag on the back of the rear access door or
stamped into the fire door jamb on the top left. If your dealer does not have the information
you need, request they contact Nature’s Comfort and your dealer will be further educated to
provide the best possible customer service. Please keep in mind that Nature’s Comfort built
your boiler but did not install it and has no control over the installation, the efficiency of the
building’s insulation or what is burned in the boiler.
Page 2 of 25
Table of Contents
I. General Information
A. Terminology ............................................................................. 4
B. Specifications .......................................................................... 4
C. Clearance to Combustibles .............................................. 4
D. Boiler Dimensions ................................................................. 4
E Safety Precautions .................................................................. 5
F. 20 Year Limited Warranty .................................................... 6
G. Customer Warranty Card ................................................... 7
II. Best Outdoor Boiler Burn Practices
A. Fuel Used ................................................................................... 8
B. Loading Fuel ............................................................................ 8
C. Starting a Fire ........................................................................... 8
D. Location ..................................................................................... 8
E. Wood Recommendations ................................................. 8
F. Burning Coal............................................................................. 9
G. Heating the Home ................................................................. 9
H. Heating Domestic Hot Water ........................................... 9
I. Thermostat Control............................................................... 9
J. Pex Pipe Connections ..................................................... 10
K. Insulated Pex Pipe.............................................................. 11
L. Adjusting Airflow On Draft Blower .............................. 11
III. Installing the Boiler
A. Location of Boiler ................................................................. 11
B. Concrete Block Footing ................................................... 11
C. Plumbing Hookup .............................................................. 12
D. Electrical Lines ...................................................................... 12
E. Installation of Pex Pipe ....................................................... 12
F. Filling Boiler with Water ..................................................... 12
G. Plumbing Parts Needed ................................................... 13
H. Adding Bypass Valves ..................................................... 13
I. Installing Heat Exchanger In Plenum ........................... 13
J. Installing Heat Exchanger In Small Plenum ............. 15
K. Bleeding the Heat Exchanger .......................................... 15
L Air Flow through Plenum .................................................. 16
M. Thermostat Wire Layout .................................................... 16
IV. Other Hook Ups - Heating Domestic Water, Pools and Spa’s
A. Layout of Water Lines for a Sidearm or Plate Heat Exchanger ........................................................................................................ 17
B. Warm Weather Operation and Hot Water Bypass ................................................................................................................................ 19
C. Heating a Pool or Spa ......................................................................................................................................................................................... 19
D. Hooking Up The Outdoor Boiler To An Existing Boiler ...................................................................................................................... 20
V. Maintenance
A. Cleaning Out Ash ................................................................................................................................................................................................ 21
B. Creosote ................................................................................................................................................................................................................... 21
C. Door Seals ................................................................................................................................................................................................................ 21
D. Pump .......................................................................................................................................................................................................................... 21
E. End of Season ........................................................................................................................................................................................................ 22
VI. Trouble Shooting
VII. Disclaimer
B. Going Away ............................................................................................................................................................................................................ 24
Mail in Warranty Card ......................................................................................................................................... 25
Type of fuel: Wood and coal only.
Location: Outdoor use only.
Electrical Rating: 115 VAC, 5A max, 60 HZ
Min. Circuit Breaker: 15 Amps.
Draft Blower: 146 CFM max, 115 VAC
Water Pump: 115 VAC, 2A max.
C. Clearance to Combustibles Required
Front: 10 feet
Flooring: Non-Combustible
Chimney: 18 inches
Top, Rear and Sides: 18 inches
D. Boiler Dimensions
NCB-120 126,000 BTU, 120-gallon water tank, 2,000 sq ft.*
NCB-175 184,000 BTU, 175-gallon water tank, 4,000 sq ft.*
NCB-250 263,000 BTU, 250-gallon water tank, 6,000 sq ft.*
NCB-325 342,000 BTU, 325-gallon water tank, 8,000 sq ft.*
Firebox Sizes
*
Will heat up to (x)sq ft (This must include all heated areas of home as well
as basement.) with proper installation, properly insulated building and
when properly seasoned hardwood is used (20% moisture content).
Deduct a minimum of 500 sq ft if heating domestic hot water.
Model Description Width Depth Ash Pan
NCB-120 oval 25.5” W x 31” H 36” 39” X 11.75”X 4”
NCB-175 29” cylinder 28” 36” 39” X 11.75”X 4”
NCB-250 29” cylinder 28” 54” 39” X 11.75”X 4”
NCB-325 29” cylinder 28” 72” 39” X 11.75”X 4”
Do not operate this equipment for anything other than its intended purpose or for anything other than in
accordance with the instructions contained in this manual and all other instructions accompanying the boiler. It is
important to observe safety precautions to protect yourself from possible injury. Among the many considerations, you
are advised to observe all safety stickers on the boiler.
A qualified electrician must wire this boiler in accordance with the National Electrical Code.
1. Never use any type of petroleum based product, charcoal starter, lighter fluid, lantern fuel, kerosene or any
other flammable accelerant to start the fire in the firebox of your boiler. Keep all such liquids well away from firebox.
2. If using antifreeze, use only non-toxic, follow manufacturer’s recommendations on mixing ratio and test
annually. Keep containers of antifreeze, which is flammable, well away from the boiler.
3. The use of treated wood (painted, treated, etc.) and any other salvaged material that can emit toxic gases into
the environment and is corrosive towards the components of the appliance is not allowed and voids your
warranty.
4. The boiler is designed to burn seasoned cordwood and coal only. Do not burn garbage, household or yard
waste. This is illegal in most areas. Burning these materials can reduce the life of the boiler and will void your
warranty.
5. When opening the fire box door, pause momentarily between the first latch and the safety latch to allow any
combustion gases to burn off. Always close the firebox door securely.
6. Check to be sure the ash pan is fully inserted. Leaving a small crack or opening can cause over-heating in the
firebox, boiling the water off and voiding your warranty.
7. Always use proper care when installing, operating and maintaining the boiler.
8. Always wear protective gloves and glasses and be aware that hanging and loose clothing can catch fire.
9. Do not modify the boiler.
10. Failure to heed these warning or any additional warnings on the boiler may result in an accident causing
personal injury and damage.
CALL YOUR LOCAL MISS DIG HOTLINE BEFORE YOU DIG TRENCHES!
Disposal of Ashes:
Caution! Ash pan is hot! Turn blower off before removing! Use heavy gloves to pull out ash pan drawer to remove
ashes. The ashes should be placed in a metal container with a tight fitting lid. The closed container should be placed on
the ground or a non-combustible floor. Once cool, the ashes may be disposed of.
All installation and operation must follow Federal, Provincial, State and Local Codes
Page 5 of 25
F. 20 Year Limited Warranty
Nature's Comfort LLC, of Shipshewana, IN 46565 warrants material and labor on any defects in workmanship on the fire drum for a period of 20
years from the purchase date to the original owner only (see proration below). If there is a leak in your properly delivered, installed and maintained
Nature's Comfort boiler, we will repair for the first 5 years at no cost and prorated after that (see below). The water jacket is warranted for a period
of 10 years from the purchase date to the original owner only (see proration below). Repair can be denied if the unit's water jacket has exceeded
220 degrees.
This warranty is limited to defective parts and excludes any incidental and consequential damages connected therewith. Nature's Comfort does not
warranty damage or malfunction to any interior portion of the boiler caused by ash corrosion or allowing the unit to overheat. Ash must be kept
cleaned out and all interior portions must be completely cleaned out of all ashes and creosote a minimum of 2 times per year, half way through the
heating season and at the end of heating season. The chimney must be covered when the boiler is not in use. Caulk around chimney and float
stack must be inspected monthly and re-sealed if necessary. Caulk sealant and rope gaskets are not covered under this warranty. Damage caused
by abuse, neglect, accidents, improper installation, customer or dealer modification, overheating and/or freezing will not be covered under warranty.
Damage caused by burning flammable materials (i.e. petroleum products) will not be covered under warranty. Nature's Comfort does not warranty
boilers against environmental conditions out of its control. Nature's Comfort does not warranty or guarantee against your area's governing laws or
changes in your area's governing laws that will affect the use or nonuse of the unit.
Nature's Comfort is not responsible for replacement of water, water treatment, antifreeze and glycol, costs of transportation or shipping charges. On
sight non-warranty parts and labor will be provided at the discretion of your dealer. Please contact your dealer for their current non-warranty rates.
Labor for repairing or replacing parts under warranty will be covered by your dealer.
Nature's Comfort's wood boilers are not meant to be your sole source of heat. It is the responsibility of the owner to have a backup system in place.
If you do not have a backup source of heat you are at risk of damage due to lack of heat. Nature's Comfort will not warranty or be responsible for
any damage caused by lack of heat at your premises or for any cost incurred from using a backup heat system in the event of a boiler failure.
There is no written or implied performance warranty on the boiler as Nature's Comfort has no control over the installation, structure insulation,
maintenance, daily operation and heating demand on a unit or what is burned in the boiler. Nature's Comfort will not cover or be held responsible
for any cost of wood or coal burned in excess of what is expected or considered normal as installation, fuel being used, structure size and insulation
conditions are out of its control.
Your boiler must have "Nature's Comfort Boiler Treatment" added during initial filling with water, antifreeze or glycol and must be tested when first
filled and then annually at the end of a heating season to ensure proper concentration (1,000-1,5000ppm, never below 500ppm minimum or above
2500ppm max of nitrites) for your warranty to remain valid. The water jacket must remain full of properly treated water at all times after installation
save for draining, flushing and re-treating. Minimum recommended initial mix ratios for each boiler is: NCB120 & NCB175 - 1.5Qts; NCB250,
GT220 & GT6000 - 2Qts; NCB325(G) & GT500 - 3Qts, NCB-575 - 6Qts. Contact Nature's Comfort or your dealer to obtain water treatment. You
must have your water tested for nitrites by your dealer or you may order a more comprehensive test from Wood Boiler Solutions LLC to also satisfy
warranty requirements. You may order over the phone at (920)324-2007 or you may order online at www.woodboilersolutions.com using promotion
code "NCLLC" to receive a 15% discount. Always request results to be sent to you and you must keep them on file to show proof of treatment and
testing if warranty work is ever needed. Testing done by anyone other than a dealer, Wood Boiler Solutions, a certified lab or Nature's Comfort will
not be accepted for warranty claims but is encouraged for monitoring treatment levels to obtain the maximum life out of a Nature's Comfort boiler,
particularly if water is being added throughout a heating season. Nitrite test kits are available from your dealer or Nature's Comfort. Drain, flush, refill and re-treat if water is ever not clear. Visit www.naturescomfortllc.com/warranty each year for current treatment and testing requirements.
Nature's Comfort On-Site Warranty Proration:
Nature's Comfort will pay costs of warranty work based on the following proration:
Fire Drum: Years 1 - 5: 100%, Year 6 - 90%, Year 7 - 80%, Year 8 - 70%, Year 9 - 60%, Year 10 - 50%, Year 11 - 40%,
Year's 12 - 14: 30%, Years 15-20: 20%
Water Jacket: Years 1 - 5: 100% Year 6 - 80%, Year 7- 60%, Year 8 - 40%, Year 9 - 20%, Year 10 - 10%
1 Year Warranty on Other Components
Nature's Comfort warranties, to the original owner only, any component a part of the boiler that is defective during normal usage for a period of 1
year from customer's date of purchase. Shipping for returning defective parts is not included. Replacement/repaired parts are obtained from the
dealer purchase was made through. After one year, your dealer may charge you for any parts provided or work performed. No warranty parts will
be provided without first returning the defective part. Replacement/repaired parts carry a 90 day warranty or the fulfillment of the 1 year warranty
period, whichever comes later. Pump failure due to water quality issues or not bleeding the air out from the bearing before startup are not covered
under warranty.
All claims under this warranty must be made through the dealer where the boiler was purchased. If an inspection by the dealer indicates that a
warranty claim is justified and that all conditions of this warranty have been met, Nature's Comfort will repair or replace the problem part according
to the above proration. Proof of purchase, treatment and testing and return of the defective part (if applicable) must be provided by the owner of the
boiler before any warranty is given. All costs of removal, shipment to and from the dealer or Nature's Comfort and losses during shipment and
reinstallation and any other losses due to the stove being removed shall be covered by the owner of the boiler. If your dealer no longer exists,
please contact Nature's Comfort via email: warranty@naturescomfortllc.com. It may be necessary for you to obtain quotes from one or more local
professionals.
This warranty is subject to change without notification. Please visit www.naturescomfortllc.com for the most up to date warranty and installation
information.
Nature’s Comfort LLC, 3790 N SR 5, Shipshewana, IN 46565
Treatment & Testing
Warranty Procedure
Page 6 of 25
G. Customer Warranty Card
Please fill in the following information and keep for future reference.
A duplicate page for mailing to Nature’s Comfort is at the end of this manual. Retain this copy for your
records.
Please keep this manual with all other important papers. The information in this manual is necessary for the
installation, operation and proper use of your boiler. If you should ever have a problem or question please refer to this
manual or call your dealer. Please have your serial number ready. This is found on a silver tag on the back of the rear
access door or stamped into the fire door jamb on the top left. If your dealer does not have the information you need,
request they contact Nature’s Comfort and your dealer will be further educated to provide the best possible customer
service. Please keep in mind that Nature’s Comfort built your boiler but did not install it and has no control over the
installation, the efficiency of the building’s insulation or what is burned in the boiler. www.naturescomfortllc.com
Water Treatment
The boiler water must be treated with and tested for Nature’s Comfort boiler treatment at installation and annually
thereafter for the required concentration of nitrite (1,000-1,500ppm, 500ppm min) so there will be no rust or corrosion.
This is required to keep your warranty valid. Please see warranty page for complete details and instructions on
treating and having your water tested.
Check here for each year tested for your records:
Year 1__2__3__4__5__6__7__8__9__10__11__12__13__14__15__16__17__18__19__20__
21__22__23__24__25__26__27__28__29__30__31__32__33__34__35__36__37__38__
(Area Code) (Number)
(name)
(Phone number)
Page 7 of 25
II. Best Outdoor Boiler Burn Practices
Read and follow all operating instructions.
A. Fuel Used: You may burn any hardwood, softwood, pallets that have been split up and coal but NEVER burn
driftwood, painted, stained or pressure treated wood. Do not burn trash, plastics, gasoline, rubber, naphtha,
house hold garbage, material treated with petroleum products (particle board, railroad ties and pressure treated
wood), leaves, paper products and cardboard. If you burn softwood, the boiler will need cleaning more often.
B.Loading Fuel: For a more efficient burn, always add wood before the previous load has burned out. Most often
the boiler can be loaded in the morning and at night. Burn times vary from 6-24 hours depending on fuel being
used, installation and size of area being heated. Nature’s Comfort makes no guarantees on burn times. When
burning coal, load coal before wood.
C.Starting fire: Do not use lighter fluids, naphtha, gasoline, or chemicals. Use small pieces of split kindling together
with crumbled newspaper and add larger pieces. Remember: The smaller the better, the dryer the better.
D.Location: It is recommended that the boiler be located with due consideration to the
prevailing wind direction. Chimney height can be easily extended with 6” stovepipe.
1We recommend a distance of at least 100 feet be kept if prevailing winds blow towards any other residence
not served by the boiler, it is recommended that the stack be at least 2 feet higher than the peak roof line of
that residence.
2If located more than 100 feet but no more than 150 feet to any residence, it is recommended that the stack be
at least 50% of the peak roof line of that residence, plus an additional 2 feet.
3If located more than 150 feet but no more than 200 feet to any residence, it is recommended that the stack be
at least 25% of the height of the peak roof line of that residence, plus an additional 2 feet.
Chimney height relative to nearest downwind neighbor
Always comply with all applicable state and local codes and laws.
E. Wood Recommendations
For maximum efficiency and burn times, you should only burn wood that has been seasoned for 12-24 months and
sheltered from rain and snow. Burning unseasoned wood is wasteful, inefficient and can shorten the life of your boiler
from corrosion due to excess creosote. Freshly cut, “green” wood uses much of the combustion energy to dry out the
excess moisture. Ideally the wood should be split 6-8” in diameter and cut 12-16” to aid in seasoning and should be
around 20% moisture content by weight. Whole rounds burn well and are cheaper, but this type of wood also will have
to be dried much longer, especially if in larger diameters.
Page 8 of 25
The following are general guidelines for wood selection:
Keep wood covered but open to the wind as rain and snow will greatly hamper the seasoning.
Hardwoods burn longer than softwoods as they are denser and have more available BTU’s.
Larger pieces burn longer than small pieces but take longer to season properly.
20% moisture content is optimum.
Wood with higher moisture content wastes energy to dry out wood.
Too low of moisture content (very dry, old wood) burns rapidly and inefficiently.
F. Burning Coal
As a general rule, coal is more difficult than wood to burn. If you are primarily burning coal, adapter grates can be
purchased from Nature’s Comfort that will sit in place of the center firebrick(s). For best results coal should be piled 610” deep and mixed with wood to help the air pass through. To shake and settle a bed of coals, use a hoe or a rod
with a hook on the end to place in a slot on the grate to then rock back and forth.
G. Heating the Home
The NCB boiler is designed to save energy and provide the most comfortable heating available. It heats your home
by heating a firebox surrounded by a steel tank filled with water. The boiler is a non-pressurized boiler with an
atmospheric vent. The hot water is then circulated through underground pex pipes to a water coil (heat exchanger)
installed inside your existing central duct system. (Typical of most systems)
A typical water-to-air heat exchanger much like a small radiator or
heater core in a car is installed in your ductwork. When air blows
through it, heat is extracted and hot air blows out of your vents.
The Nature’s Comfort outdoor boiler can also be connected to any existing hydronic radiant heating system that
operates at 180 degrees or less using a plate heat exchanger.
H. Heating Domestic Hot Water
To heat your domestic water, heated water from the outdoor boiler is circulated through a “water to water” heat
exchanger which must be installed on your existing water heater. This is either a plate or side-arm style heat
exchanger. The hot water from the boiler usually goes to the exchanger on your furnace and then to the exchanger at
your water heater. You may use either style exchanger with your water heater. See page 19 for a layout of piping for
a sidearm.
I. Thermostat Controls
The only visible addition to the heating system inside your home is a second thermostat, which should be located near
the existing thermostat. This second thermostat must be installed to operate your existing blower for forced air or
your circulation pump for radiant heat and needs to be set higher that your original thermostat by 10 degrees so your
existing furnace will automatically take over to maintain your household temperature if your boiler is not running.
Please see page 18 & 19 for an example wiring layout.
Page 9 of 25
The outside boiler has a hot water thermostat (aquastat) with a thermocouple that is inserted into a brass drywell that
Single
-
Zone setup
senses the water temperature of the unit. When the temperature of water in the boiler falls below the “low”
temperature setting on the aquastat, the blower turns on to build a hotter fire and remains on until the water
temperature in the boiler reaches the “high” temperature setting of the aquastat. Temperature may be set anywhere
between 160 – 180 degrees. When heating your home through a radiant system, the recommended setting is 180.
When heating with a forced air system, the recommended setting is 170. The aquastat also has a temperature swing
setting that is adjustable from 5 – 30 degrees. Recommended setting is 15 degrees which provides for longer run
times to burn off creosote buildup.
J. Pex Pipe Connections
Boiler shown is set up as a single-zone. All boilers save
for the NCB-120 come with ports for 2 hookups (2nd
Pump not included.)
1. Red Pex pipe goes from the pump to
heat exchanger(s) in home. Please
note! The pump that came with your
boiler may not be the correct size for
your installation. Please consult your
dealer for sizing as water flow is
essential to the proper & efficient
operation of your installation.
2. Blue Pex pipe returns from home to
lower port opposite of pump. Please
note! This is critical for proper circulation
inside the water jacket. If installed on
the lower left, hot spots will occur on the
right side of the water jacket causing
boiling and loss of water due to steam.
3. Power to pump, aquastat, solenoid and
blower.
4. Blower to feed oxygen to fire.
5. Pump to circulate water. (One is included.)
6. Aqua-stat sensor for turning on blower and solenoid.
7. Solenoid with adjustable damper. (After
adjusting damper, make sure to tighten
jam nut.)
Note:
Water flows out at top and in at bottom. (See
arrows #1 and #2.)
Temperature gauge shown was optional on
older models.
Page 10 of 25
K. Insulated Pex Pipe
We highly recommend the use of insulated pex pipe for the best heat transfer possible from the boiler to your home.
4” triple wrap or 5” five wrap insulated pipe is available for purchase through your dealer or Nature’s Comfort.
L. Adjusting Airflow On Draft Blower
The turn buckle must be adjusted so the damper covering the intake to the blower is open only ¼” at the widest point
for wood and slightly more for coal.
III. Installing The Boiler
If installing yourself, consult with your dealer for suggestions before getting started.
A. Location of Boiler
The outdoor boiler should be located a minimum 10 feet away from a structure, with the door facing away so all fire
danger is removed from your home. The boiler may be installed as much as 250 feet away using an appropriately
sized pump and piping and still heat your house and hot water. However, if the boiler is located more than 100 feet
away, you may experience inefficiency and heat loss. A larger pump than the one supplied may be needed for
distances over 100 feet and/or any rise in elevation over 15 feet.
Locate the outdoor wood boiler where it will be convenient for refueling and wood storage. Pex pipe and power lines
are to be installed underground between the house and the boiler and must be buried below frost lines.
1 It is recommended that the boiler be located with due consideration to any neighboring residences and to the
prevailing wind direction.
2. Do not locate the boiler within 100 ft of a residence not served by the boiler. Be considerate of neighboring
residences, properties, parks, etc.
3 Review the recommended smoke stack heights on page 8.
4 Do not locate the boiler near any combustible materials, gasoline or other flammable liquids or gases.
5. The boiler should be located away from dry grassy areas and any buildings to minimize
danger of fires.
6. Check with your insurance company and local codes or ordinances.
7. Do not install the boiler in an area where nearby structures or trees might cause down drafts.
8. Typically, outdoor wood burning boilers are located 40 to 100 ft down wind from the structure served.
9. Locate the boiler to allow easy access to wood supply.
10. To aid in smoke dispersal, extra chimney lengths may be required depending on the distance to surrounding
structures. See page 8 for additional guidance.
11. The boiler requires a 15 amp 110vac electrical service to operate.
Failure to keep the boiler area clear and free of combustible materials, gasoline and other flammable liquids
and vapors can result in severe personal injury, death or substantial property damage.
B. Concrete Block Footing
A full concrete pad or footings just under the feet are not necessary for the installation for your boiler, but are
recommended to prevent frost heaving. Four concrete footing blocks 8” X 16” X 4” will suffice if desired. You may add
additional layers of blocks for ease of loading wood. The next figure is for block placement, not foot dimensions.
It is recommended to insulate the underside of the boiler with minimum 1” non-combustible hardboard insulation and you
may also install non-combustible type of skirting around the feet and control area to prevent wind from reducing efficiency.
Page 11 of 25
C. Plumbing Hook Up
1. Plumbing and electrical connections are made through the rear access door.
2. The water lines must be buried below the frost line to prevent freezing. The depth of the trench varies in
different regions of the country. Be completely sure about the correct depth needed before the insulated pex
pipe is installed underground. Contact your local building inspector’s office for this information.
4. If you purchased insulated pipe, it may contain twine for pulling electrical wire. Do this before the pipe is in the
trench for ease of pulling.
5. If more than one building is to be heated, additional pipe must be installed.
6. If you have rocky ground, make sure you place straw around the pipe before back filling, giving extra
protection against punctures.
7. Keep 90’s to a minimum as each one adds 1 foot of head pressure, reducing the rate of water flow. Use
sweeping bends and for tight radiuses, use ¾” rubber heater hose.
HINT: If only one color of pipe is used, identify and label the water lines before back filling.
D. Electrical Lines
A qualified electrician must wire this boiler in accordance with the National Electrical Code.
Your Nature’s Comfort boiler requires installation of 1-15amp 110vac circuit to operate the equipment in the
boiler. The size and type of electric wire to be installed depends on the distance from the boiler to the house. If
the boiler is less then 100 feet from the house, #14 AWG UF cable is the smallest wire that may be used. If the
distance is greater than 100 feet, #12 AWG UF cable must be used. A maximum of 5 amps is used by the boiler if
all standard equipment is running or on and dual 100watt light bulbs are used.
E. Installation of Pex Pipe
Keep the pex pipe underground as it enters the house. Make sure to seal around the pipe to prevent water from
entering structure. This can be done with a can of expanding foam. If conditions require the pipe to be above
ground for entering the home, make sure to insulate thoroughly.
F. Filling Boiler with Water
Once all piping connections are complete, fill with 20 gallons of water and drain. Do this until water comes out
clean. Do not start circulation pump until it has been primed!Loosen the top screw on the pump until a
steady stream of water flows and all air has been purged. Being a wet-rotor unit, if the pump runs dry at all, it will
seize up as the bearings rely on lubrication from the water.
Pour the Nature’s Comfort boiler treatment through the float stack then fill with water using a hose or if you have
installed a fill line, open the valve and allow it to fill until the float starts to rise. Use water that is softened or has
Page 12 of 25
low iron content if possible. During the first heating cycle the water might expand and overflow. This is normal and
will occur anytime too much water has been added.
After priming and starting the circulation pump and bleeding the heat exchanger let your boiler heat up and run for
24 hours then top off the water again. The ideal water level is at the beginning of a heating cycle for the level
indicator to be at the top of the rubber cap or higher. The water level will rise and fall during operation as water
expands and contracts with temperature changes. Be sure to keep your boiler within 3” of being full at all times
including through the summer as this will keep your boiler free from corrosion and when in use, from overheating
causing circulation pump failure.
G. Plumbing Parts Needed
1. A 1” pex crimp x 1” NPT is needed to install the outgoing pex line into the flange that is supplied and already
mounted to the lower end of the circulation pump. The flange is a female 1" NPT. The return line must be
installed in the opposite lower corner for cross flow of the water jacket so no hot spots are created on the
firebox. Use a valve for isolating.
2. Extra pex fittings can be purchased from your local hardware or plumber.
The pex pipe connected to the bottom of the pump runs to the house and normally runs to the heat exchanger
installed in your furnace or a plate heat exchanger for a hydronic radiant system. See page 21 for more
information on hooking up a brazed-plate heat exchanger.
3. A circulation pump comes already mounted to the boiler with a shut-off valve. Install an additional valve on the
return port so if the pump ever has to be changed, the water supply can be shut off so for easy replacement. It is
highly recommended that you purchase a 2nd pump as a spare for if your pump should ever fail as your
boiler cannot function without it. This will prevent downtime, loss of heat to your home and over-heating of
your boiler. Please note! The pump that came with your boiler may not be the correct size for your installation.
Please consult your dealer for sizing as water flow is essential to the proper & efficient operation of your
installation.
Add a valve to the return line at the boiler so if repair or service is needed on lines or equipment, the water in the
boiler can be isolated without having to be drained.
Note: For larger homes, 1-¼ pipe may be needed for maximum BTU output. A 1-¼” pipe can carry up to 37%
more BTUs due to higher water flow. The fittings above would need to be changed to accommodate 1-¼” Pex.
The Armstrong E9 pump available from Nature’s Comfort has the ability to do this in a 1” pipe within distance &
height limitations.
H. Adding Bypass Valves
Adding a bypass valve system at each heat exchanger is a good idea so that if there is a potential problem such
as a stopped up heat exchanger, it can be diagnosed & serviced easily by the owner as well as being used for a
summer bypass as explained on page 20 (Figure shows 3-valve setup used for bypass and isolation).
I. Installing the Heat Exchanger in the Plenum
Note: It is recommended that you contact your local plumbing/heating contractor to supply and install the
heat exchanger unless you have the tools and experience required.
The heat exchanger must be installed below the evaporator coil if you have air conditioning. This is required
since the heat exchanger may freeze and crack when the air conditioner is used. If it is not possible to place the
heat exchanger between the furnace and the evaporator coil, you must drain the heat exchanger before using the
air conditioner. It is recommended that a bypass system of valves be installed for servicing and draining the heat
exchanger if necessary. (Noted above)
The heat exchanger must be installed so that it is airtight. No air must be able to flow around it or out of the
ductwork. Use adhesive backed foam tape (used for insulating doors and windows) around the water coil. Use
foil tape to seal off the heat exchanger and the hole you make.
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Make sure the fittings for the supply and return lines are easy to get to once the heat exchanger is installed.
You should be able to find a heat exchanger to fit most popular sizes of plenums. If you are unable to your
ductwork must be modified to accept the heat exchanger. This is best left to a professional unless your ductwork
is made up of fiberboard. In all cases wear proper protective gear (gloves, safety glasses, etc)
Measure the width of the heat exchanger (Dimension A in next diagram). Measure the thickness of the heat
exchanger (Dimension C).
Start by cutting a hole in the side of your ductwork the thickness of the heat exchanger (Dimension C) and the full
length of the ductwork (usually Dimension A).
WARNING! Metal edges are very sharp! Wear protective gloves and use caution!
Slide the heat exchanger into the hole for a test fit. Ideally the tubes (D and E) should stick out of the plenum [see
diagram on previous page]. The header and tubes (F) can stick out of the plenum as well, if necessary.
As long as the entire coil surface (B) is in the plenum, operation should be fine even if the header (F and G) sticks out.
While test fitting try to determine how much tape is needed around it. A different width may be needed on different
sides. You can purchase different widths of tape so that it will fit and seal properly.
Place foam tape around the outside of the heat exchanger to seal off so that it fits tight and air can’t blow by it.
The heat exchanger needs to be installed so it won’t move around. The easiest way is to fabricate some pieces of
metal into andL’ shape, approx. the length of the heat exchanger like shown above.
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Install the braces the proper width apart as shown above. Secure them in place using pop rivets or self taping screws.
You will need four pieces, two on the top and bottom.
Slide the heat exchanger carefully into the plenum to check the fit again. Once proper fitting is verified, you can seal
off the ends of the heat exchanger and the hole you made in the plenum with foil tape made for ductwork.
J.Installing a Heat Exchanger in a Small Plenum
You can install a heat exchanger in a plenum that is smaller than the length of the heat exchanger, as follows. Make
cuts at the top and bottom of the plenum, usually 4 inches long (the width of the heat exchanger) as shown below.
You may need to do this on both sides of your ductwork depending on your heat exchanger size.
Cut another line vertically, between the other two cuts, right in the middle as shown.
Slide the heat exchanger through the front hole to the back hole so it protrudes out the front and back of the plenum.
Ideally the core of the heat exchanger will be entirely within the plenum.
Crimp the sheet metal to the edge of the heat exchanger. This not only forms a virtually airtight seal, but it also
supports the heat exchanger as well.
K. Bleeding the Heat Exchanger
With the pump running (Prime first and turn the thermostat up so that the pump comes on), simply close the brass
valve on the return side, holding for 2-3 seconds, then open quickly. Repeat the procedure four times or until you
cannot hear air rushing through the line.
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L. Air Flow through Plenum
The motors on most force air furnaces have three speeds to provide various rates of air movement. Please
consult a local furnace specialist if you want to change the airflow of your existing furnace system.
M. Thermostat Wiring Layout
The two diagrams below are options for controlling the furnace blower independently of the existing heat source. Set
the existing T-stat 10 degrees below the new T-stat.
Follow this diagram if you have a 4 wire thermostat system for the existing furnace controls.
Mount the new T-stat next to the existing one and run the jumper wires behind the drywall.
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Follow this diagram for when you do not have a 4 wire thermostat system. Mount the new T-stat in a central location
on the main floor of your home where you can easily run a wire to the furnace.
Put the transformer & relay in the furnace control area.
IV. Other Hook Ups - Heating Domestic Water, Pools and Spa’s
A. Layout of Water Lines for Sidearm or Plate Heat Exchanger
See diagrams on the next page. For a sidearm HX, the hot line from boiler must enter the top side port. This
creates twice the domestic water flow through the sidearm as opposed to coming in at the bottom. For the
fastest recovery, install a small circulation pump on the domestic side that is controlled by a thermodisc switch.
Hookups to the domestic side must be connected to drain and pressure relief ports. Make sure to keep the drain
valve & pressure relief valve in service & purge all air from the piping and HX. The plate HX drawing shown is
for a pre-heater setup. Leave utility energy on for this to maintain the water temperature. As water is used it will
then be heated by the plate HX. You may also use a plate HX to bypass the water heater for on-demand
operation. Always use a mixing valve to prevent scalding water temperatures.
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B. Warm Weather Operation and Hot Water Bypass
Operation in warmer weather will be tricky as too many coals will cause the water jacket to boil if not enough heat is
being used. To compensate, load less wood and/or purchase a chimney damper to reduce draft through the chimney.
Adequate water circulation is critical for preventing water from boiling (see page 11). Make sure all gaskets and air
intakes are properly sealed to prevent any extra air from feeding a fire.
For heating of domestic hot water without heating your home, install a 3-valve bypass system shown below. This
permits you to use your boiler during the spring, summer and fall seasons to heat your hot water when you may not
need or want to heat your house. The bypass permits the water to run from your boiler to the hot water heater and
bypass the heat exchanger in the furnace plenum. Use of union fittings between the isolation valves and heat
exchanger for easy removal is recommended as the plenum heat exchanger must be drained or removed so the
water doesn’t freeze when running air conditioning.
C. Heating a Pool or Spa
Please contact your local pool/spa contractor if this boiler is to be used to heat a pool or spa. You must consult with a
pool/spa specialist since the chemicals used in a pool/spa are destructive to your boiler. A stainless steel (or 90/10
copper/nickel alloy) tube & shell water-to-water heat exchanger must be used to transfer heat from the boiler to a pool
or spa. Pool heat exchangers are available from Nature’s Comfort. For sizing you will need to know the volume of the
pool in cubic feet or gallons. Be sure to install isolation and bypass valves for easy servicing and also place before a
chlorinator.
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D. Connecting the Boiler to an Existing Indoor Boiler
A plate heat exchanger is needed to transfer heat from the outdoor boiler to another indoor boiler or hydronic system
so that the two systems remain isolated from each other.
As shown in the above figure, the two systems are totally isolated from each other so that the existing hydronic
system remains undisturbed and functions exactly as before. All pumps and controls remain essentially the same on
the existing system. A second T-stat is needed to run the zone pumps independently of the indoor boiler burner. If a
30-plate unit or larger is used, a larger circulation pump on your boiler may be necessary for proper water flow.
Water that circulates through the boiler is never circulated through the home’s hydronic system or vice-versa.
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V. Maintenance
A. Cleaning Out Ash
Moisture combined with ash will eat through a boiler in short order and ash corrosion is NOT covered
under warranty.
With our grate and ash pan, ashes can be removed while the fire is still burning. Use a hoe or other tool to pull
ashes away from the chimney. Make sure to turn off power to the blower before removing ash pan or opening
firebox door and wear heavy gloves and safety glasses.
B. Creosote - Formation and Need for Removal
1. When wood is burned slowly (smoldering) it produces tar and other organic vapors which combine with
expelled moisture to form creosote. This occurs on a larger scale when there is too much moisture content in the
wood being used, is corrosive and can shorten the life of your boiler. The creosote vapors condense in the cooler
chimney flue of a slow-burning fire. As a result, creosote residue accumulates on the flue lining. When ignited, this
creosote makes an extremely hot fire. Dry, seasoned wood is the best practice.
2. The chimney must be inspected at least twice a year during the heating season to determine if a creosote
buildup has occurred. If creosote has accumulated it must be removed to reduce the risk of a chimney fire.
3. All creosote and ash must be cleaned from the firebox twice a year, preferably halfway through the heating
season and immediately after the heating season using a scraper and wire brush.
C. Door Seals
Check rope seals on the loading door and ash pan periodically during the heating season as they will compress.
Loosen the bolts on the hinge and/or latch to re-position the main door for tightening the seal if necessary. If the
latch has no remaining adjustment, add washers behind the door handle to further tighten the latch side. If there is
no more adjustment available and the door is not sealing properly, the rope seal must be removed, cleaned &
loosened up, reversed and re-installed or replaced with new rope. For installation, re-position the door hinge and
latch as far out as possible and install the rope seal with a liberal amount of high temperature caulk behind it for
maximum adjustment. Make sure to push the rope to the outside of the corners to mate properly with the jamb (do
not stretch the rope). Bounce the door closed a couple times to custom fit the seal to the jamb, then leave door
open until the caulk behind the rope is fully cured (ensure there are no raised portions that will leave gaps!). Readjust door to properly seal. Contact your dealer or Nature’s Comfort for new rope or caulk if needed. This is a
normal maintenance item and not a warranty issue.
D. Pump
It is highly recommended that a customer purchase an additional pump to have as a spare.
Inspection: Before installing, inspect the pump shaft by removing the large silver screw to expose the top of the
shaft and turn back and forth with a screw driver to make sure the shaft was not broken during shipping. Broken
shafts are not covered under warranty unless found and noted before installation and startup.
Startup: Make sure the lines are filled and prime the pump by cracking the upper pump flange to bleed the air out of the impeller and volute. IMPORTANT: The large, silver bleeder screw must also be removed from the
pump before running for the first time to bleed all air from the bearings or the pump warranty will be void.
After priming the pump, remove and leave the bleeder screw out, start the pump to finish bleeding all air out of the
bearings, shut off the pump and re-install bleeder screw. You may now run your pump.
Inspection & Maintenance: Loosen the bleeder screw once a week (less often as experience shows otherwise)
to flush the bearings to maximize pump life, especially for those with poor water quality. It is highly recommended
that a customer have their own test kit to monitor treatment levels once a month and add if needed. If when
getting a sample for a test the water is not clear the boiler needs to be shutdown, drained, flushed, re-filled &
treated. Customers must still have a test done by their dealer or Wood Boiler Solutions per the warranty with full
details on our website: http://www.naturescomfortllc.com/boiler-warranty/
To inspect the upper bearing and shaft, unplug the pump, close the valves on either side of the pump to isolate
(one should always be field installed right before the return line enters the water jacket to be able to fully isolate
the pump, lines and HX’s) and remove the bleeder screw to look at the upper bearing to make sure it’s not worn
out causing the rotor to scrub on one side of the canister housing.
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To inspect and clean the rotor and canister, take the 4 Allen screws off to remove the motor from the volute.
***NOTE: The rotor shaft is ceramic. If it or the pump is dropped, hit, bounced or jarred it can fracture
and/or break. Use care when handling.*** Gently use a screwdriver to pop the lower SS plate (also serves as
the lower bearing) from the canister to pull the rotor out of the canister. Use a wire brush to clean off any scale
buildup from the rotor and canister. White vinegar or a calcium and lime cleaner can assist for stubborn buildup.
Do not allow any liquids to enter the motor.
Squealing: Comes from the bearings not having the air bled before running or not having enough clearance from
scale buildup around the bearings or around the rotor inside the canister causing oscillation (vibration). Scale
buildup happens if the water has too much hardness and is something that is greatly accelerated if the water does
not have the proper amount of treatment. Vibration can lead to fracturing and breaking of the shaft and is
not covered under warranty.
Scrubbing or ticking noise: Results from scale build up or the bearings and/or shaft wearing out allowing the
rotor to come in contact with one side of the canister. All eventually lead to “seizing” up. Not bleeding air from the
bearings, improperly treated water and/or high mineral content (hardness is the biggest problem) and TDS (total
dissolved solids) that are abrasive all result in premature wear of the bearings or scale buildup.
Water: Since water quality characteristics greatly vary across the USA, some customers get much longer life out
of a pump than others. Filling a boiler with softened water, adding and maintaining treatment so there’s 1,0001,500ppm of nitrites is the best thing you can do for pump and boiler life. While there is a one year warranty on
our pumps (from customer’s date of purchase), they must first be inspected and an attempt made to clean and put
back in service before a dealer determines one to be “failed”. Proper treatment and records must also be present
for the warranty to be honored. If a customer had a water test pass but adds water frequently due to boiling or
over-filling from improper operation this will bring down treatment levels quickly, possibly below the minimum level
of 500ppm and void a warranty.
E. End of Season
1. Power: Turn off power supply at the appropriate circuit breaker
2. Chimney: Inspect & Clean. Cap the chimney to keep rain water out. Re-seal caulk.
3. Firebox & Remove ashes, soot, and hardened deposits from the fire chamber
Ash Tray: by using a putty knife and/or wire brush. Coat the inside of firebox with a light coat of
motor oil or WD-40 to protect the steel during the off-season.
4. Doors: Oil door hinges and latch.
5. Plumbing: Ensure fittings on both ends of tubing are tight at all locations.
6. Water TreatmentUnless you are using anti-freeze or glycol, make sure your water is tested and has
enough Nature’s Comfort water treatment so there will be no rust or corrosion. Replace
water & treatment yearly. See warranty for further details.
Moisture from rain or condensation must not be allowed to accumulate in the firebox or ash pan during nonuse. Failure to perform preventive maintenance may result in severe corrosion and major damage to the
boiler. This is NOT covered under warranty.
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VI. Trouble Shooting
Problem Cause Solution
Boiler dose not come up to temperature. Green or soft wood is being used,
Boiler is in the open were the wind
blows under boiler
Use dry, hard wood
Take one or two inches of hard board
insulation and place under boiler between legs
then add 1x10 between legs to hold up
insulation
The boiler is 180 degrees or lower and
the boiler is steaming
Poor burn time
Boiler is up to temperature but little to
no heat in house
Boiler over heats Air leak
Boiler fire does not stay lit Not leaving some coals in burn area
Good wood but does not burn. Only
smolders
Boiler up to temperature but no heat in
house
Poor water circulation Change to a larger pump, ensure return line
Green or soft wood is being used,
Damper is open to far
Poor circulation (A simple test can be
done to determine if this is so: touch the
pex line leaving and returning to boiler.
There should be little or no temperature
difference)
Heat exchanger plugged
Improperly designed installation
Not enough insulation in building
Damper open to far
Water is low in boiler
Aqua-stat malfunction
Ash in ash pan not clean
Blower air way plugged Remove blower and clean air way
Circulation pump failed
comes in on the opposite lower end
Use dry, seasoned hard wood
Adjust damper to be ¼” open at widest point
Change to a larger pump
Clean and add a y-strainer – be sure to use
treatment!
Reduce number of 90’s & T’s used
Add insulation to structure
Make sure loading door is sealed & adjust if
necessary, make sure ash pan is shut
Adjust damper to ¼” open @ widest point
Add water to keep full
Replace Aqua-stat
Leave some coals in burn area
Check the area behind the ash pan to make
sure there is no ash build up that would block
blower air way.
See maintenance section on pump
Boiler water getting rusty Not enough or no boiler treatment Have your dealer or Nature’s Comfort test
Solenoid opens damper but blower
won’t come on
Blower turns on but solenoid does not
open
Loose wire connection
Blower burned out
Loose electrical connection
Solenoid burned out
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your water. Boiler treatment is required for
warranty to be valid! See warranty.
Turn power off and check all wire
connections
Replace blower
Turn power off and check all wire
connections
Replace solenoid
VII. Disclaimer
All installation and operation must follow Federal, Provincial, State and Local codes, ordinances and laws.
Nature’s Comfort boilers are not intended to be used in urban areas.
Nature’s Comfort boilers are not intended to be the only source of heat. Therefore, a backup system should
always be in place and be ready for use.
Nature’s Comfort boilers are not intended to operate under pressure.
All electrical and plumbing should be done by qualified personnel and conform to national, state and local
electrical, plumbing, fire and building codes.
Manufacturer is not liable for damages to personnel or property for misuse, improper installation of equipment or
for knowing Federal, Provincial, State and Local codes, ordinances and laws including local installation codes.
Owner assumes all responsibility for this.
GOING AWAY
When going away during freezing weather and no one will be keeping the boiler going, turn your backup heat
system on, the boiler blower off and keep the circulation pump running. Your boiler will now operate in reverse
being kept above freezing by your backup system eliminating the need to otherwise drain the boiler.
Please keep this manual with all other important papers. The information in this manual is necessary for the
installation, operation and proper use of your boiler. If you should ever have a problem or question please refer to this
manual or call your dealer. Please have your serial number ready. This is found on a silver tag on the back of the rear
access door or stamped into the fire door jamb on the top left. If your dealer does not have the information you need,
request they contact Nature’s Comfort and your dealer will be further educated to provide the best possible customer
service. Please keep in mind that Nature’s Comfort built your boiler but did not install it and has no control over the
installation, the efficiency of the building’s insulation or what is burned in the boiler. www.naturescomfortllc.com
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VIII Warranty Registration Card
(To be mailed in)
All fields must be filled out
Your Name: __________________________________________