Greenwood 100 User manual

Greenwood Hydronic Furnace
MODELS 100, 200, 300
Owner’s Manual
BE SURE TO READ THIS MANUAL AND KEEP IT NEAR THE FURNACE FOR
EASY REFERENCE
For the latest information and manual for your Greenwood Furnace, refer to the “SUPPORT”
section of the Greenwood website: www.GreenwoodFurnace.com
Greenwood furnaces are certified to meet UL-391-1995 and CAN/CSA B366.1-M91 standards
for safety for solid-fuel fired indoor heating appliances
V 4.1
© 2008 Greenwood Technologies, LLC
All Rights Reserved
GREENWOOD TECHNOLOGIES, LLC
13427 NE 20th St, Ste. 120 • Bellevue, WA •98005
800-959-9184
Support: 877-436-6191

TABLE OF CONTENTS
Section Page
Safety Certifications 2
Emissions Certifications 4
Introduction and How the Furnace Works 5
Specifications 7
General Installation 9
Installation requirements summary checklist 9
Unpack and inspect the furnace 10
Unloading and locating the furnace 11
Minimum furnace installation clearances 12
Install the chimney flue 13
Plumb the furnace 13
Wire the furnace 14
Chimney Installation 15
Flue size 15
Connecting to an existing chimney flue 16
Connecting to a new factory-made chimney 18
Supplying makeup air 18
Measuring and adjusting the draft 19
Sources of equipment and information 20
Plumbing Installation 23
Open versus closed systems 21
Flat plate heat exchangers 21
Schematic--Basic open system configuration 22
Schematic--Basic closed system configuration 23
Schematic—Open to closed radiant heating system w/ boil over protection 24
Schematic—Closed system connected to two zones w/o heat exchanger 25
Schematic—Closed system connected to two zones with heat exchanger 26
Schematic—Open system connected to closed forced-air system 27
Schematic—Closed system connected to closed forced-air system 28
Legend of schematic components 29

Wiring and Controls 31
Basic furnace controls and wiring configuration 31
Auxiliary wiring for thermal spike protection 32
Auxiliary wiring for backup heat from the main furnace to boiler 33
Continued on next page…

Power Outages and Boil Over Protection 34
Universal power supply 34
Greenwood fluid management kit 35
Gravity flow system 35
City water 35
Auto-start generator 35
Operating the Furnace 36
Safe practices 36
First startup and cold startup each season 37
Warm start 39
Feeding wood into the firebox 40
What kind of wood to burn 40
Ash removal 43
Maintenance 44
Safe practices 44
Heat transfer fluid 44
Annual shutdown maintenance 44
System flush 44
Troubleshooting 45
Furnace is not heating 45
Creosote or condensation is forming 45
Furnace is over heating 45
Cracks in the firebox refractory 45
Chimney 46
Warranty –Greenwood Furnace Installation Checklist 48
Warranty –Greenwood Furnace Warranty 50

Certifications
© 2008 Greenwood Technologies, LLC Page 2
SAFETY CERTIFICATIONS
OMNI-Test Laboratories, the leading independent test laboratory for wood-burning products, has tested
Greenwood's hydronic wood furnace and certified its compliance with:
U.S. standards for solid-fuel and combination-fuel central and supplementary furnaces (ANSI/UL-
391-1995)
Canadian standards for solid fuel-fired central heating appliances (CSA B366.1-M91)
The Greenwood test report number from OMNI-Labs is 302-S-01-2.
OMNI-Test Laboratories, Inc.

© 2008 Greenwood Technologies, LLC Page 3
V4.1
This page intentionally left blank.

© 2008 Greenwood Technologies, LLC Page 4
V4.1
EMISSIONS CERTIFICATIONS

© 2008 Greenwood Technologies, LLC Page 5
V4.1
INTRODUCTION
Congratulations on your purchase of this wood-fired hydronic furnace from Greenwood Technologies. With
proper installation and maintenance, this US Environmental Protection Agency (EPA) Phase 1 emissions
compliant furnace will provide years of low cost heat for your home.
To insure correct installation and safe operation of your Greenwood hydronic furnace, you should:
1. Hire a Greenwood approved licensed heating contractor to install the furnace and integrate it
with your heating system. This contractor should have experience with installation and operation of
gas, oil, and solid fuel heating appliances and be familiar with local building codes, fire codes and
other regulations.
2. Read this manual and learn how to safely operate and maintain your Greenwood furnace.
How the Greenwood furnace works
The Greenwood furnace produces few emissions and achieves a high level of heating efficiency because of
its unique design. The ceramic firebox supports an internal temperature that allows the furnace to convert
every bit of wood fuel into thermal energy. Then, the unique up and down draft flame path allows the heat
exchanger to absorb the maximum possible energy from the superheated air. This simple, yet sophisticated
design results in a highly efficient, clean burning furnace that will provide years of reliable, low cost heating
for its owner.
To understand how the Greenwood hydronic furnace works, we need to look at the flow of air and wood
gases through the furnace and the transfer of heat from the superheated gases to the thermal transfer fluid
circulating in the internal heat exchange manifold.
Air Flow through the Furnace
1. Heat from the burning fire draws fresh air into the furnace through a mechanically operated air
intake manifold. An aquastat (a thermostat that works in water) opens and closes the damper to
regulate the air entering the firebox and control the rate of burning.
2. As air flows through the firebox, its temperature rises to nearly 2000ºF.

© 2008 Greenwood Technologies, LLC Page 6
V4.1
3. This superheated air rises upwards and then downward as it follows a path toward the furnace‘s
exhaust vent. In the middle of this flame path is an internal heat exchange manifold with heat
transfer fluid flowing through it. This fluid absorbs thermal energy from the superheated air.
4. By the time the exhaust air reaches the vent, most of its thermal energy has been absorbed, but there
is still one last thing it does. Before exiting the furnace, the exhaust gas flows past the air intake
tubes and preheats the incoming air. The final temperature of the escaping gas is only 350º F.
Fluid Flow through the Furnace
1. The Greenwood furnace uses a mixture of water and propylene glycol as a heat transfer fluid. Glycol
is a non-toxic solution that works like the antifreeze in your car to prevent corrosion and freezing.
2. A pump pushes fluid through an internal heat exchange manifold located in the flame and exhaust
path of the furnace, which absorbs heat from the combustion gases. The fluid exits the internal
manifold at about 180ºF.
3. The fluid flows past an aquastat (water thermostat) that regulates the burn rate of the furnace, to the
home heating system.
4. The heated fluid provides warmth to your home, garage, basement and other structures; preheats
your domestic hot water; and/or heats your pool.
5. Having transferred the heat to the home system, the fluid repeats its path through the internal
manifold.

© 2008 Greenwood Technologies, LLC Page 7
V4.1
SPECIFICATIONS
Model:
Greenwood 100
Greenwood 200
Greenwood 300
Furnace Output (BTU/hour)
100,000 BTU
200,000 BTU
300,000 BTU
Heating Capacity*
Up to 4,000 ft2
Up to 8,000 ft2
Up to 12,000 ft2
Furnace dimensions
32”w x 52”h x 48”d
42”w x 52”h x 48”d
52”w x 52”h x 48”d
Max log length (door width)
18 inches
28 inches
38 inches
Max log diameter (door height)
16 inches
16 inches
16 inches
Approximate Weight
2,350 pounds
3,000 pounds
3,700 pounds
Firebox Volume
19”w x 32”h x 24”d
8.4 cubic feet
29”w x 32”h x 24”d
12.9 cubic feet
39”w x 32”h x 24”d
17.3 cubic feet
*Heating capacity depends on many factors including home design, construction quality, insulation quality, local
climate, type of wood burned, etc. Square footage based sizing is unreliable, always base sizing on sustained
output and heat loss calculations.

© 2008 Greenwood Technologies, LLC Page 8
V4.1
This page intentionally left blank.

© 2008 Greenwood Technologies, LLC Page 9
V4.1
INSTALLATION
Your Greenwood furnace should be installed by a Greenwood approved heating contractor who is thoroughly
familiar with gas, oil, and solid fuel heating appliances. Also, be sure to comply with local building codes,
fire codes and other regulations when installing the furnace.
Installation Requirements Summary Checklist
These are guidelines, please refer to appropriate manual sections for further details:
General
Thoroughly read this entire manual and follow all instructions.
Hire a licensed contractor with certified Greenwood installer training and experience in design and
installation of hand-fired hydronic heating systems to install your Greenwood hydronic furnace.
Use caution when moving this furnace. Greenwood furnaces weigh between 2,500 and 4,000 pounds
and serious injury can occur if you do not have the proper equipment and experienced manpower
available.
Comply with local building codes, fire codes and other regulations when installing this furnace and
observe minimum clearances to combustible surfaces.
DO NOT install the furnace in a mobile home or trailer. Instead, install the furnace outside in a
covered enclosure and pipe the hot water into the mobile home.
Chimney and Venting
Make sure to identify sources of make-up air in the room where the furnace is located. The
Greenwood furnace, exhaust, fans and other appliances all draw air from the room. Be certain there
is an adequate source of fresh air to offset these demands or you may create negative pressure in the
room and starve the furnace of combustion resulting in draft problems in your flue.
Connect the furnace to a properly installed and operating chimney and vent it to the outside. Use an
approved masonry or a UL 103 HT and ULC S629 Listed Residential Type and Building Heating
Appliance Chimney.
DO NOT vent the furnace to another room or inside a building. Install with a dedicated chimney
only. Do Not share the chimney with another appliance. Be sure your chimney is safely constructed
and in good repair. Before furnace installation, have the chimney inspected by a qualified inspector.
DO NOT connect the furnace to an aluminum Type B gas vent
DO NOT operate the furnace with a draft of less than 0.05‖WC (12.45 Pa) or more than 0.07‖WC
(17.44 Pa).
Plumbing and Controls
Be sure to provide thermal spike protection for the furnace (see ‗Wiring and Controls‘).
Provide for loss of power by installing battery backup, fluid management tank, gravity dump zone,
or other solution.
As with all modern, high efficiency boilers, make sure that a 3 way thermostatic mixing valve set at
140° is properly installed to ensure that the temperature of water returning to the furnace is above
136°. This will prevent condensation that will lead to poor performance and potential damage.
Ensure proper fluid flow rates through the Greenwood Furnace and Delta T (temperature differential)
of 20°. Specified gallon per minute flow rates for the Greenwood Furnace models are: 10 gpm
(Model 100), 20 gpm (Model 200), and 30 gpm (Model 300).

© 2008 Greenwood Technologies, LLC Page 10
V4.1
1. Unpack and inspect the furnace
When the furnace is delivered, inspect it for visible damage. If damaged, list the issues and date on the
shipping document and ask the driver sign it. Check the packing slip for a list of items shipped with the
furnace (some of the items will be found stowed inside the firebox). If you observe any damage or find any
items missing, please you‘re your Dealer or Greenwood Customer Service for instructions (877-436-6191).
Each unit is wired for 115 volt operation and plumbed with a temperature gauge, aquastat, air vent, drain
valve, and air intake damper motor.
Items packed inside the firebox include:
-Leather hearth gloves
-Owner‘s Manual
-Additional parts such strap-on aquastat or other items ordered with the furnace.
Additional parts required for system installation may arrive with the furnace or be shipped separately. These
may include parts for an ―Open System‖ or a ―Closed System,‖
Model 100 Greenwood Furnace
Note: This is a representative diagram of furnace components. Actual parts and configuration may vary.
This diagram does not include standard installation components such as mixing valve, pressure release
valve, pump, expansion tank, or balancing valve, etc.

© 2008 Greenwood Technologies, LLC Page 11
V4.1
2. Unloading and locating the furnace
CAUTION: These units are heavy! The Model 100 weighs about 2,450 pounds; the Model
200 weighs about 2,830 pounds; and the Model 300 nearly 3,700 pounds. Make sure you
have proper equipment and sufficient manpower to prevent injury or damage when
unloading and locating the furnace unit
When moving the furnace from the bottom, use a forklift with 5,000 lb or greater capacity and 5-6 ft. forks.
Center the forks under the chassis, with the forks spread to minimize the overhang on either side. Move the
loader as close to the furnace as possible without contacting
the rack or the front of the loader. Pick the furnace up by
keeping it level and lifting only as high as necessary to
move the unit. Do not accelerate or stop the loader
suddenly. Make slow and stable maneuvers with the
furnace on the forks.
CAUTION: Never stand in the path of the load
when lifting or moving the furnace, whether lifting
from the bottom or the top.
When lifting the furnace from the top, use the two forged
lifting eyes located at the top corners diagonal from one
another. These eyes are rated for a straight pull, which means they are to be used in a VERTICAL LIFT
ONLY. The use of a load spreader, or ―strongback‖ is required to properly rig the furnace for top lifting. The
lifting eyes must not be joined with slings or cables in any configuration that would pull and bend the lifting
eyes, or in any load direction other than vertical. Failure to observe this safe lifting requirement could result
in damage to the furnace or serious injury to personnel. Specified spreader bar lengths for Greenwood
Models 100, 200, and 300 are 54‖, 60‖, and 67‖ respectively.
WARNING: If you are not a professional rigger or do not have experience with portable
cranes, winches, hoists, or other lifting devices, and you have determined that a top lift is
required to place the furnace in its installed location, you should use an equipment or
machinery-moving company to set the furnace in its final location. If the furnace is
dropped, the refractory ceramic firebox can be damaged. An experienced rigger can ensure
that the furnace is safely lifted and set in place without damage.
The Greenwood furnace is certified for safety as an INDOOR APPLIANCE, so you can install it in a walk
out basement, shed, out-building or almost any location where the unit is sheltered from the weather and
insulated from freezing intake air. DO NOT install this furnace in a mobile home or trailer. As with any
furnace operated indoors, install a carbon monoxide monitor in the room where the furnace is installed.
NOTE: Installation must be completed in accordance with National Fire Protection
Association (NFPA) installation standards No. 89M, 90B, 211, 70 (National Electrical Code)
and Uniform Mechanical Code 913, 6-4 in states where applicable.
Place the furnace on a non-combustible surface, such as solid concrete or masonry. When deciding where to
place the unit, consider the location of your chimney, access to electricity, and the convenience of retrieving
and loading wood. In garages, the National Fuel Gas Code requires that the lowest point of ignition be
elevated no less than 18 inches above the floor, except where furnaces are installed in separate, enclosed
space and where combustion air is taken from outside the garage.
Check for clearances. Greenwood furnaces are tested to UL (Underwriters Laboratories) and CSA (Canadian
Standards Association) standards of safety for indoor appliances. As a result, you can install your furnace
with a minimum separation between the furnace and combustible surfaces. The following table and
illustrations show the minimum clearances to combustible materials.

© 2008 Greenwood Technologies, LLC Page 12
V4.1
Minimum Installation Clearances (Side View)
Minimum Installation Clearances (Top View)
Minimum Clearance to Combustible Materials
Furnace Face
Min Clearance1
Notes
Right and left sides
12 inches (30 cm) (all models)
Rear
36 inches (90 cm) (all models)
Includes allowance for flue
Front
36 inches (90 cm) (Model 100/200)
48 inches (120 cm) (Model 300)
Allows firebox door to fully open
Top
33 inches (85 cm) (all models)
Bottom
0 inches (0 cm)
Use non-combustible surface
1Minimum distance from a combustible surface
NOTE: Installation of this furnace must comply with the latest edition of NFPA 211 for
reduced clearances and/or your local building code rulings (use whichever minimum
dimensions are LARGEST).
Note: If using 24
gauge flue
piping instead of
metalbestos or
double/triple
wall flue
material, a
minimum 18”
between flue
pipe and back
wall is required.

© 2008 Greenwood Technologies, LLC Page 13
V4.1
3. Install the chimney flue
Refer to the ―CHIMNEY INSTALLATION‖section for detailed instructions. Proper installation of the
chimney flue is critical to the performance of your Greenwood furnace. The majority of problems
encountered after installation are attributable to a flue that is improperly sized or otherwise provides
inadequate draft to the furnace.
NOTE: The draft of the chimney flue must be .05” to .07” W.C. (12.45 to 17.44 Pa)
measured near the exhaust collar of the furnace. There must also be adequate sources of
make-up air for the room where the furnace is installed. See “CHIMNEY INSTALLATION”
instructions for more information.
4. Plumb the furnace
You can plumb your Greenwood furnace to meet almost any heating need in the home. You can:
Supplement an existing hydronic or forced-air central heating system,
Produce domestic hot water;
Heat your home, greenhouse, garage, outbuilding, basement or swimming pool.
NOTE: Proper plumbing of your Greenwood furnace requires the expertise of a plumber
or HVAC professional that is Greenwood approved.
Plumb the furnace for either open system or closed system operation (see ‗PLUMBING INSTALLATION
section). The furnace is leak-tested at the factory during final assembly, and the heat transfer fluid drained for
shipment. The recommended fluid solution is a mix of 30% propylene glycol to 70% water, unless you are
located in a very cold climate, or you plan to leave the furnace unused for a long period of time. A 30%
solution of propylene glycol is adequate to lower the freezing point to 7º F and raise the boiling point to
217ºF.
CAUTION: DO NOT use ethylene glycol-based (automotive antifreeze) coolant in your
Greenwood Hydronic Furnace or in your home‟s heating system. Always use propylene
glycol-based coolants rated for a heat application. If your local HVAC supplier does not
have this material, Greenwood Technologies will help you find a local source. Do not use
any coolant other than propylene glycol. This solution is non-toxic to animals and
humans.
CAUTION: Be careful not to spill fluid on the top of the furnace. It could leak around the fill port
and saturate the firebox insulation inside. Wrap a towel or other absorbent material around the
fill port to catch any spills.

© 2008 Greenwood Technologies, LLC Page 14
V4.1
5. Wire the furnace
Your Greenwood furnace arrives pre-wired for 115 volt, 60-cycle operation. The basic wiring consists of
plugging the power cord into an available outlet or, if required by local code, a dedicated 20-amp circuit with
a circuit protector device located in a convenient place near the furnace.
Additional wiring is required by your installer to integrate the furnace into your existing home heating
system. See the ―WIRING AND CONTROLS‖section for more information.
WARNING: All electrical wiring for your Greenwood furnace must conform to the National
Electrical Code and all local building codes and ordinances. Turn off electric power at the
circuit protector box before making any line voltage connections. Do not plug the furnace in
until the furnace is fully installed and the proper fluid has been added.

Chimney Installation
© 2008 Greenwood Technologies, LLC Page 15
V4.1
CHIMNEY INSTALLATION
A chimney performs two functions: it removes smoke and flue gases from the furnace, and it provides
―draft‖ for the fire. Draft is the term used to describe the suction that occurs when hot air rises and creates a
vacuum in the firebox. That vacuum draws fresh air into the firebox and feeds combustion of the wood. No
furnace can operate properly without adequate draft.
NOTE: The Greenwood Furnace requires draft measuring between .05” and .07” WC
(water column) (12.45 –17.44 Pascals), measured with a manometer or similar device.
Draft of less than .05” will starve the fire of oxygen and cause it to burn dirty (i.e.,
produce smoke and creosote). Draft of more than .07” will feed too much oxygen to the
fire, causing it to over-fire and burn at less than optimum efficiency. Draft should be
measured with a manometer following the prescribed warm up period. For specific
measurement guidelines, see p. 18 „Measuring and Adjusting the Draft of the Flue.‟
NOTE: The following instructions are guidelines only. A qualified HVAC contractor should
determine the specific chimney requirements for your furnace installation and insure that
it complies with local building codes and ordinances.
Flue Size
The chimney flue is a vital part of your furnace installation. A properly built and maintained masonry
chimney or factory-built flue will assure a consistent draft under a variety of weather conditions.
NOTE: The furnace must connect to a code-approved masonry chimney with a flue liner
or an appropriately sized factory-built chimney, which complies with requirements for
Type HT (High Temperature), all fuel chimneys in the standard UL 103 or CAN/ULC-S629.
Flue Diameter
The outlet collar on all Greenwood furnace models is 8 inches. The model number of your Greenwood
furnace determines the minimum size of the connecter pipe and flue. For the Model 100 and 200
Greenwood furnaces, a flue reducer is required to connect the 8-inch outlet collar to the appropriately
sized connector pipe.
Furnace
Min Flue Diameter
Model 100
6 inches (150mm)
Model 200
7 inches (180mm)
Model 300
8 inches (200mm)
Flue Height
The flue must be tall enough to draw, which typically means at least 12-15 feet tall (3.66m) [note: Add one
foot (0.3m) to this minimum for each 1000 feet above sea level]. If you cannot control the height of the flue,
it may be necessary to install a draft inducer fan (see ―Measuring and Adjusting the Draft‖ later in this
section).

Chimney Installation
© 2008 Greenwood Technologies, LLC Page 16
V4.1
Connecting to an Existing Chimney Flue
You may connect the Greenwood furnace to an existing flue or chimney subject to the following conditions:
1. A qualified professional has inspected, repaired (if necessary), thoroughly cleaned and determined
the chimney is suitable for use with a residential heating appliance that burns solid fuel.
2. If possible, avoid using exterior chimneys (i.e., a chimney with one or more walls exposed to the
outside below the roofline). If it is necessary to use an exterior chimney, the chimney flue size area
must not exceed two times the minimum flue area for the furnace. If an internal chimney is used, the
chimney flue size area must not exceed three times the minimum flue area for the furnace.
Furnace
Min Flue
Diameter
Max Flue Area
Internal Chimney
Max Flue Area
External Chimney
Model 100
6 inches (15 cm)
85 in2(177 cm2)
56 in2(116 cm2)
Model 200
7 inches (18 cm)
116 in2(241 cm2)
77 in2(160 cm2)
Model 300
8 inches (20 cm)
151 in2(314 cm2)
101 in2(208 cm2)
3. If your chimney flue exceeds the maximum area allowed, it must be lined with a suitable flue liner
that complies with the requirements of Chapter 11 of NFPA 211 3-1.2 -- Standards for Chimneys,
Fireplaces, Vents and Solid Fuel-Burning Appliances.
4. The chimney or flue should be at least 12 feet tall and sized correctly for the Greenwood Furnace
model installed.
5. Do not share a flue with another furnace, appliance or fireplace. Do not use a flue that already
provides make-up air to the cellar or basement.
6. Tightly close the cleanout opening in the base of the chimney.
Connector Flue Pipe
The connection between the furnace and the chimney must be at least 24-gauge stovepipe and elbows (not
included with furnace). Maintain a clearance of at least 12 inches between the connector and combustible
surfaces as shown on the following illustration.
Minimum Installation Clearances (Side View)
Chimney
Note: If it is
necessary to use
an exterior
chimney, the
chimney flue size
area must not
exceed two times
the minimum flue
area for the
furnace. If an
internal chimney
is used, the
chimney flue size
area must not
exceed three
times the
minimum flue area
for the furnace.
Note: If using 24
gauge flue piping
instead of
metalbestos or
double/triple wall
flue material, a
minimum 18”
between flue
pipe and back
wall is required.

Chimney Installation
© 2008 Greenwood Technologies, LLC Page 17
V4.1
NOTE: Installation of this furnace must comply with the latest edition of NFPA 211
for reduced clearances and/or your local building code rulings -- use whichever
minimum dimensions are LARGEST.
Observe the following rules when installing the connector pipe.
1. Where possible, use only corrugated (non-adjustable) elbows. These are more airtight and less likely
to break. Use 90-degree elbows only as required and never more than two (they reduce the draft of
the chimney).
2. Make sure all horizontal runs of connector pipe have a minimum outward rise of 1/4‖ per horizontal
foot.
3. If the connector stovepipe must go through a combustible wall before entering the masonry chimney,
consult a qualified mason or chimney dealer. The installation must conform to local building and fire
codes and latest edition of NFPA 211.
4. Insert the crimped end of the stovepipe inside the furnace outlet collar. Install additional pipe and
elbows with the crimped end towards the furnace.
5. Seal the connector pipe to the chimney with furnace cement.
6. Securely support the connector pipe and fasten joints with a minimum of three sheet metal screws or
rivets per joint.
7. In all cases, follow the chimney manufacturer‘s instructions for installation.
When attaching the connector pipe to the chimney, do not push it into the chimney (it may plug the chimney
and impede the draft). The following illustration shows proper installation.
Installation of the Connector Pipe into an Existing Chimney