Camus Hydronics MFH060 Setup guide

99-0073
Rev. 00
INSTALLATION OPERATION
AND SERVICE MANUAL
MODULATING MICOFLAME SERIES
GAS FIRED RESIDENTIAL AND COMMERCIAL COPPER TUBE
BOILERS
FOR HYDRONIC HEATING
Non-Condensing Models; MFH060, 100, 150, 200, 250, 300, 400, 500, 600
Condensing Models; MFH062, 102, 152, 202, 252, 302, 402, 502, 602
HOT WATER SUPPLY
Non-Condensing Models; MFW060, 100, 150, 200, 250, 300, 400, 500, 600
Condensing Models; MFW062, 102, 152, 202, 252, 302, 402, 502, 602
WARNING: If the information in these instructions is not
followed exactly, a fire or explosion may result causing
property damage, personal injury or death
•Do not store or use gasoline or other flammable
vapours and liquids in the vicinity of this or any other
appliance.
•WHAT TO DO IF YOU SMELL GAS
oDo not try to light any appliance,
oDo not touch any electrical switch; do not use any
phone in your building,
oImmediately call your gas supplier from a
neighbour’s phone. Follow the gas supplier’s
instructions,
oIf you cannot reach your gas supplier, call the fire
department.
•Qualified installer, service agency or the gas supplier
must perform installation and service.
To the installer: After installation, these instructions must be
given to the end user or left on or near the heater.
To the End User: This booklet contains important information
about this heater. Retain for future reference.
CAMUS HYDRONICS LTD.
6226 Netherhart Road, Mississauga, Ontario, L5T 1B7

Table of Contents
1 GENERAL INFORMATION............................................................................................................1
2 BOILER LOCATION.......................................................................................................................2
3 PROVIDE AIR FOR COMBUSTION AND VENTILATION..............................................................3
4 ELECTRICAL WIRING...................................................................................................................4
5 MODULATION SEQUENCE..........................................................................................................4
6 GAS SUPPLY AND PIPING...........................................................................................................5
7 VENTING.......................................................................................................................................6
7.1 OUTDOOR VENTING ...................................................................................................................8
7.2 SIDEWALL VENTING....................................................................................................................9
7.3 OUTDOOR AIR KIT.......................................................................................................................9
7.4 FILTER KIT ...................................................................................................................................9
7.5 STANDARD VENTING..................................................................................................................9
7.6 VENTING FOR CONDENSING APPLICATION...........................................................................10
8 ACCESSORIES...........................................................................................................................11
8.1 WATER FLOW SWITCH (shipped loose)....................................................................................11
8.2 LOW WATER CUTOFF (If Equipped)..........................................................................................11
8.3 RELIEF VALVE (shipped loose)..................................................................................................11
9 FREEZE PROTECTION...............................................................................................................12
10 WARNING REGARDING CHILLED WATER SYSTEMS..............................................................12
11 PIPING OF BOILER TO SYSTEM ...............................................................................................13
12 PLACING BOILER IN OPERATION.............................................................................................14
13 IGNITION SYSTEM SAFETY SHUT-OFF DEVICE......................................................................14
14 LOW WATER TEMPERATURE SYSTEMS .................................................................................15
15 INSTANTANEOUS WATER HEATER..........................................................................................16
16 CONDENSING HEAT RECOVERY MODULE (CHRM)................................................................16
17 INSTRUMENTATION AND CONTROLS......................................................................................20
17.1 SAFETY CONTROLS..................................................................................................................20
17.2 CONTROL PANEL......................................................................................................................20
17.3 SETTING THE APPLIANCE TEMPERATURE CONTROLLER...................................................21
17.4 MODES OF OPERATION ...........................................................................................................21
18 MICOFLAME CONTROL PANEL.................................................................................................28
18.1 GENERAL SYMBOL DESCRIPTION ..........................................................................................29
18.2 MODE 1 & 2: SETPOINT OPERATION: VIEW DISPLAY............................................................30
18.3 MODE 1 & 2: SETPOINT OPERATION: ADJUST DISPLAY .......................................................31
18.4 MODE 3: DEDICATED DOMESTIC HOT WATER OPERATION: VIEW DISPLAY......................32
18.5 MODE 3: DEDICATED DOMESTIC HOT WATER OPERATION: ADJUST DISPLAY.................33
18.6 MODE 4 & 5: OUTDOOR RESET OPERATION: VIEW DISPLAY...............................................34
18.7 MODE 4 & 5: OUTDOOR RESET OPERATION: ADJUST DISPLAY..........................................35
18.8 MODE 6 & 7: EXTERNAL TARGET TEMPERATURE INPUT OPERATION: VIEW DISPLAY.....36
18.9 MODE 6 & 7: EXTERNAL TARGET TEMPERATURE INPUT OPERATION: ADJUST DISPLAY 37
18.10 MODE 8: EXTERNAL DRIVE OPEATION: VIEW DISPLAY........................................................38
18.11 MODE 8: EXTERNAL DRIVE OPEATION: ADJUST DISPLAY ...................................................39
18.12 ERROR MESSAGES...................................................................................................................39
19 PILOT AND MAIN BURNER FLAMES.........................................................................................41
19.1 MAIN BURNER ...........................................................................................................................41
19.2 PILOT BURNER..........................................................................................................................44
20 OPERATION AND SERVICE.......................................................................................................44
20.1 PRE-START CHECKLIST...........................................................................................................44
20.2 START-UP ..................................................................................................................................45

20.3 SERVICE.....................................................................................................................................50
21 LIGHTING INSTRUCTIONS ........................................................................................................50
22 TROUBLESHOOTING GUIDE.....................................................................................................51
23 TYPICAL GAS TRAIN..................................................................................................................52
24 ELECTRICAL DIAGRAMS...........................................................................................................53
24.1 MF 60 - 300 INTERNAL WIRING CONNECTION DIAGRAM ......................................................54
24.2 MF 400 - 600 INTERNAL WIRING CONNECTION DIAGRAM ....................................................55
24.3 MF 60 – 1000 INTERNAL WIRING LADDER DIAGRAM.............................................................56
25 EXPLODED VIEW .......................................................................................................................57
26 MICOFLAME REPLACEMENT PARTS LIST...............................................................................58
WARRANTY................................................................................................................................................61

1
1 GENERAL INFORMATION
Camus Hydronics proudly introduces the Modulating MicoFlame series of water heaters / hydronic
boilers. The Modulating MicoFlame is a fan assisted appliance based on a push through design which
offers several venting options. Heat output is controlled by an adjustable ratio air/gas control valve. The
Modulating MicoFlame Models are capable of modulating from 100% down to 35% of rated input. These
gas-burning appliances are thoughtfully designed for easy operation and maintenance. We are confident
that you will come to appreciate the benefits of our product.
The installation of this heater must conform to the requirements of the authority having jurisdiction or, in
the absence of such requirements, to the latest or current as amended National Fuel Gas Code, ANSI
Z223.1 or current CAN/CGA B149 Installation Codes. All electrical wiring must be done in accordance
with the requirements of the authority having jurisdiction or, in the absence of such requirements, with the
National Electrical Code, ANSI/NFPA 70 or the Canadian Electrical Code Part I, CSA C22.1 Electrical
Code.
Vent installations must be in accordance with Part 7, Venting of Equipment, of the latest or current as
amended National Fuel Gas Code, ANSI Z223.1, or Section 7, Venting Systems and Air Supply for
Appliances, of the current CAN/CGA B149, Installation Codes and applicable provisions of the local
building codes.
When required by the authority having jurisdiction, the installation must conform to the Standard for
Controls and Safety Devices for Automatically Fired Boilers, ANSI/ASME CSD-1.
The qualified installer shall instruct the end user in the safe and correct operation of this appliance and
shall ensure that the heater is in safe working order prior to leaving the job site.
WARRANTY:
Factory warranty shall apply only when the boiler is installed in accordance with local plumbing
and building codes, ordinances and regulations, the printed instructions provided with it and
good industry practices.
Excessive water hardness causing a lime build-up in the copper coils or tubes is not a fault of the
boiler and is not covered by warranty. Consult the factory for recommendations for use in hard
water areas.
Using or storing corrosive chemicals in the vicinity of this boiler can rapidly attack the copper
tubes and coils and voids warranty.
The primary heat exchanger of this boiler is intended to operate under non-condensing
conditions. Inlet temperatures must be maintained at 130°
°°
°F or higher. Warranty is void if the
primary heat exchanger is allowed to operate in condensing mode.
Damage caused by freezing or dry firing voids warranty.
This boiler is not to be used for temporary heating of buildings under construction.

2
2 BOILER LOCATION
Install this boiler in a clean, dry location with adequate air supply and close to a good vent connection. Do
not locate this boiler in an area where it will be subject to freezing.
The boiler is suitable for installation on combustible flooring and should be located close to a floor drain in
an area where leakage from the boiler or connections will not result in damage to the adjacent area or to
lower floors in the structure. If necessary a suitable drain pan should be installed under the boiler.
If the boiler is installed above the level of the building’s radiation system, a low water cutoff device must
be installed in the boiler outlet at the time of installation. Some local codes require the installation of a low
water cutoff on all systems.
Locate the boiler so as to provide adequate clearance for inspection and service all around the unit. It is
recommended that 24” be provided for the top and sides and 48” for the front. This boiler is suitable for
alcove installation with minimum clearances to combustibles as follows:
Table 1: Clearance to Combustibles
TOP: 12”
SIDES: 12”
REAR: 12”
VENT: 6”
FLOOR: 0”
For boiler’s dimensions see Figure 1 and Table 2
Figure 1: Appliance Dimensions

3
Table 2: Appliance Dimensions, (inches)
B' Dia. Venting E' Dia.
Model 'W'
Water
Connection
Gas
Connection
Outdoor
Sidewall or
Condensing
Standard
Air Inlet
MFNH060 18 3/4 1 1/2 1/2
3
3
3
3
MFNH100 18 3/4 1 1/2 1/2
3
3
4
3
MFNH150 18 3/4 1 1/2 1/2
3
3
4
3
MFNH200 18 3/4 1 1/2 3/4
4
4
5
4
MFNH250 25 1 1/2 3/4
4
4
5
4
MFNH300 25 1 1/2 3/4
5
5
6
5
MFNH400 31 1/2 2 1
5
5
6
5
MFNH500 31 1/2 2 1
6
6
7
6
MFNH600 36 1/2 2 1
6
6
7
6
3 PROVIDE AIR FOR COMBUSTION AND VENTILATION
Provisions for combustion and ventilation air must be in accordance with:
•Section 5.3. Air for combustion and Ventilation, of the latest or current as amended National Fuel
Gas Code, ANSI Z223.1, or;
•Sections 7.2, 7.3 or 7.4 of CAN/CGA B149 Installation Codes, and;
•Applicable provisions of the local building codes.
The operation of exhaust fans, compressors, air handling units etc. can rob air from the room, creating a
negative pressure condition leading to reversal of the natural draft action of the venting system. Under
these circumstances an engineered air supply is necessary.
If the heater is to be installed near a corrosive or potentially corrosive air supply, the heater must be
isolated from it and outside air should be supplied as per code.
Potentially corrosive atmospheres will result from exposure to permanent wave solution, chlorinated
waxes and cleaners, chlorine, water softening chemicals, carbon tetrachloride, halogen based
refrigerants, Freon cleaning solvents, hydrochloric acid, cements and glues, masonry washing materials,
antistatic fabric softeners, dry cleaning solvents, degreasing liquids, printing inks, paint removers, etc.

4
4 ELECTRICAL WIRING
All electrical wiring to the boiler must be electrically bonded to ground in accordance with the
requirements of the authority having jurisdiction or, in the absence of such requirements, with the National
Electrical Code, ANSI/NFPA 70 or the Canadian Electrical Code Part I, CSA C22.1, Electrical Code.
Provide disconnecting means of sufficient rating within sight of the boiler. These heaters require an 115V,
60Hz supply. Depending on the pump used, a 15-amp breaker is usually sufficient.
Electrical connections must be made so that the circulator will operate before the gas valve can open. At
no time may the control system allow the burner to fire without water flowing in the system.
Use minimum 18-gauge conductor for 24-volt field wiring to boiler. Splicing of wires is not recommended.
Use sealed tight conduit suitable for outdoor use for outdoor installations. Use terminal strip provided
inside control panel for low water cut-off and remote controller. Refer to wiring diagram provided with
boiler.
5 MODULATION SEQUENCE
Models 60 through 300 are supplied with 2 fans. The modulating fan is connected to the burner box and
the single speed fan is used to provide combustion and cooling air to the space below the combustion
chamber. Models 400 through 600 are supplied with only one modulating fan which pressurizes the space
below the combustion chamber and feeds air to the venturi connected to the air/gas mix tube.
Before the appliance can light off, the air proving switch must be closed and the pilot must be lit. The
blocked flue switch is normally closed and opens only under blocked air or blocked flue conditions. All
models are supplied with a single burner.
Each MicoFlame is supplied with the appropriate wiring diagram showing the sequence provided as well
as any special controls or options requested.
When converting multiple MicoFlame appliances to an external sequencing control each modulating
heater can be regarded as one stage. In this way the sequencer will lead/lag or rotate the boilers
properly. One option (Mode 8 on the BTC 1) allows the remote controller to initiate and modulate the
boiler with a single 0-10V analog signal. Refer to Table 7 for details.
Pre-purge
BTC 1 Modulation control activates the pre-purge cycle for 20 seconds before trial for ignition.
Ignition Trial
On proof of air flow, the air proving switch closes and energizes the ignition module. The module first
initiates a self check and then starts the pilot ignition sequence. The modulating sequence begins with the
modulating fan ramping down to ignition speed. The safety shutoff valve opens, which allows gas to flow
to the pilot burner. At the same time, the electronic spark generator in the module produces 10,000 Volt
spark pulse output. The voltage generates a spark at the igniter that ignites the pilot. If the pilot does not
light, or the pilot flame current is not at least, on average, 1.5 µA and steady, the module will not energize
the combination valve and the main burner will not light. The ignition module provides 100% gas shutoff,
followed by retry for ignition. If required (e.g. CSD-1) a module with lockout feature can be provided.
Main Burner
When the pilot flame is established, a flame rectification circuit is completed between the sensor and the
burner ground. The flame sensing circuit in the ignition module detects the flame current, shuts off the
spark generator and energizes the combination control which is a one to one air/gas ratio control valve.

5
As the modulating fan ramps up, gas input is adjusted accordingly to match the airflow. When the call for
heat ends, the valve is de-energized, and the fan modulates off.
Normal Operation
Modulation is controlled from the Boiler Temperature Controller. The modulating fan is equipped with an
electrically commutated DC motor which responds to a PWM signal.
The control provided with the Modulating MicoFlame allows remote control with an analog signal of 4-
20mA or 2-10VDC.
Demand Satisfied
The BTC 1 senses that the boiler target temperature was reached and de-energizes the stage contact.
Control Alarms
High limit or low water flow will de-energize all gas valves, and the blower. Condition indicators are visible
on the control panel. Each burner/blower set is provided with its own air pressure switch. If a low air
pressure condition is present, power will not be supplied to the ignition module. The blower will remain on
and the air indicator will remain on for as long as there is a call for heat. If the safety proving sequence
does not proceed to completion, the first safety light to remain off will indicate the cause of the problem.
All other lights below the problem indicator light will also remain off.
6 GAS SUPPLY AND PIPING
This boiler is intended to operate at inlet gas pressures not exceeding ½ PSI (14” W.C.). If higher
pressures are present, consult the gas company for correction.
When pressure testing the gas supply piping at pressures above ½ PSI, the boiler and its individual gas
shut-off valve must be disconnected from the supply piping.
Provide a trap (drip leg) as close to the heater as possible.
Install a ground joint union and manual shut-off valve in the gas line near the heater to allow easy
removal of the gas control assembly.
Provide gas pressures at inlet to boiler gas train as follows:
Table 3: Gas Pressures to Inlet to Appliance
PROPANE NATURAL
GAS
Minimum Running
(inches W.C.) 10 4
Maximum Lockup
(inches W.C.) 11 14
The gas supply line must be of adequate size to prevent undue pressure drop and must never be smaller
than the size of the connection on the heater. Sizing based on Table 4 is recommended.
Before operating the boiler, the complete gas train and all connections must be tested using soap
solution.

6
Table 4: Gas pipe size for distance from natural gas meter or propane second stage regulator
DISTANCE FROM NATURAL GAS METER OR PROPANE SECOND STAGE REGULATOR
0-100 FT 100-200 FT. 200-300 FT.Input
Btu/Hr NAT. L.P. NAT. L.P. NAT. L.P.
60,000 ¾” ½“ ¾” ½“ 1“ ¾”
100,000 ¾” ½“ 1“ ¾” 1“ ¾”
150,000 1“ ¾” 1 ¼” 1“ 1 ¼” 1“
200,000 1“ ¾” 1 ¼” 1“ 1 ¼” 1“
250,000 1 ¼” 1“ 1 ¼” 1“ 1 ½“ 1 ¼”
300,000 1 ¼” 1“ 1 ½“ 1 ¼” 1 ½“ 1 ¼”
400,000 1 ¼” 1“ 1 ½“ 1 ¼” 2” 1 ½”
500,000 1 ½“ 1 ¼” 2” 1 ½“ 2” 1 ½“
600,000 1 ½“ 1 ¼” 2” 1 ½“ 2” 1 ½“
7 VENTING
Boilers for outdoor installation are intended to vent using a listed vent cap.
For indoor installations venting must be in accordance with Part 7, Venting of Equipment, of the latest or
current as amended National Fuel Gas Code, ANSI Z223.1, or Section 7, Venting of Equipment and Air
Supply for Appliances, of the CAN/CGA B149, Installation Codes, and applicable provisions of the local
building codes.
Vent connectors serving appliances vented by natural draft shall not be connected into any portion of
mechanical draft systems operating under positive pressure.
Horizontal runs of vent pipe shall be securely supported (approximately every 4 feet) to prevent sagging
and maintain a minimum upward slope of ¼” per foot from the boiler to the vent terminal.
When an existing boiler is removed from a common venting system, the common venting system is likely
to be too large for proper venting of the appliances remaining connected to it .At the time of removal of an
existing boiler, the following steps must be followed with each appliance remaining connected to the
common venting system placed in operation, while the other appliances remaining connected to the
common venting system are not in operation.
a) Seal any unused openings in the common venting system.
b) Visually inspect the venting system for proper size and horizontal pitch and determine that there
is no blockage, restriction, leakage, corrosion or other deficiency, which could cause an unsafe
condition.
c) Insofar as is practical, close all building doors and windows and all doors between the space in
which the appliances remaining connected to the common venting system are located and other
spaces of the building. Turn on the clothes dryers and any appliances not connected to the
common venting system. Turn on any exhaust fans, such as range hoods and bathroom
exhausts, so they will operate at maximum speed, do not operate a summer exhaust fan. Close
fireplace dampers.
d) Place in operation the appliance being inspected. Follow the lighting instructions. Adjust
thermostat so that appliance operates continuously.
e) Test for spillage at the draft hood relief opening after 5 minutes of main burner operation. Use the
flame of a match or candle or smoke from a cigarette.

7
f) After it has been determined that each appliance remaining connected to the common venting
system properly vents when tested as outlined above, return doors, windows, exhaust fans,
fireplace dampers and any other gas-burning appliance to their previous condition of use.
g) Any improper operation of the common venting system must be corrected so that the installation
conforms to the National Fuel Gas Code, ANSI Z223.1 or CAN/CGA B149, Installation Codes.
When resizing any portion of the common venting system, the common venting system should be
resized to approach the minimum size as determined using the appropriate tables in Part 11 of
the latest or current as amended National Fuel Gas Code, ANSI Z223, 1 or CAN/CGA B149,
Installation Codes.
Heat exchanger surfaces and vent piping should be checked every six months for deterioration and
carbon deposits. Remove all soot or other obstructions from the chimney and flue, which might impede
draft action. Replace any damaged or deteriorated parts of the venting system.
A qualified service technician should follow this procedure when inspecting and cleaning the heat
exchanger and vent pipe.
1. Turn off electrical power and close main manual gas shut-off and allow boiler to cool down
2. Remove the vent pipe running to chimney. Remove top outer panel and flue collector access
panel. Check heat exchanger, vent and chimney for obstruction and clean as necessary.
3. Remove burner from boiler and vacuum the heat exchanger. If heat exchanger is excessively
dirty it may be necessary to remove it from the boiler and wash it down with proper detergent
cleaner. Be aware that the combustion chamber base is insulated with ¼” thick ceramic paper. If
this material is damaged or displaced it must be replaced before starting up the boiler.
4. Reinstall parts removed in steps 2 and 3. Be sure that vent pipe has proper pitch and is properly
sealed. Repair or replace any gaskets, which may have been damaged in steps 2 and 3.
5. CAUTION: When replacing the burner be careful to fully engage the back of the burner box into
the retaining slot in the combustion chamber base. Failure to properly locate the burner will result
in erratic flame operation with the possibility of delayed ignition on light off.
6. Restore electrical power and gas supply to boiler.
7. Place boiler in operation using lighting instructions provided.
8. While the boiler is operating, check for flue gas leaks and proper vent operation. Seal any flue
gas leaks using appropriate gasket or sealing material. Carefully examine the flue collector
access panel and heat exchanger ends.
The MicoFlame is a category 1, 85% efficient when supplied as a non-condensing appliance. When
supplied with the optional condensing cartridge, the MicoFlame is 95% efficient and is considered to be a
category II or IV appliance. Three venting options are available for this boiler. See Figure 2 for details.
(Please refer to Table 2 for vent dimensions)

8
Figure 2: Venting Arrangement
7.1 OUTDOOR VENTING
When fitted with the factory supplied rain shield and UL approved vent cap, the MicoFlame is self-venting.
The following applies to outdoor installations:
1. Use only factory supplied rain shields.
2. Periodically check to ensure that air intake and vent cap are not obstructed.
3. Locate boiler at least 3 feet away from any overhang.
4. Locate boiler at least ten feet from building air intake.
5. Avoid installation in areas where runoff from adjacent building can spill onto boiler.

9
7.2 SIDEWALL VENTING
When fitted with the factory supplied vent terminal, the MicoFlame can vent up to 50 equivalent feet.
Elbows can range from 5 to 9 feet in equivalent length depending on centreline radius. See Table 2 for
vent sizes.
Boilers may be installed with either a horizontal sidewall vent or vertical roof top terminal. Terminals differ
with each application. Horizontal lengths over 5 feet must be installed using corrosion resistant stainless
steel. Use single wall vent and seal all joints or use pressure rated double wall vent.
Refer to local codes for proper installation and location of vent terminals.
When using sidewall vent, all vent connector seams and joints must be sealed with pressure sensitive
aluminium tape or silicone sealant as specified by the vent manufacturer. Aluminium tape must meet the
provisions of SMACNA AFTS-100-73 Standard.
When venting through unheated spaces with single wall vent, insulation should be wrapped around the
vent pipe to prevent flue gas condensation inside the vent.
Periodically check to ensure that the vent terminal is unobstructed.
7.3 OUTDOOR AIR KIT
When fitted with the factory supplied air inlet ring and air intake terminal, the MicoFlame can draw outdoor
air over an equivalent length of 50 feet. See Table 2 for vent sizes.
Boilers may be installed with either a horizontal sidewall vent or vertical roof top terminal. Terminals differ
with each application.
The following applies to outdoor air installations:
1. Use only factory supplied air intake terminal.
2. Periodically check to ensure that air intake is not obstructed.
3. Refer to local codes for proper installation and location of vent terminals. Vertical vent terminal
must be at least 3 feet above the highest point where it is located above the roof of a building and
at least two feet higher than any part of the building within a horizontal distance of ten feet
4. Locate the air intake five feet away from the vent discharge. For sidewall venting locate the air
intake below the vent outlet if possible.
7.4 FILTER KIT
A collar sized as per Table 2 is the standard air inlet configuration for the MicoFlame. A filter kit is
available. The filter is washable and accounts for an additional pressure loss of less than 0.05” W.C.
Highly recommended for dusty environments.
The filter kit can also be provided when using the outdoor air kit.
7.5 STANDARD VENTING
The non-condensing 85% efficient MicoFlame is a category 1 appliance and is approved for venting into a
common standard chimney. If chimney height is much greater than 30 feet or if drafts are in excess of
negative 0.05” W.C., it will be necessary to provide a single acting barometric damper directly above the
vent collar. This damper will ensure smooth light off and minimize standby loss through the boiler. Be
sure to position the damper at least 6 “away from the wall of the vent connector.

10
7.6 VENTING FOR CONDENSING APPLICATION
When supplied with the optional condensing cartridge, the MicoFlame is 95% efficient (category II or IV
appliance) which requires the use of a special venting system fabricated from AL29-4C material. Only
venting components listed by a nationally recognized testing agency may be used.
This appliance may be installed with conventional, sidewall or vertical venting. Conventional vented
appliances operate with negative pressure in the vent pipe and require a special vent adapter to increase
the flue outlet diameter. Sidewall and vertically vented appliances operate with positive pressure in the
vent pipe and may be directly connected to the flue outlet without the use of an increaser.
Consult the vent pipe manufacturer’s instructions for minimum clearances to combustible material for vent
components. In the absence of instructions, the minimum clearance to combustible material is six inches.
Consult vent pipe manufacturer’s instructions for proper method of sealing vent pipe sections and fittings.
In the absence of instructions, make sure that pipe and fittings are clean by swabbing with alcohol. Use
Dow Corning 736 or 732 RTV, Polybar # 500 RTV or Sil-bond 4500 or 6500 to seal vent pipe. Do not use
other sealants or adhesives except as expressly permitted by vent manufacturer’s instructions.
Consult vent pipe manufacturer’s instructions for vent system assembly. Follow vent pipe manufacturer’s
instructions if those instructions differ from this section.
Conventional Venting
Multiple condensing appliances may be vented into a common chimney. The chimney must be lined with
AL29-4C and a single acting barometric damper must be provided for each appliance.
A qualified professional using a proven vent-sizing program with input of accurate operating parameters
must properly calculate sizing of the venting system. In applications where flue gas temperatures are
lower than can support a Category II with conventional negative draft, it will be determined at the venting
design stage that a positive pressure will be developed in the vent. It will then be necessary to either
provide separate vents as for Category IV, or to provide an extractor at the chimney outlet in order to
maintain a negative draft in the chimney and allow common venting.
Approval of the installation will be at the discretion of authorities having jurisdiction.
The chimney must be protected from down drafts, rain and debris by using a listed chimney cap.
Sidewall and Vertical Venting
The maximum vent length is 50 equivalent feet. Vent pipe may be run through a vertical or horizontal
chase provided that minimum clearances to combustible materials are maintained.
The vent termination location is restricted as follows:
Minimum 12 inches above grade plus normally expected snow accumulation. Or 7 feet above grade if
located adjacent to public walkways. Do not install over public walkway where local experience indicates
condensation or vapor from the appliance creates a nuisance or hazard. Minimum 3 feet above any
forced air inlet located within 10 feet of vent termination. Minimum 4 feet below, 4 feet horizontally or
above any door window or gravity air inlet. Minimum 4 feet horizontally from electric meters, gas meters,
regulators and relief valves. Use appropriately designed thimbles when passing through combustible
walls or roofs. Install fire stops where vent passes through floors, ceilings or framed walls. The fire stop
must close the opening between the vent pipe and the structure. Locate vent terminal above combustion
air intake terminal (if used) and no closer than 2 feet vertically or horizontally. Vertical venting requires
flashing and a storm collar to prevent moisture from entering the structure. Vertical vent termination must
be at least 2 feet plus the expected snow accumulation above the roof penetration height.

11
8 ACCESSORIES
8.1 WATER FLOW SWITCH (shipped loose)
A water flow switch is shipped loose and is to be installed in the outlet piping on all heating boilers and
hot water supply boilers. The flow switch is wired in series with the 24VAC safety control circuit. A
diagnostic light will be indicated on the control display on a low flow condition.
8.2 LOW WATER CUTOFF (If Equipped)
If this boiler is installed above radiation level, a low water cut-off device must be installed at the time of
boiler installation. Some local codes require the installation of a low water cut-off on all systems.
Electronic low water cut-offs are available as a factory supplied option on all models. Low water cut-offs
should be tested every six months. The normally open switch contact of the low water cutoff is to be wired
in series with the flow switch. A diagnostic light will be indicated on the control display on a low flow
condition. Caution: remove jumper when connecting to 24 VAC circuit.
Figure 3: Low Water Cutoff Electrical Connections
8.3 RELIEF VALVE (shipped loose)
This appliance is supplied with a relief valve sized in accordance with ASME Boiler and Pressure Vessel
Code, Section IV (“Heating Boilers”). The relief valve is to be installed in the vertical position and mounted
in the hot water outlet. No valve is to be placed between the relief valve, and the appliance. To prevent
water damage, the discharge from the relief valve shall be piped to a suitable floor drain for disposal
when relief occurs. No reducing couplings or other restrictions shall be installed in the discharge line. The
discharge line shall allow complete drainage of the valve and line. Relief valves should be manually
operated at least once a year.

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9 FREEZE PROTECTION
•Appliance installations are not recommended outdoors in areas where danger of freezing exists
unless precautions are taken. Maintaining a mixture of 50% water and 50% propylene glycol is
the preferred method of freeze protection in hydronic systems. This mixture will protect the
appliance to approximately -35ºF (-37ºC). To maintain the same temperature rise across the
appliance increase the GPM flow by 15% and the head loss by 20%.
The following example demonstrates the procedure to follow for calculating the revised head for the heat
exchanger when using a water / glycol mixture.
•Given for example that Camus is showing a heat exchanger flow and head loss of 100 gpm @ 10
feet
•Increasing the flow by 15% now results in a head loss of 13 feet at 115 gpm (from B&G system
syzer). At this increased flow Camus now recommends to increase the head loss by 20%.
•The requirement for the heat exchanger with water / glycol mixture will now be 115 gpm @ 15.6
feet. (ie. 1.2 x 13ft. = 15.6 ft.)
•A similar procedure must be followed to calculate the additional head loss in pipe and fittings in
order to arrive at the proper pump selection.
•For Outdoor installations a snow screen should be installed to prevent snow and ice accumulation
around the appliance. Regular inspections should be made to ensure that air intake and vent are
free of snow and ice. Always consider the use of a shelter such as a garden shed in lieu of direct
exposure of the appliance to the elements. The additional protection afforded by the shelter will
help to minimize nuisance problems with electrical connections and will allow easier servicing of
the appliance under severe weather conditions.
10 WARNING REGARDING CHILLED WATER SYSTEMS
When a boiler is connected to an air conditioning system where the same water is used for heating and
cooling, the chiller must be piped in parallel with the boiler. Appropriate flow control valves; manual or
motorized must be provided to prevent the chilled water from entering the boiler. (See Figure 4)
Figure 4: Typical Chilled Water System
When a boiler is connected to heating coils located in air handling units (where they may be exposed to
refrigerated air circulation), the boiler piping system shall be equipped with a flow control valve or other
automatic means to prevent gravity circulation of chilled water through the boiler. Chilled water in the
boiler will create condensate on the boiler tubes, which will collect in the combustion chamber causing
corrosion.

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11 PIPING OF BOILER TO SYSTEM
Check all applicable local heating, plumbing and building safety codes before proceeding.
Be sure to provide unions and gate valves at inlet and outlet to boiler so that it can be easily isolated for
service.
This boiler is of a low mass design, which provides for instant heat transfer. Special attention to water low
rates will ensure that temperature rise does not exceed 35°F (19.4°C). The following Table is provided as
a guide.
For application in areas known to have hard water conditions, contact factory for recommendations.
Table 5: Flow and Pressure Drop at a Given Temperature Rise
Head Loss and Flow Vs Temperature Rise
10 °F 20 °F 30 °F
Model USGPM
∆P ft. USGPM ∆P ft. USGPM ∆P ft.
60 10.2 0.03 5.1 0.01 3.4 0.005
100 17.0 0.07 8.5 0.02 5.7 0.010
150 25.5 0.20 12.8 0.04 8.5 0.030
200 34.0 0.40 17.0 0.08 11.3 0.050
250 42.5 0.65 21.3 0.16 14.2 0.100
300 51.0 1.50 25.5 0.49 17.0 0.190
400 68.0 2.00 34.0 0.55 22.7 0.260
500 85.0 3.00 42.5 0.76 28.3 0.390
600 102.0 4.30 51.0 1.15 34.0 0.550
Figure 5: Typical Boiler Piping to System

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If the boiler is installed above radiation level, it must be provided with a low water cutoff device at the time
of boiler installation. (Available from factory)
To eliminate trapped air, install venting devices at high points in the system as well as in the piping on the
suction of the pump and in the piping on the discharge of the boiler.
Suitable pipe hangers must support the weight of all water and gas piping or floor stands.
Do not allow the boiler to run with inlet water temperature below 130°F.
The boiler must be installed so that the gas ignition system components are protected from water
(dripping, spraying, rain, etc.) During appliance operation and service (circulator replacement, control
replacement, etc.)
12 PLACING BOILER IN OPERATION
The MicoFlame boiler should be installed and started up by qualified personnel.
With the boiler off, open makeup water valve and allow system to fill slowly. Adjust the pressure regulator
to provide at least 15 PSIG in the system when cold.
With all air vents open, run system circulating pump for a minimum of 30 minutes with the boiler off.
Open all strainers in the circulating system and check for debris.
Check liquid level in expansion tank. With system full of water at 15 PSIG, the level of water in the
expansion tank should not exceed ¼ of the total volume with the balance filled with air.
Start up boiler following instructions provided. Operate entire system including pumps and radiation for at
least 1 hour.
Check water level in expansion tank. If level exceeds ½ of tank volume, air is still trapped in system. Shut
down boiler and continue to run pumps.
Within 3 days of start up, recheck all air vents and expansion tank as described above.
13 IGNITION SYSTEM SAFETY SHUT-OFF DEVICE
After initial fill while the main burner is firing, shut off gas to the pilot and clock the time taken for the main
gas valve to shut down. If the safety control is functioning properly, power to the gas valve will be shut off
within 4 seconds of the pilot gas being shut off. If shut down takes longer, ignition control or gas valve
may be defective.

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14 LOW WATER TEMPERATURE SYSTEMS
In applications where the heating system requires supply water temperatures below 130°F (55
o
C), a
bypass line must be installed upstream of the boiler pump so that outlet water can be re-circulated to
raise the inlet temp to a minimum of 130°F (55
o
C). Balancing valves, preferably globe valves are used to
adjust flow (See Figure 6). Alternatively, a thermostatic mixing valve may be supplied (available as a
factory option)
Figure 6: Low Water Temperature System
•Adjustment procedure.
a. Fully open bypass and outlet valves.
b. With boiler running, read inlet temperature after 15 minutes.
c. If the inlet temperature is less than 130°F (55
o
C) slowly close outlet valve until the inlet
temperature climbs to 130°F (55
o
C)
d. If the inlet temperature is greater than 130°F ( 55
o
C) but not greater than 140°F (60
o
C) no
further adjustment is required.
e. Check the inlet temperature after 5 minutes and make final adjustments.

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15 INSTANTANEOUS WATER HEATER
An instantaneous water heater is designed to deliver hot water without the use of a storage tank. It is
suitable for applications with variable load such as restaurants, condominiums, apartments and motels.
(See Figure 7) Call factory for recommendations.
Figure 7: Instantaneous Water Heater Suggested Piping
16 CONDENSING HEAT RECOVERY MODULE (CHRM)
The MicoFlame All Stainless Steel CHRM is mounted in a stainless steel chamber at the rear of the
appliance. The CHRM is constructed from all stainless steel headers and special multiple horizontal
stainless tubes. This CHRM is designed to maximize heat transfer efficiency by fully condensing flue
products and is suitable to resist the low pH of condensate.
The CHRM must be supplied with adequate water flow at all times during operation. Do not operate the
appliance with the CHRM piped out or isolated.
The CHRM is mounted in the discharge of the flue products from the primary heat exchanger. This allows
additional heat to be absorbed from the flue products exhausted from the combustion process. If isolation
valves are provided on the CHRM, the provision of a relief valve at the outlet of the CHRM is
recommended. This valve is to be sized at minimum for 10% of the input of the appliance and is to be
piped to drain.
When cold water supply with temperatures less than 130ºF (55ºC) passes through the CHRM it will cool
the flue products below dew point resulting in the formation of condensation. Furthermore, the volumetric
flow rate of the flue gases will be reduced.
The appliance CHRM loop may be used in condensing mode for a variety of application including
domestic hot water and hydronic space heating. Recommended piping arrangement is shown in Figure 8.
Maximum capacity through the CHRM is summarized in Table 6; flows in excess of 60 GPM must be
bypassed.