Lochinvar Water Heater MFH Iamp;S 02 User Manual

MFH-I&S-02  
INSTALLATION & SERVICE MANUAL  
MANUFACTURED HOME (MOBILE HOME)  
GAS WATER HEATER  
This water heater must be installed in accordance with local codes. In the  
absence of local codes, it must be installed in compliance with The Federal  
Manufactured Home Construction and Safety Stand Title 24 CRF, part 3280 or  
CAN/CSA Z240 MH series, mobile home. In the absence of such standard, The  
Standard for mobile Homes (ANSI/NFPA No. 601B-1977).  
WARNING  
If the information in these instructions is not followed exactly,  
a fire or explosion may result causing property damage, personal  
injury or death.  
This water heater is of the closed combustion type (direct venting) where all the  
combustion air is supplied from the outdoors through the air intake and all  
combusted gas products are vented directly to the outside by means of the  
roof jack. No draft diverter (vent hood) is required for this water heater.  
FOR YOUR SAFETY  
Do not store or use gasoline or other flammable, combustible, or  
corrosive vapors and liquids in the vicinity of this or any other  
appliance.  
Underwriters Laboratories, Inc. has tested a representative sample of this  
water heater design for its safety of operation. The ULA listing of this water  
heater includes the field installation of the following components: roof jack, leg  
enclosure (optional), air intake tube (optional), and heater tie down materials.  
These components for field installation may have been shipped with this heater  
and must be installed according to the instructions (see page 8). No other  
components are approved for use with this water heater.  
WHAT TO DO IF YOU SMELL GAS  
• Do not try to light any appliance.  
• Do not touch any electrical switch; do not use any  
telephone in your building.  
• Immediately call your gas supplier from a neighbor’s  
telephone. Follow the gas supplier’s instructions.  
• If you cannot reach your gas supplier, call the fire  
department.  
This water heater has been designed and certified for the purpose of heating  
potable water. The installation and use of this water heater for any purpose  
other than the heating of potable water may cause damage to the water  
heater, create a hazardous condition, and nullify the warranty.  
Installation and service must be performed by a qualified  
installer, service agency or the gas supplier.  
For your family’s comfort, safety and convenience, we recommend  
this water heater be installed and serviced by a plumbing  
professional.  
CAUTION  
Incorrect operation of this appliance may create a hazard to  
life and property and will nullify the warranty.  
TABLE OF CONTENTS  
GENERAL INFORMATION .......................................................... 1 Do not use this appliance if any part has been submerged in water. You should  
INSTALLATION ..................................................................... 2 contact the plumbing professional who installed the water heater to inspect the  
Locating The Water Heater ...............................................2 appliance and to replace any part of the control system including the combination  
Minimum Clearances......................................................... 2 gas control which has been submerged in water.  
Venting........................................................................... 3  
Combustion Air Supply ..................................................... 3  
Water Connections .......................................................... 4  
Do not store or use gasoline or other flammable, combustible, or  
DANGER  
Gas Connections .............................................................. 5  
Gas Conversion Instructions ............................................. 5  
GENERAL OPERATION .............................................................. 6  
Lighting and Shutdown Instructions.................................. 6  
Thermostat Adjustment .................................................... 7  
Burner Flame Check .......................................................... 7  
MAINTENANCE ........................................................................ 7  
corrosive vapors and liquids in the vicinity of this or any other  
appliance.  
IMPORTANT  
Before proceeding, please inspect the water heater and components for  
possible damage. DO NOT install any damaged components. If damage is evident  
then please contact the supplier where the water heater was  
purchased or the manufacturer listed on the rating plate for replacement parts.  
TYPICAL INSTALLATION INSTRUCTIONS ..................................... 8  
GENERAL INFORMATION  
This water heater has been manufactured for operation at altitudes from sea  
level to 2000 feet (610m) (unless otherwise specified on the water heater  
rating plate). For use of this appliance at an elevation greater than 2000 feet  
(610m), contact the dealer or manufacturer listed on the rating plate for  
information on any necessary modification. Uncorrected operation of this  
appliance may create a hazard to life and property.  
This gas-fired water heater is design certified by underwriter’s laboratories in  
accordance with the HUD Manufacturer Home Construction and Safety Standard,  
Title 24, part 3280.  
The warranty for this water heater is in effect only when the water heater is  
installed, adjusted, and operated in accordance with these Installation and  
Operating Instructions. The manufacturer will not be liable for any damage  
resulting from alteration and/or failure to comply with these instructions.  
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MFH-I&S-02  
of combustion products resulting in air contamination that may be hazardous to  
life. Such a condition often will result in a yellow, luminous burner flame,  
causing carboning or sooting of the combustion chamber, burners and flue  
tubes with possible damage to the heater.  
Figure 1  
Air Intake Installation - An optional 3" (7.6cm) diameter telescoping air  
intake and leg enclosure are required to supply fresh air to the water heater for  
combustion for 30 gallon (113.5L) water heaters and for 40 gallon (151.4L)  
water heaters. Note: When a mobile home is tightly skirted, an air  
inlet opening in the skirting must be provided. The opening shall  
have a minimum free area of at least 9 in2 (22.9cm2). If the opening  
is screened or covered with a louver, the total free area must be at  
least 9 in2 (22.9cm2). The following steps must be followed for proper  
installation of these air supply components: (Refer to Figure 4.)  
1. After selecting the proper location for the water heater, cut a 4" 10.2cm)  
diameter hole through the floor and all other layers of flooring and  
sheathing directly beneath the center of the water heater.  
Minimum Clearances From  
Combustible Materials  
A
0” (0cm) Left, 2” (5.08cm) Right  
(113.6 Liters only)  
0” (0cm)  
4” (10.16cm)  
78” (1.98m) min  
----  
B
C
D
VENT  
VENTING  
WARNING  
The vent system must be installed properly. Failure to properly  
install the vent system could result in property damage, personal  
injury, or death.  
2. Insert the air intake into the 4" (10.2cm) diameter hole and fasten to  
the floor with the screws provided.  
Make certain the flue baffle is in place and centered in flue tube. Place the  
draft diverter over the flue opening at the top of the water heater by inserting  
the tips of the draft diverter legs into the four (4) holes provided in the water  
heater top. Cut a 7 1/4 inch (18.5cm) diameter hole in the ceiling and roof  
directly above the flue of the water heater. Center the water heater beneath  
the 7 1/4 inch (18.5cm) diameter holes in the roof and ceiling for proper  
alignment of the draft diverter and roof jack vent. Apply non-hardening mastic  
on the roof, around the previously cut hole, to form a weather seal with the  
flashing of the gas vent roof jack assembly. Insert gas vent roof jack assembly  
from above and fasten the flashing to the roof through the pre-punched holes  
in the flashing. Note: Only the roof jacks listed in Figure 4 can be used  
on this water heater. Apply additional non-hardening mastic to complete  
the weather seal. Slip the 3inch (7.62cm) vent connector extension that is  
shipped telescoped, into the gas vent roof jack assembly down onto the draft  
diverter that is secured to the top of the water heater and fasten with the two  
(2) sheet metal screws provided.  
3. Adjust the air intake so the lower tube is extends below the underside  
sheathing and secure with the screws provided. THE BOTTOM OF THE  
AIR INTAKE MUST BE AT LEAST 12" (30.5cm) ABOVE THE  
GROUND LEVEL.  
4. Seal the openings around the air intake and underside sheathing to  
resist the entrance of rodents.  
5. Position the water heater so it is centered above the air intake. (Note:  
The water heater should also be centered with the openings in  
the roof and ceiling to allow for correct assembly of the roof  
jack to the draft diverter.)  
The water heater is to be secured in place using the supplied sheet metal  
strapping and screws. Fasten the base of the water heater to the floor using the  
screws provided. The perforated metal strapping must be fastened to the top  
of the water heater and to the adjacent walls with the screws provided  
(See Figure 4).  
WATER CONNECTIONS  
COMBUSTION AIR SUPPLY  
NOTE:  
WARNING  
BEFORE PROCEEDING WITH THE INSTALLATION, CLOSE THE MAIN WATER SUPPLY VALVE.  
After shutting off the main water supply, open a faucet to relieve the water line  
pressure to prevent any water from leaking out of the pipes while making the  
water connections to the water heater. After the pressure has been relieved,  
close the faucet. The COLD water inlet and HOT water outlet are identified on  
the top of the water heater. The fittings at the cold water inlet and hot water  
outlet are dielectric waterway fittings with 3/4" NPT male thread. Make the  
proper plumbing connections between the water heater and the plumbing  
system to the house. Install a shut-off valve in the cold water supply line.  
Liquefied petroleum gases/propane gas are heavier than air and will remain at floor  
level if there is a leak. Basements, crawl spaces, closets and areas below ground level  
will serve as pockets for accumulation of leaking gas. Before lighting, smell all around  
the appliance area for gas. Be sure to smell next to the floor.  
WHAT TO DO IF YOU SMELL GAS  
Do not try to light any appliance.  
Do not touch any electrical switch; do not use any telephone  
in your building.  
Immediately call your gas supplier from a neighbor’s  
telephone. Follow the gas supplier’s instructions.  
If you cannot reach your gas supplier, call the fire  
department.  
CAUTION  
If sweat fittings are to be use, DO NOT apply heat to the nipples on top of the  
water heater. Sweat the tubing to the adapter before fitting the adapter to  
the water connections. It is imperative that heat is not applied to the nipples  
containing a plastic liner.  
DO NOT OPERATE APPLIANCE UNTIL LEAKAGE IS CORRECTED!  
IMPORTANT  
The flow of combustion and ventilating air must not be obstructed.  
WARNING  
FAILURE TO INSTALL AND MAINTAIN A NEW, LISTED ¾” X ¾”  
TEMPERATUARE AND PRESSURE RELIEF VALVE WILL RELEASE THE  
MANUFACTURER FROM ANY CLAIM WHICH MIGHT RESULT FROM  
EXCESSIVE TEMPERATURE AND PRESSURES.  
All combustion air must be supplied from outdoors by one of the following  
installation methods and as illustrated in (Figure 4). The flow of combustion  
and ventilating air must not be obstructed. Adequate air must be supplied for  
combustion and ventilation. An insufficient supply of air will cause recirculation  
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MFH-I&S-02  
If this water heater is installed in a closed water supply system, such as the one  
having a back-flow preventer in the cold water supply, provisions shall be made  
to control thermal expansion. DO NOT operate this water heater in a closed  
system without provisions for controlling thermal expansion. Your water supplier  
or local plumbing inspector should be contacted on how to control this situation.  
WARNING  
NOTE: Some models may already be equipped or supplied with a  
combination temperature and pressure relief valve. Verify that the  
combination temperature and pressure relief valve complies with local  
codes. If the combination temperature and pressure relief valve does  
not comply with local codes, replace it with one that does. Follow the  
installation instructions above on this page.  
After installation of the water lines, open the main water supply valve and fill  
the water heater. While the water heater is filling, open several hot water  
faucets to allow air to escape from the water system. When a steady stream  
of water flows through the faucets, close them and check all water connections  
for possible leaks. NEVER OPERATE THE WATER HEATER WITHOUT FIRST  
BEING CERTAIN IT IS FILLED WITH WATER.  
Install a discharge line so that water discharged from the combination  
temperature and pressure relief valve will exit within six (6) inches  
(15.2 cm) above, or any distance below the structural floor and cannot  
contact any live electrical part. The discharge line is to be installed to  
allow for complete drainage of both the combination temperature and  
pressure relief valve and the discharge line. The discharge opening  
must not be subjected to blockage or freezing. DO NOT thread, plug  
or cap the discharge line. It is recommended that a minimum clearance  
of four (4) inches (10.2 cm) be provided on the side of the water  
heater for servicing and maintenance of the combination temperature  
and pressure relief valve.  
WARNING  
Hydrogen gas can be produced in an operating water heater that  
has not had water drawn from the tank for a long period of time  
(generally two weeks or more). Hydrogen gas is extremely flammable.  
To prevent the possibility of injury under these conditions, we  
recommend the hot water faucet to be open for several minutes at the  
kitchen sink before you use any electrical appliance which is connected  
to the hot water system. If hydrogen is present, there will be an  
unsual sound such as air escaping through the pipes as hot water  
begins to flow. Do not smoke or have open flame near the faucet at  
Do not place a valve between the combination temperature and pressure  
relief valve and the tank.  
the time it is open.  
This water heater can deliver scalding temperature water at any faucet in the  
system. Be careful whenever using hot water to avoid scalding injury. Certain  
appliances such as dishwashers and automatic clothes washers may require  
increased temperature water. By setting the thermostat on this water heater to  
obtain the increased temperature water required by these appliances, you may  
create the potential for scald injury. To protect against injury, you should install  
an anti-scald tempering valve in the water system. This valve will reduce point  
of discharge temperature by mixing cold and hot water in branch supply lines.  
Such valves are available from the local plumbing supplier. Please consult with  
a plumbing professional.  
WARNING  
For protection against excessive temperatures and pressure, install  
temperature and pressure protective equipment required by local codes,  
but not less than a combination temperature and pressure relief valve  
certified by a nationally recognized testing laboratory that maintains  
periodic inspection of production of listed equipment or materials as  
meeting the requirements of the Standard for Relief Valves and Automatic  
Gas Shutoff Devices for Hot Water Supply Systems, ANSI Z21.22 or the  
Standard CAN1-4.4. Temperature and Pressure and the Standard CAN1-  
4.4, Temperature, Pressure, Temperature and Pressure Relief Valves  
and Vacuum Relief Valves. The combination temperature and pressure  
relief valve shall be marked with a maximum set pressure not to  
exceed the maximum working pressure of the water heater. The  
combination temperature and pressure relief valve shall also have an  
hourly rated temperature steam BTU discharge capacity not less than  
the hourly rating of the water heater.  
GAS CONNECTIONS  
The gas supply lines must meet all requirements of the National Fuel Gas Code  
ANSI Z223.1-(Latest Edition) and/or in Canada CAN/CGA B149 Installation  
Codes - (Latest Editions).  
The minimum permissible gas supply pressure for the purpose of input  
adjustment is 1.0" water column (.25kPa) above the operating manifold pressure.  
See the rating plate and combination gas control for the manifold pressure and  
gas type. The maximum permissible gas supply pressure is 14.0" water column  
(3.5kPa) for natural gas and liquefied petroleum gases/propane gas.  
Install the combination temperature and pressure relief valve into the  
opening provided and marked for this purpose on the water heater.  
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MFH-I&S-02  
1. Connect this water heater only to the type of gas (Natural or Propane gas)  
as shown on the rating plate. Use clean 1/2"black iron pipe. (Dirt and scale  
from the pipe can enter the combination control and cause it to malfunction).  
The inlet gas line must have a minimum length of 3" (7.6 cm) drip leg  
(sediment trap) installed as close to the water heater’s combination gas  
control as possible. A ground joint union must be installed in the gas supply  
line feeding the water heater to permit servicing of the water heater.  
Compounds used on the threaded joints of the gas piping must be resistant  
to the action of liquefied petroleum gases/propane gas.  
2. This water heater and its gas connection must be leak tested before placing  
the water heater in operation. Check for gas leaks with a soap and water  
solution and a brush or a commercial leak detector fluid. NEVER USE A  
MATCH OR OPEN FLAME FOR TESTING!  
3. Change the pilot regulator by removing thermostat dial and pilot regulator  
cap. Depress and rotate knob clockwise  
screwdriver. Replace cap.  
to the L.P. setting using a  
4. Remove the outer door. Remove, or slide open, the inner door.  
5. Disconnect thermocouple, Gas supply tube and pilot tube from the gas  
valve and remove the burner assembly from the water heater.  
6. Remove main burner orifice and pilot assembly and replace with “RED”  
color coded L.P. orifice and pilot assembly provided in the cloth bag  
attached to the water heater.  
CAUTION  
The water heater and individual shut-off valve must be disconnected from the  
gas supply piping system during any pressure testing of the system at test pressures  
in excess of ½ psi (3.5kPa). The water heater must be isolated from the gas supply  
piping system by closing its manual shut-off valve during any pressure testing of  
the gas supply system at test pressures equal to or less than ½ psi (3.5kPa). The  
supply line must be capped when not connected to the water heater.  
This water heater has a gas control which will operate on either natural or  
liquefied petroleum (LP) gas. Normally the control is set to operate on natural  
gas, but can be converted for liquefied petroleum (LP) gas by following these  
instructions for gas conversion.  
CAUTION  
All gas conversions must be performed by qualified service personnel only.  
7. Replace the burner assembly and reconnect all fittings.  
8. Close and/or replace inner and outer doors.  
9. To light pilot, follow the lighting instructions provided on the water heater  
and in this installation and operation instruction manual.  
GAS CONVERSION INSTRUCTIONS  
To convert from natural gas to LP gas  
1. Depress and rotate gas main burner regulator knob clockwise  
the “OFF” position.  
2. Change main burner gas regulator by removing cap from gas regulator.  
to To convert from LP to natural gas  
1. Follow the instructions above except remove the “RED” main burner orifice  
and pilot assembly. Replace with the ones originally provided with the  
Depress and rotate knob counterclockwise  
using a screwdriver. Replace cap.  
to the L.P. setting  
water heater.  
2. Change the main gas regulator to “NAT” as noted in step 2 of the above  
instructions.  
3. Change the pilot regulator to “NAT” as noted in step 3 of the above  
instructions.  
GENERAL OPERATION  
WARNING  
Water heaters are heat producing appliances. To avoid damage or injury there  
shall be no materials stored against the water heater or vent-air intake system,  
and proper care shall be taken to avoid unnecessary contact (especially by  
children) with the water heater and vent-air intake system. UNDER NO  
CIRCUMSTANCES SHALL FLAMMABLE MATERIALS, SUCH AS GASOLINE  
OR PAINT THINNER BE USED OR STORED IN THE VICINITY OF THIS  
WATER HEATER, VENT-AIR INTAKE SYSTEM OR IN ANY LOCATION  
FROM WHICH FUMES COULD REACH THE WATER HEATER OR  
VENT-AIR INTAKE SYSTEM.  
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MFH-I&S-02  
TO FILL THE WATER HEATER  
1. Close the water heater drain valve by turning the knob clockwise.  
2. Open the cold water supply shut-off valve.  
3. Open several hot water faucets to allow air to escape from the system.  
4. When a steady stream of water flows from the faucets, the water  
heater is filled. Close the faucets and check for water leaks at the water  
heater drain valve, combination temperature and pressure relief valve  
and the hot and cold water connection.  
5. Wait five (5) minutes to clear out any gas. Then smell for gas, including near the  
floor. If you smell gas, STOP! Follow “B”: in the safety information above on this  
table. If you don’t smell gas, go to the next step.  
6. Remove outer door. Remove inner door or slide it open.  
7. Find pilot. Follow aluminum tube from the “right underside” of the gas control.  
The pilot is adjacent to the burner.  
TO DRAIN THE WATER HEATER  
Should it become necessary to completely drain the water heater, make  
sure you follow the steps below:  
1. Rotate the thermostat dial clockwise to the “PILOT LIGHTING” position.  
2. Rotate and partially depress gas control knob clockwise to the “OFF”  
position.  
8. Turn the gas control knob to the “PILOT” position.  
9 a. FOR EXHIBIT A GAS CONTROLS -  
3. Shut off the gas supply to the water heater.  
4. Close the cold water supply shut-off valve.  
5. Open the drain valve on the water heater by turning the knob  
counter-clockwise. The drain valve has threads on the end that will  
allow the connection of a standard hose coupling.  
6. Open a hot water faucet to allow air to enter the system.  
Depress and hold down red pilot set button. Immediately light the pilot with a  
match. Continue to hold down the red button for about one (1) minute after the  
pilot is lit. Release button and it should pop back up. Pilot should remain lit. If it  
goes out, repeat steps 5 through 9.  
9b. FOR EXHBIT B GAS CONTROLS -  
Depress and hold down gas control knob. Immediately light the pilot with a  
match. Continue to hold down the knob for about (1) minute after the pilot is  
lit. Release the knob and it should pop back up. Pilot should remain lit. If it goes  
out, repeat steps 5 through 9.  
To refill the water heater, refer to “To Fill the Water Heater.”  
FOR YOUR SAFETY READ BEFORE LIGHTING  
FOR EXHBIT A & B GAS CONTROLS -  
* If button or knob does not pop up where released, stop and immediately call  
your technician or gas supplier.  
* If the pilot will not stay lit after several tries, turn the gas control knob to  
“OFF” and call your technician or gas supplier.  
WARNING  
If you do not follow these instructions exactly, a fire or explosion may result  
causing property damage, personal injury or loss of life.  
10. Replace inner door or slide it closed. Replace outer door.  
11. Turn gas control knob counterclockwise to on position.  
12. Set thermostat to desired setting.  
A. This appliance has a pilot which must be lighted by hand. When lighting the  
pilot, follow these instructions exactly.  
13. If applicable, turn on all electric power to the appliance.  
B. BEFORE LIGHTING smell all around the appliance area for gas. Be sure to  
smell next to the floor because some gas is heavier than air and will settle on the  
floor.  
TO TURN OFF GAS TO APPLIANCE  
1. Turn off all electric power to the appliance if service is to be performed.  
2. Set the thermostat to the lowest setting.  
3. Rotate and if applicable, partially depress gas control knob clockwise to “OFF”  
position.  
WHAT TO DO IF YOU SMELL GAS  
• Do not try to light any appliance.  
• Do not touch any electric switch; do not use any telephone in your  
building.  
WARNING: FOR YOUR SAFETY  
• Immediately call your gas supplier from a neighbor’s telephone. Do not store or use other flammable, combustible, or corrosive vapors or liquids in the  
Follow the gas supplier’s instructions.  
vicinity of this or any other appliance.  
• If you cannot reach your gas supplier, call the fire department.  
WARNING: HOT WATER CAN PRODUCE 3RD DEGREE BURNS  
C.. Use only your hand to push in or turn the gas control knob. Never use tools. If In 6 seconds at 140°F (60°C) - In 30 seconds at 130°F (24°C)  
the knob will not push in or turn by hand, don’t try to repair it, call a qualified  
service technician. Force or attempted repair may result in a fire or explosion.  
Vapors from flammable liquids will explode and catch fire causing death or severe  
D. Do not use this appliance if any part has been under water, immediately call a burns.  
qualified service technician to inspect the appliance and to replace any part of Read and follow water heater warnings and instructions. If installation and operation  
the control system and any gas control which has been under water.  
instructions are missing, contact the retailer or manufacturer.  
LIGHTING INSTRUCTIONS  
1. Stop! Read the safety information above on this label.  
2. If applicable, turn off all electric power to appliance.  
This appliance must be installed in accordance with local codes or, in the absence of local  
codes, the National Fuel Gas Code, ANSI 7223.1. Or the CAN/CGA-B149 installation  
codes. For installation in a manufactured home (mobile home).  
3. Rotate the thermostat dial counter-clockwise to the lowest possible position.  
4. Rotate gas control knob clockwise to the “OFF” position.  
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MFH-I&S-02  
BURNER FLAME CHECK  
CAUTION: Operation of this water heater in air contaminated by  
perchloroethylene, any chlorinated hydrocarbon or strong oxidizing agents, will result  
Steel Burner: These models are equipped with self adjusting air mixture and  
do not have an adjustable air shutter (See Figure 3). At periodic intervals, a  
visual check of the main burner and pilot flames should be made to determine  
if they are burning properly. The main burner flame should light smoothly from  
the pilot.  
in serious damage to brass orifices, internal steel parts and void the warranty.  
IMPORTANT – BURNER MUST BE LEVEL. Models containing a cast iron burner  
are equipped with an adjustable air shutter. The air shutter on the front of the main  
burner must be adjusted when the water heater is installed. See installation instructions  
for proper air shutter adjustment procedures.  
STATE OF CALIFORNIA NOTICE  
WARNING: This water heater must be braced, anchored or strapped to  
avoid falling or moving during an earthquake. See instructions for correct installation  
procedures.  
WARNING: If not installed, operated and maintained in accordance with  
the manufacturer’s instructions this product could expose you to substances in the fuel  
or form combustion which can cause death or serious illness including, cancer, birth  
defects or other reproductive harm.  
Figure 3  
MAINTENANCE  
SUITABLE FOR WATER (PORTABLE) HEATING AND SPACE HEATING  
Toxic chemicals, such as used for boiler treatment, shall not be introduced into potable  
water heater used for space heating. This water heater may never be connected to any  
existing heating system or component(s) previously used with a nonpotable water  
heater appliance.  
WARNING  
Water heaters are heat producing appliances. To avoid damage or injury there  
shall be no materials stored against the water heater or vent-air intake system  
and proper care shall be taken to avoid unnecessary contact (especially by  
children) with the water heater and vent-air intake system. UNDER NO  
CIRCUMSTANCES SHALL FLAMMABLE MATERIALS, SUCH AS  
GASOLINE OR PAINT THINNER BE USED OR STORED IN THE  
VICINITY OF THIS WATER HEATER, VENT-AIR INTAKE SYSTEM OR IN  
ANY LOCATION FROM WHICH FUMES COULD REACH THE WATER  
HEATER OR VENT-AIR INTAKE SYSTEM.  
THERMOSTAT ADJUSTMENT  
The thermostat dial is adjusted to its lowest temperature position when shipped  
from the factory. When adjusting the thermostat it should be remembered  
that lower temperature settings are more energy efficient. To adjust the  
thermostat, turn the dial clockwise until the minimum acceptable temperature  
is set. It is suggested that the starting point setting not exceed the “HOT” mark  
[approximately 120°F (49° C)] on the thermostat, as indicated in Figure 2.  
IMPORTANT  
The water heater should be inspected at a minimum annually by a  
qualified service technician for damaged components and/or joints  
not sealed. DO NOT operate this water heater if any part is found  
damaged or if any joint is found not sealed.  
Figure 2  
The following maintenance should be performed by a qualified service technician  
at the minimum periodic intervals suggested below. In some installations, the  
maintenance interval may be more frequent depending on the amount of use  
and the operating conditions of the water heater. Regular inspection and  
maintenance of the water heater and vent-air intake system will help to ensure  
safe and reliable operation.  
1. Annually check the operation of the thermostat.  
2. The flow of combustion and ventilation air MUST NOT be restricted. Clear  
DANGER  
Hotter water increases the risk of scald injury. Scalding may occur within  
the combustion air openings of any dirt, dust, or other resctrictions.  
five (5) seconds at a temperature setting of 135°F (57°C). To protect  
against hot water injury, install an anti-scald tempering valve in the water  
system. This valve will reduce point of discharge temperature by mixing  
cold and hot water in branch water lines. A licensed plumbing professional  
or local plumbing authority should be consulted.  
Note: This water heater is equipped with an energy cut out device to  
prevent overheating. Should overheating occur or the gas supply fail to  
shut off, turn off the manual gas control valve to the appliance and call  
qualified service technician.  
Note: Whenever the water heater is filled with cold water, condensate will form on  
the cool tank surface and drops of water will fall on the hot burner and combustion  
chamber surfaces producing a “sizzling” noise. Condensation is normal and does  
not indicate a leak. It will disappear when the tank becomes heated.  
WARNING! The ventilation air system may be HOT.  
3. At all times keep the water heater area clear and free from combustible  
materials, gasoline and other flammable vapors and liquids.  
4. Bi-annually conduct a visual check of the main and pilot burner flames to  
determine that they are burning properly. See Burner Flame Check section  
on page 7.  
5. Annually remove the inner door and main burner assembly to clean orifices  
and related parts of any dirt or other foreign material. Inspect the burner  
ports for obstructions or debris and clean with a wire brush as needed. Wire  
brush and/or vacuum clean the combustion chamber as needed to remove  
scale deposits and debris. Note: It is imperative for proper operation of  
the water heater that the inner door be replaced in the original location.  
7
 
MFH-I&S-02  
9. A combination sacrificial anode rod/hot water outlet nipple has been  
installed to extend tank life. The anode rod should be inspected periodically  
(every 2 years) and replaced when necessary to prolong tank life. Water  
conditions in your area will influence the time interval for inspection and  
replacement of the anode rod. Contact the plumbing professional who  
installed the water heater or the manufacturer listed on the rating plate for  
anode replacement information. The use of a water softener may increase  
the speed of anode consumption. More frequent inspection of the anode  
is needed when using softened (or phosphate treated) water.  
WARNING  
When lifting lever of the combination temperature and pressure  
relief valve, hot water will be released under pressure. Be  
careful that any released water does not result in bodily injury  
or property damage.  
6. At least once a year, check the combination temperature and pressure  
relief valve to insure that the valve has not become encrusted with lime.  
Lift the lever at the lever at the top of the valve several times until the  
valve seats properly without leaking and operates freely.  
CAUTION  
7. Monthly drain off a gallon of water to remove silt and sediment.  
FOR YOUR SAFETY, DO NOT ATTEMPT REPAIR OF COMBINATION GAS CONTROL,  
WARNING! THIS WATER MAY BE HOT.  
BURNERS OR GAS PIPING. REFER REPAIRS TO A QUALIFIED SERVICE TECHNICIAN.  
8. If the combination temperature and pressure relief valve on the appliance  
discharges periodically, this may be due to thermal expansion in a closed  
water supply system. Contact the water supplier or local plumbing inspector  
on how to correct this situation. Do not plug the combination temperature  
and pressure relief valve outlet.  
Contact your supplier or plumbing professional for replacement parts or contact  
the company at the address given on the rating plate of the water heater.  
Provide the part name, model and serial numbers of the water heater when  
ordering parts.  
TYPICAL INSTALLATION - VENTING  
Figure 4  
4-08/Printed in USA  
8
 

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