Girard Products GSWH-1 User manual

Service Manual
Girard Products LLC, 1361 Calle Avanazado, San Clemente CA 92673 U.S.A
Service Manual Part No. 1GWHM9405 - 10/1/2014
LP Gas
Tankless
Water Heater
This manual is intended solely for use by trained personnel
who perform service or repairs on the Model GSWH-1 and
GSWH-1M Water Heater on behalf of a Girard Products LLC
Authorized Service Center.
Model: GSWH-1
Model: GSWH-1M
For Recreation
Model: GSWH-1 Patent Pending
Model: GSWH-1M Patent Pending
CSA Approved
For Recreation Vehicles

TABLE OF CONTENTS
Service Manual
Model GSWH-1 & Model GSWH-1M
Title Page
1. Introduction .......................................................................................................... 3
2. Product Identification GSWH-1 ............................................................................... 4
3. Product Identification GSWH-1M............................................................................. 5
4. Description and Features........................................................................................ 6
5. Normal Operation GSWH-1..................................................................................... 7
6. Normal Operation GSWH-1M .............................................................................. 8-9
7. Recommended Tools and Equipment ..................................................................... 10
8. Removing Controls Housing .................................................................................. 11
9. Schematics and Diagrams
a. Ladder Diagram GSWH-1 & GSWH-1M ..........................................................12
b. Wiring Diagrams ...........................................................................................13
10. Circuit Board Operation ........................................................................................ 14
11. Troubleshooting Guide/ Exploded Views ............................................................15-16
12. Component Information....................................................................................17-21
13. Gas Modulation Explanation and Testing ...........................................................22-25
14. Circuit Board Troubleshooting ................................................................................26
15. General Failures and Possible Causes and Remedies.........................................27-28
16. Routine Maintenance ............................................................................................29
17. Winterization ........................................................................................................30
18. Parts Breakdown ..................................................................................................31
19. Flat Rate Schedule ...............................................................................................32
20. Service Procedures...............................................................................................33
22. Addendum (Technical Bulletins/Parts List/General Information)...........................34-42
2Page

INTRODUCTION (Must Read!)
The original Girard Water Heater was Model Number 1GWH/1GWHAF.
AF indicates (Winter Use Device).
The front portion of this manual will concentrate on the models listed above.
In August 2012 Girard redesigned and replaced the original product and assigned the
Model Number GSWH-1M, referred to as the M-Series. The (Winter Use Device) is
integrated into all of these water heaters, so there is only one model number instead of
two, as before.
The basic operation of both water heaters is the same. Most diagnostic and
troubleshooting will be similar. The primary difference will be seen in the way the
burners are adjusted from Low to High and the variation of the BTU ratings between the
two. Since different methods are used to adjust the BTUs, (the 1-Series uses a switch
and the M-Series uses a dial), the components that make this possible are different.
During our frequent seminars within the US and Canada, we compare the Girard Water
Heater to an RV furnace, since most technicians are familiar with the furnaces. If
you are familiar with the operation and diagnosis of an RV furnace, you will also be
familiar with a Girard water heater. While a furnace heats air, we are heating water. As
with a furnace, the water heater installation requires certain parameters for its proper
operation. These will be discussed later in the manual.
The primary components in the Girard Water Heater are:
1. 12 volt motor with blower wheel
2. DSI motor control board
3. Electrode
4. Burners
5. Safety switches, ECO, high limit
6. Sail switch
7. Standard 12 volt gas solenoid valve
8. Pressure relief valve
9. Relay
There are a few other components that will be discussed in this manual, but as you can
see, most are identical or similar to those found in the furnace.
If you are not familiar with the Girard Tankless Water Heater, please read this manual in
advance of attempting any repairs.
3Page

BTU/HR 27,000 – 34,000
Fuel Propane (LP Gas)
Inlet Pressure 10.5” WCI Min to 14” WCI Max
Manifold Pressure 8” – 10” WCI
Power Input 12VDC < 3 amp
Water Operating Pressure 125 PSI Max
Max Water Temperature 122 º F
Dimension Width: 12.5” - Height: 12.5” - Depth 15.5”
Shipping Weight 22 lbs
Specifications
The main performance specifications of the Model GSWH-1 are:
PRODUCT IDENTIFICATION - GSWH-1
Water Heater Part Number: 1GWH / 1GWHAF (w/ Winter Use Device)
Door Part Number: 1GWHD, 1GWHDA6, 1GWHDAS10
Serial Number Location: Rating Label affixed on the inside right of
the Controls Housing.
Figure 1
4Page

BTU/HR 18,000 – 36,000
Fuel Propane (LP Gas)
Inlet Pressure 10.5” WCI Min to 14” WCI Max
Manifold Pressure 8” – 10” WCI
Power Input 12VDC < 3 amp
Water Operating Pressure 125 PSI Max
Max Water Temperature 131 º F
Dimension Width: 12.5” - Height: 12.5” - Depth 15.5”
Shipping Weight 22 lbs
Specifications
The main performance specifications of the Model GSWH-1M are:
PRODUCT IDENTIFICATION - GSWH-1M
Water Heater Part Number: 1GWH-1M
Door Part Number: 1GWHD, 1GWHDA6, 1GWHDAS10
Serial Number Location: Rating Label affixed to Blower Assembly
Housing
Figure 1a
5Page

6Page
DESCRIPTION AND FEATURES
The Girard Products GSWH-1 LP and the GSWH-1M LP Gas Tankless Water Heater are designed
to meet ANSI Z21.10.3-2004 and CSA 4.3-2004 and are certified by the Canadian Standards
Association (CSA) to meet these standards for use in recreation vehicles.
The design of this product differs from the traditional storage tank water heater units found in
RVs. More specifically:
 •TheGirardTanklessHotWaterSystemusesannedcopperheatexchangerandninehigh
efficiency blade burners.
 •TheMotorAidedInducedDraftenhancescombustionforincreasedefciencyandimproved
wind resistance.
 •The1-SeriesdualBTUGasValve/wHigh/LowSwitchoptimizestheoutputtemperature
range based on the temperature of the input cold water and water flow. BTU rating: 27,000
Low, 34,000 High
 •The1M-SeriesutilizesaDIALtocontrolaModulatingValvethatprovidesfortotalvariation
of BTUs from 18,000 to 36,000.
When properly installed in a Recreation Vehicle the Girard Tankless Water Heater is connected to:
 •TheRV’scoldwatersystemwithitswaterinputfromapressurized(45psi)sourcesuchas
a shore connection or a water storage tank with water pump.
 •TheRV’shotwatersystem(i.e.faucetsandshower)
 •TheRV’sLPGassystemcapableofsupplyingtheratedBTUrequirement.
 •TheRV’s12VDCElectricalpowerdistributionpanelona10ampfusedcircuit
Please refer to the Owners Manual supplied with the unit for further information. The Owners
Manual will allow you to verify if the unit is properly installed and the connections are within the
following recommended parameters:
 •Thepressureofthewatersupplyisbetween40and60psifornormaloperation
 •TheLPGassystemisoperatingwithintheinletpressurelimitsindicatedontheratinglabel
(10.5” and 14” WC)
 •TheDCVoltageappliedisgreaterthan11.5andlessthat14VDC
 •Asteadywaterow
Figure 2

7Page
NORMAL OPERATION - GSWH-1
A tankless water heater, also referred to as an “on demand” water heater, rapidly heats water as
it flows around and through the heat exchanger. The output water temperature depends on the
temperature of the input water and the flow established at the faucet by the user; the faster the
flow, the cooler the water; the slower the flow, the hotter the water.
The gas control valve of the GSWH-1 and the GSWHAF-1 features a dual BTU solenoid that can
operate in HIGH mode (34,000 BTUs) or LOW mode (27,000 BTUs). The BTUs will normally be
set to HIGH or LOW depending on the incoming water temperature or normally LOW for summer
and HIGH during cooler temperatures.
Prior to normal operation the user must ensure that all air has been purged from the water lines,
the Water Heater Power Switch is in the ON position and the REMOTE Mode Switch is set in the
desired position (LOW or HIGH). The 12VDC power is normally left ON while the RV is in use with
no use of LP gas. In most cases the ON/OFF switch can be left ON the entire camping season.
This will not harm the unit in any way.
To start the water heater the user should fully open the HOT water faucet, wait for hot water
to flow. IF hotter water is desired, you can slightly reduce the water flow. This will increase the
temperature to the desired level.
Note: As with all water heaters (even though Girard Water Heaters heat water instantly),
there will still be a lag time between time of ignition and warm water coming out of the faucet.
Thus, the further the water heater is located from the faucet/shower, the longer it will take the
user to feel the hot water.
During normal operation the hot water faucet behaves somewhat like a typical mixing valve: it
(faucet) increases the water temperature when the flow is decreased and decreases the tem-
perature when the flow is increased.
The user may need to mix a small amount of cold water with the hot when the incoming water
temperature is very hot (80° F - 90° F). This is not uncommon in the Southern states during the
summer months. Remember that the increased total flow of the hot and cold water will reduce
the flow of water through the heat exchanger. This can cause the hot water output temperature
to increase, defeating the effect of the cold water. In some cases adding cold water may result in
“LIMITING”. (See Below)
If the output temperature exceeds 123 º F an Emergency Cut-Off (ECO) thermostat will shut
down the flame in the water heater to prevent scalding. During this time the blower will continue
to operate. When the temperature returns to a safe level, the flame will come back on. This is
referred to as “LIMITING”
I

NORMAL OPERATION - GSWH-1M
The Girard Tankless Water Heater (M-Series), also referred to as an “on demand” water heater,
rapidly heats water as it flows around and through the heat exchanger. The output water
temperature depends on the temperature of the incoming water and the flow established at the
faucet and the dial setting.
Water flow is critical since the SLOWER the water flows (through the heat exchanger), the
HOTTER the water temperature and the FASTER the water flow, the COOLER the water
temperature.
The BTU adjustment for the M-Series water heater operates through a modulator rather than
the gas valve. The modulator control increases the amount of gas flow to the burners as the dial
is turned from LOW to HIGH. On the LOW setting, the water heater operates at approximately
18,000 BTUs. On the high setting, approximately 36,000 BTUs. The LOW setting will increase
the water temperature by approximately 20° F from the input water temperature. Placing the
dial on the HIGH setting will increase the water temperature by approximately 70° F depending
on the input water temperature. A thermostat setting may vary +/-5° F - The ECO setting 131°.
Later models with dual ECO/High Limit 131°/167° resetable.
Prior to Operation
The end user/technician must insure that all air has been purged from all on-board water lines.
To purge the system (purging procedure needs to be done at the beginning of the camping
season or if any water line is evacuated / drained of water)
1. Verify the switch is in the (Off) position.
2. Turn on the water supply to the unit.
3. Open and then close all the HOT and COLD water faucets at the kitchen, bathroom,
inside shower, toilet, outside shower, washer (if equipped) and any other inside or outside
faucets.
4. Close the faucets when the water is flowing smoothly.
5. Check for any noticeable water leaks.
6. Confirm the LP gas is turned on.
7. Turn the power switch to the ON position. This switch can be left ON during the entire
camping season. This will not harm the unit in any way.
8. Open a hot water faucet to verify that the unit ignites and supplies warm water.
Operating the Water Heater
To start the water heater the user/technician should fully open the hot water faucet and
wait for the water to become warm. The water will become warm as soon as the water from
the water heater reaches the faucet. Thus, the distance of the water heater from the faucet
determines how long it will take for the water to become warm. When a change is made in water
temperature or flow, the distance will also effect this time. As a technician, you will notice that
even when the water heater is close to the faucets, sometimes the routing of the water lines
might not be a direct line.
8Page

Controlling the Hot Water Temperature
1. The dial makes adjustment to the water temperature very easily. Generally a dial
adjustment is all that is required. Turn the dial clockwise to increase the temperature and
counter-clockwise to reduce the temperature.
2. If additional adjustment is required, increase or decrease the flow of hot water. Increase the
flow to to reduce the temperature slow the flow to increase the temperature.
3. If the water is too hot after making the adjustments mentioned above, you may add a small
amount of cold water to reduce the temperature.
One of the most common complaints is that the water temperature cycles between hot and cold.
The ECO safety switch is designed to OPEN at 131°. When this occurs, the burners will shut
off for a short time until the ECO closes or resets itself, turning the burners back on. There are
several reasons when this may occur:
1. The dial is set too high for the incoming water temperature. Turn dial down.
2. Water lines have not been purged, or completely purged. Purge entire RV again, following
the information discussed above.
3. Incoming water flow very low. The water heater should have at least 1 GPM for proper
operation. Test GPM by setting a 1 gallon container at one of the hot water faucets. If the
container fills in 1 minute, there is at least 1 GPM. If it does not fill, there is less than 1
GPM. If the problem of water flow cannot be resolved, place water in the fresh water tank
and operate and operate off of the pump.
If the customer has attached a flow restrictor, remove water restrictor from incoming water hose.
Ifawaterlterisinuse,besurethattheltermediaisnotreducingowbecauseit’stodirty.
Girard does not require a By-Pass during the installation. If this is a replacement water heater, or
if the OEM installs a By-Pass, be sure the By-Pass is set for summer usage. We recommend that
the By-Pass stay in this position all year.
9Page

10Page
RECOMMENDED TOOLS AND EQUIPMENT
No unusual tools and/or equipment are needed to service the Girard Tankless Water Heater.
The following equipment is commonly used for service and is readily available. Be sure that all
instruments are regularly calibrated.
U-Tube or Dial Type
Manometer
This device is for
measuring the gas
pressure. If using a
dial type manometer
please insure that it is
regularly calibrated.
Gas Leak Test Solution
There are many inexpensive solutions on the market that
bubble when applied to fittings where a leak is present.
Multimeter
Used for testing Continuity, Voltage, Current (AC/DC) and
Resistance. With a good quality Multimeter you can verify voltage
problems and defective components. The entire electronic system
can be tested with this meter.
Fenwal Board Tester or Similar Approved Tester
Used for testing the Circuit Board. This tester will diagnose
the power circuit, sense circuit, spark igniter and lock-out
mode. Fenwal part # 05-080224-009)
U-Tube Manometer Dial Type Manometer
ON VALVE CHECK
OFF
CURCUIT BOARD TESTER
IGNITER
OFF
REMOTE
FLAME
Hand Tools:
 •Phillipsandatheadscrewdrivers
 •9/16”,3/4”and13/16”S.A.E.openwrenches
 •7mmand5.5mmnutdriversand/orwrenches.
 •Needlenosepliers,wirecrimpandcutter.
 •LeakTestSolution.

11Page
REMOVING CONTROL HOUSING
No unusual tools and/or equipment are needed to service the Girard Tankless Water Heater.
The following equipment is commonly used for service and is readily available. Be sure that all
instruments are regularly calibrated.
To gain easy access to the serviceable components of the Water Heater you must first remove
theControls’Housingthatshieldsandsupportsthefollowing:
 •CircuitBoard
 •DualBTUGasControl
 •MainGasLine
 •Groundconnections
 •PowerswitchwiththeLEDindicator
Figure 3
GSWH-1M
Access to Board and Gas Valve
•BOARD-Locatethescrewattheupperleftofthecontrolpanel.Removescrewandlift
BOARD out of bracket.
•VALVEACCESS-Locateplateatlowerrightsideofcontrolpanel.Remove2screws
holding plate. Remove plate to provide access to GAS VALVE for testing.

12Page
SCHEMATICS AND DIAGRAMS
Figure 5
Ladder Diagram GSWH-1M
Figure 4
Ladder Diagram GSWH-1

13Page
Please refer to the electrical diagram for a functional understanding of the electrical components
and of the Circuit Board control functions.
Figure 6
Wiring Diagrams
Figure 7
Wiring Diagram
GSWH-1M
Wiring Diagram
GSWH-1

14Page
CIRCUIT BOARD OPERATION
When the user opens a Hot Water faucet, water starts flowing through the unit and activates the
Flow Switch which in turn activates the Relay; this applies 12VDC power to the ECO (Emergency
Cut-Off Thermostat) and to the “Heat Demand” Connection (5) of the Circuit Board (see below).
Changeto:….ECO(EmergencyCut-OffThermostat)andtothe‘TH’Connection(2)oftheCircuit
Board.
Power is then applied to the Sail Switch that is open when there is no air flow from the blower.
The ECO is normally closed. The Circuit Board starts the blower and verifies that the Sail Switch
closes: when this occurs the Circuit Board will sense the 12VDC at the Circuit Board indicating
that there is sufficient air flow for combustion. The circuit is now complete.
Try For Ignition (TFI)
The Circuit Board is now ready to try for ignition and applies power to the gas valve through
connection (4) and without delay generates a spark of five (5) seconds duration at the igniter. If
the Circuit Board does not sense flame at the spark igniter, the gas valve is de-energized and
an internal post purge of 15 seconds will occur before a second try is attempted. Two additional
tries will be attempted and if no flame is detected in the process the Circuit Board goes into
LOCKOUT mode and will make no further attempt to light. Once the system has entered lockout
mode, it must be reset. To reset the water heater, turn OFF power to the water heater OR close
the faucet (removing the demand for hot water for a period of five (5) seconds.
Figure 6

15Page
Exhaust Collector Limit Switch
Heat Exchanger
Relay
Gas Control Valve
Wire
Connections
Hot Water
Flow
Switch
Cold Water
Auto-Lo Thermostat
Gas Burner
Burner Manifold
Anti-Freeze Thermostat
Power Switch
Diagnostic LED
Circuit Board (Fenwal)
Sail Switch Housing
Exhaust Tube
Door Flange Door
EXPLODED VIEW OF MODEL GSWH-1 AND MAJOR COMPONENTS IDENTIFICATION
Blower Motor Assembly Support
Control Panel Housing
Figure 7
TROUBLE SHOOTING GUIDE
This section includes the most common symptoms that may be found in a model GSWH-1 that is
not operating normally. Please refer to the following drawing to locate the components in the unit:
NOTICE: Before starting the troubleshooting steps suggested below verify that:
•Thereispowerconnectedtothewaterheater
•ThepowerswitchisintheONposition
•Thewiringisnotdamagedinanyway
•Allconnectorsarepluggedin(nodanglingconnectors)
•Waterowingthroughtheunitwhenyouopenahotwaterfaucet
•TheSailSwitchismovingfreely(forwardandbackward)
•Thegasisconnectedandthegastankisnotempty
Figure 8

16Page
Whenever the Circuit Board senses flame during the ignition trials, sparking stops and the Gas
Valve remains energized. The Water Flow Switch, the Sail Switch and the Burner flame are
constantly monitored to assure that the system continues to operate properly.
When the Hot Water faucet is closed and the Flow Switch opens, the demand for heat ends and
the Gas Valve is de-energized immediately; after the post purge and cool off period of 90 +/-
seconds the blower is turned off.
Flame Failure
If the established flame signal is lost while the burner is operating, the control will sense this
and respond within 0.8 seconds. The gas valve will stay energized and the Ignition Spark will
be energized in an attempt to relight the burner (trial for ignition). If the burner does not light,
the control will make two more attempts to relight and then go into lockout (See Try for Ignition-
page 10). If flame is established.
Combustion Airflow Problems
If the airflow signal is lost, or the ECO opens during heat mode, the gas valve is immediately
de-energized and the blower stays on. If the switch closes again, a normal ignition sequence
will resume. If not and this condition persists for more than five minutes, the control will enter
lockout (See Try for Ignition - page 10) with the blower off.
Water Heater LED Diagnostics
If the water heater stops operating normally, check the LED indicator on the user panel located
behind the water heater door. If the LED is lit or blinking, consult the list below to help diagnose
the fault detected by the Circuit Board:
• Steady On – Internal Control Fault
• 1 Flash – Air Fault
• 2 Flashes – Flame Detection Error
• 3 Flashes – Lockout
• 4 Flashes – N/A; Reserved for future diagnostics
• 5 Flashes – Low voltage
The pattern will be repeated at intervals of 3 seconds.

17Page
COMPONENT INFORMATION
On/Off Switch
•Conrmpoweronincomingsideofswitch.Nopowercheckforblownfuse,brokenor
disconnected wire, low battery Etc.
•Powercomingintoswitchbutnotcomingout,ReplaceSwitch.
RELAY, with on/off switch turned on
•Therelayhas4posts,withwiresattached.
Left---Red with jumper Red
Rear---Red
Right---Orange/Black
Front---Orange, power out of the relay
When the on/off switch is turned but water heater not running, 3 of the posts will have power.
Left, rear and right. The flow switch (discussed next) has two small black wires coming out of
it. One black wire goes to ground, the other attaches to the orange wire on the right side of the
relay. When a hot water faucet is opened the flow switch is activated. The black wire going
to the relay loses power and the relay closes. When this happen power flows from the relay
through the front orange wire and into the ECO. If this does not happen, confirm power drop at
black wire. If power does not drop out, suspect flow valve. If power does drop, with no power to
the orange wire, replace relay.
FLOW SWITCH
The flow switch is where the cold water comes into the water heater. As the water flows through
this device a poppet or small cylinder inside the flow switch will move up from the pressure of
the incoming water. A magnet in the poppet will energize, completing the circuit in the relay.
(Discussed above) On a rare occasion the poppet will stick in the flow valve. This is indicated,
when the hot water is turned on, nothing happens. Tap or hit the flow valve to loosen the
poppet. If this fixes the problem it should not have to be replaced. It should not happen again
unless the water heater has been ideal for a long period of time. Even rarer, I have seen times
when the water heater will not shut off when the water is shut off. Again taping the flow valve
will shut the W/H down. If either of these situations happen more than once, replace the flow
valve.
To test the flow valve. Using a multimeter.
Disconnect the small black wire from the relay. Using the meter, set for continuity, attach the
red lead to the wire from the relay and ground the black wire. There will be no continuity. Turn
on the hot water and you should get a reading. If not, replace the flow valve. Another test is to
by-pass the flow switch by disconnecting the black wire from the relay and putting ground on
the relay with another piece of wire.

ECO/ (ECO-Combo, later models)
To test the ECO with a meter or test lite. When the water heater is turned on, test for power into
the switch, from the relay. If no power, go back to the previous information for the relay. If there
is incoming power, check the other side of the switch. If there is power in, but no power out,
replace the ECO. In the case of the combo switch, (white) with the push button. Push to reset, if
the water heater comes on, the problem is fixed, if not fixed, replace. If the customer complains
that the water will not get hot enough, check for the calibration of the switch. Jump the wires
from the switch. If the water heater operates properly, replace the switch. See Technical Bulletin
092813-A.
BOARD, MOTOR
When a hot water faucet is turned on, the power leaves the ECO, it goes to the board which is
always powered, from the red wire on the bottom of the board. As the power enters the board
through the orange wire it flows to the on board relay. Power leaves the board though the black
wire on the bottom of the board. The motor comes on. If the motor does not come on:
•Conrmthattheblackmotorleadisconnectedtotheboard.
•Conrmthatthewhitewireisattachedtoground.
•Disconnectboththewhiteandblackwiresandapply12voltsdirectlytothemotor,as
your power source, you may choose to connect the black wire directly to the ECO outlet
connection, when the water heater is energized.
•Ifthemotordoesnotoperate,replacemotor.Ifitdoesoperate,replacetheboard.
When the motor comes on, if you blow a fuse, check to see that the motor is not stuck or
contaminated. If the motor is not turning:
•Removetheuetube,screwonbottomofue.
•Turnmotorbyhand.Ifitisbentandrubbingonthehousing,withtheuseofascrewdriver
carefully bend the blower until it moves freely. Try again.
•Ifitiscontaminatedbywaspsorsomethingelse.Removetheuetubeandthesailswitch.
Using a screwdriver, loosen up the obstruction. Vacuum out as much as possible. Turn on
motor and let it blow the rest of the obstruction out.
•Putitbacktogetherandtryoperationagain.
If the motor or chamber have to be replaced, Girard will send the entire (Chamber and Motor)
assembly complete. This is much easier to replace than either one by itself.
SAIL SWITCH
The sail switch is activated (moves forward) when the blower comes on. When this happens it
completes a circuit into the board, through the RED WIRE. If the blower comes on, but nothing
else happens, check the sail switch:
•Ifthesailswitchisforward,testforpowerintoandoutoftheswitch.Ifnopowerout,
replace sail switch.
•Ifsailswitchdoesnotmoveforward,checktoseeifitisstuckinthebackposition.Itis
probably rubbing on the slot at the flue tube. Bend bracket until the shaft from the sail
switch is in the middle of the slot. Try again.
18Page

19Page
•Ifitisnotstuck,checkforlowvoltage,orhardtooperateswitch.Ifthewaterheatercomes
on one time, but will not start the second time, check to see that the sail switch is not stuck
in the forward position, when the water heater shuts off. If it is, adjust, as indicated above.
MORE ABOUT THE BOARD
WE HAVE TALKED ABOUT THE BORD AND THE MOTOR OPERATION. Now we will discuss the
remaining functions. There are three locations where wires enter the board:
Bottom of board:
1. Blower (BLO) black wire from board to motor.
2. Power (PWR) red wire into board. As long as the on/off switch is turned on there will be
power at this wire.
Top of Board:
On the top there are 5 wires going into the white block:
When the water heater is activated:
1. Power comes in on the orange wire from the ECO. If no power here, go back and check
ECO.
2. Red Wire, power comes from sail switch, when it is activated. No power, check sail switch.
3. Blue Wire, Light circuit. This is the LED diagnostic lite. This light will flash one time upon
ignition. It will stay on for a short time during relight and it will flash multiple times to
indicate a problem.
4. Brown Wire, when the board is activated the brown wire sends power to the gas valve. If
valve fails to open, check to confirm that all wires are connected to the valve. If wires are
connected, confirm power out of the board at the brown wire. If no power, replace board.
If there is power, do an OHMS test at each coil. Should be 30 to 50 OHMS. Not proper or
no reading, replace valve.
5. Black Wire, this is a ground wire and must be attached to the ground strap.
Gas Valve
To test for proper pressure at the gas valve, there is a tap at the front of the valve. Using a
3/16 allen wrench. Remove the plug from the valve. Install a ¼ inch barb, for the plastic
hose for the manometer. Proper pressures listed below.
Series 1
High - 10.5 IWC (Inches of water column)
Low - 7.0 IWC
Series M
High - 10.0 IWC
Low - 11.5 IWC
Before replacing the gas valve, be sure that the (main tank regulator) has been tested. In
most cases the problem is on the tank regulator, rather than the water heater valve.

20Page
WATER PRESSURE
Since a tankless water heater produces water instantly it should have at least 1 gallon a minute
through the hot water lines for good operation. The M-Series is less critical, due to the dial.
There are several factors to consider if the water pressure is low:
1. Check the RV to be sure the customer is not using a flow restrictor on the incoming water
line. In most cases they are not required, and they can reduce the flow to much.
2. Look to see if the customer is using an in line water filter. This is not a problem, unless it
is really dirty and should be replaced.
3. Be aware of the pressure in the park where you are staying. Many RV parks have very low
pressure.
If the pressure cannot be resolved, we recommend, filling the fresh water tank and using the on
board pump.
A simple way to test the water pressure, using a 1 gallon jug. Using the hot water only. Run
water into the gallon container and time how long it takes to fill the jug to 1 gallon. If the jug is
filled in less than one minute, you have over 1 gallon per minute. If the water does not fill the
jug, in 1 minute, it is less than 1 GPM.
HEAT EXCHANGER
Occasionally, you might see a slight leak at the incoming or outgoing connection on the chamber.
If this occurs, using a ¾ inch open end wrench, tighten.
On a rare occasion the chamber might develop a small leak. This is usually caused by freezing.
The M-Series includes, in all water heaters a WUD (winter use device). This built in system, is
used to protect the (water heater only), from freezing. If a hole develops in the chamber, we will
have you return the entire water heater for evaluation. During the 2 year warranty, if the WUD
switch if found to be defective we will replace the water heater a no charge. If the switch is
working properly, the customer will be responsible for the repair.
BURNERS
On rare occasions if the burners are found to be burning with a lot of yellow flame, they may be
contaminated. You may also have times when the burner will not light all 9 sections. They can
normally be cleaned by spraying air across the orifices. If more cleaning is required, you should
remove the burner for a visual inspection.
Removing the burner assembly:
1. There are 2 screws on each side of the burner. Remove these screws and the burner will
drop down.
2. Disconnect the gas line with a 9/16 open end wrench.
3. Remove the ground wire.
4. Disconnect the electrode wire from the board.
5. Simply roll the burner out of the water heater. The orifice bank can be removed (2 screws
each side) for easy cleaning.