Atwood Mobile Products 94605 User Manual

September 2003

INTRODUCTION

The 2004 edition of the Atwood Water Heater Service Manual is a resource created to help service technicians identify Atwood product by serial number, diagnose service problems and efficiently and effectively process warranty claims.

In 2003, Atwood relocated the Switch, Thermostat and ECO that was installed on the back of combination 6 and 10 gallon Gas/Electric Water Heaters. A double switch is now located inside the RV for convenience and a joint ECO and T-Stat is located on the gas side of the water heater. This leaves only the relay and heating element on the backside of the water heater.

Each of the manuals within this series offers a general overview of the product as well as more specific product information. For each product within the manual, you will find model identification, recommended tools and equipment, a sequence of operation, warnings, annual maintenance procedures, parts and troubleshooting guides, warranty procedures, flat rate schedules, and replacement part reference charts.

Due to the rapidly changing personal computer revolution we have placed troubleshooting information in a variety of places to make sure that the most accurate information is available. The best place to find the current information about Atwood products is our website: www.atwoodmobile.com. At our website brochures may be downloaded, trouble shooting guides reviewed and the latest information bulletins can be read. In addition all Atwood Authorized Service Centers are listed on our site, accessible via an easy-to-use search system.

Service for all Atwood products is handled out of our Rockford location. Should you have any questions regarding our products or the information contained in this manual simply dial 1-800-825-4328. Be sure to have the Model and Serial Number when

you call.

Atwood Service Department

Disclaimer: The data presented in this publication is obtained from the most reliable sources, and is believed to be accurate as of the date of publication. Responsibility for typographical errors or omission of data cannot be assumed by the publishers.

NOTES

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TABLE OF CONTENTS

Atwood Water Heaters

Atwood Letter 1 Aftermarket Model Identification 4 Pilot Models

Questions 5 Model Number Explanation / Features 6 Recommended Tools & Equipment 7 Gas Thermostat Controls & Pilot Assemblies 8 Pilot Sequence of Operation 9 Pilot & Main Burner 10 Trouble Shooting Guide 11 Engine Heat Exchange System / Aftermarket Heating Elements 12 Bolt-In Heating Element, Thermostat & ECO / 110 VAC Trouble Shooting Wiring Schematic 13 Screw-In Heating Element, Thermostat & ECO / 110 VAC Trouble Shooting Wiring Schematic 14

Electronic Ignition Models

Questions 15 Model Number Explanation / Features 16 Recommended Tools & Equipment 17 DSI Sequence of Operation 18 Trouble Shooting Guide - Electronic Ignition 19-20 Information Guide - Intermittent Ignition 21-22 Potted Channel Circuit Boards / Thermal Cut Off Device / Thermostat 23 Wiring Schematics 24

General Water Heater Information

Questions 25 Pressure Temperature Relief Valve / Water Heater Tank Corrosion / Atwood Clad Tank 26 Flushing Tank / Winterizing Instructions 27 Water Heater Terminology 28

Warranty 29 Warranty Procedures 29 Return Goods Policy ( Flat Rate Schedule 31 Pilot Water Heater Parts Breakdown 32-34

Replacement Part Reference

G10B, G10C / G610-3B, GH610-3 / G4SM / G6A-2, G6A-3, G6A-6, G6A-6P, G6A-7, G6A-7P / GC6A, GC6A-3, GC6A-6, GC6A-7 / GH6-3, GH6-6, GH6-7 / GC6AA-7, GC6AA-7P / GC6AA-8, GC6AA-8P / G610-3, GC10-1, GC10-2, GC10-2P / GC10A-2 / GC10A-2P / G10-1, G10-1P, G10-2, G10-2P

Electronic Ignition Water Heater Parts Breakdown 35-37 Replacement Part Reference

G610-3E, GH610-3E / GCH6-4E, GCH6-6E, / GC6A-7E / GC6AA-7E / GC6AA-8E / GC6AA-9E, GC6AA-10E G6A-2E, G6A-3E, G6A-4E, G6A-6E, G6A-7E, G6A-8E / G6A-3E, GH6-3E / GH6-4E, GH6-6E, GH6-7E, GH6-8E / GCH6A-7E, GCH6A-8E, GCH6A-9E / GCH6A-10E / GCH10A-2E, GCH10A-3E / GCH10-4E / G10-1E / GH10-2E, GH10-3E / GC10-1E, GC10-2E / GC10A-2E /

GC10A-3E / GC10A-4E

Service Tank Kit Part Numbers 38 Marine Water Heater Parts Breakdown 39

Atwood Training Tapes and Manuals ORDER BLANK

RETURN ADDRESS) 30

Aftermarket Gas Water Heaters

Includes Doors & Switches (when appropriate)

G6A-7 ----------------------------------6 gal. w/pilot GC6AA-8 ------------------------------6 gal. combo w/pilot GC6AA-10E GCH6A-10E G6A-8E GH6-7 ---------------------------------- GH6-8E G10-2----------------------------------10 gal. w/pilot GC10A-2------------------------------10 gal. combo G10-3E GC10A-4E ----------------------------10 gal. electronic combo GCH10A-4E --------------------------10 gal. electronic combo w/heat exchange

----------------------------6 gal. electronic gas combo

----------------------------6 gal. electronic gas combo w/heat exchange

--------------------------------

--------------------------------6 gal. electronic w/heat exchange

--------------------------------10 gal. electronic

6 gal. electronic 6 gal. w/pilot, heat exchange

Marine Water Heaters

EHM6-4WFHX ------------------------4 gal. marine, front heat exchange & special hook-up EHM6-SMFHX ------------------------6 gal. electric marine w/heat exchange H6-FHX --------------------------------6 gal. marine special EHM6-ATC EHM6-SMSS --------------------------6 gal. marine, rear heat exchange & special hook-up EHM11-SSDHXT --------------------6 gal. marine, stainless steel dual heat exchange tube EHM11-SMFHX EHM11-SST--------------------------11 gal. electric, heat exchange stainless steel tank H11-FHX------------------------------11 gal. marine special EHPM10 ------------------------------11 gal. electric marine w/special tube EH-20 E20 ------------------------------------20 gal. electric marine

----------------------------6 gal. marine, heat exchange & temp. control

--------------------11 gal. electric marine w/heat exchange

----------------------------------20 gal. electric marine w/heat exchange

Marine International Water Heaters

EHM6-220-FHX ----------------------6 gal. marine, heat exchange, 220 volts EHM6-220SST------------------------6 gal. marine, heat exchange, 220 volts, stainless steel housing EHM6-220-FHX ----------------------6 gal. marine, heat exchange, 220 volt, 1000 watt element EHM11-220 EHM11-220SST --------------------11 gal. marine, heat exchange, 220 volts, stainless steel housing EHM11-220SS-4WFHX ----------11 gal. marine, heat exchange, w/special hook-up EHM11-220SS-IMFHX EH20-220 ----------------------------20 gal. marine, heat exchange, 220 volts E20-220

--------------------------11 gal. marine, heat exchange, 220 volts

------------11 gal. marine, heat exchange, 220 volt, 1000 watt element

------------------------------20 gal. marine, 220 volts

European Water Heaters

EURI6A-6E ----------------------------6 gal. International Electronic 3-bar valve EURIH6-6E ----------------------------6 gal. International Electronic w/heat exchange EURICH6-6E --------------------------6 gal. International Electronic Combo w/heat exchange

PILOT MODELS

QUESTIONS

The following questions should be answered during this portion of the manual:

· Are the Robertshaw and White Rodgers thermostat gas control valves inter-changeable?

· What is the minimum gas pressure required for proper water heater operation?

· Where on the water heater gas control can gas pressure be tested?

· Can the pilot flame be adjusted?

· What is minimum millivolt output of the thermocouple required for proper gas control operation?

· How can you test a thermocouple?

· How tight should the thermocouple connection be at the gas control?

· What is an E.C.O., where is it located and what is its function?

· What is a proper main burner air shutter adjustment?

· What is the proper control and main burner alignment?

· How can you easily check the calibration of a control?

Atwood 6 and 10 gallon Pilot Water Heaters

Atwood water heaters are designed and approved for use only in recreation vehicles (travel trailers, 5th wheels, motor homes, etc.). They are offered in two sizes: 6 and 10 gallon capacities.

TYPE OF GAS IGNITION -

This unit is ignited outside of the trailer by a match, piezo ignitor or other ignition device. The water temperature is adjustable at the thermostat control.

EXPLANATION OF MODEL NUMBER:

Pilot Models

GCH 6AA- 7 P

Pilot Relight Version Type of heating element

(GC_ A - _ = bolt on, GC_ A A-_ = screw in) Gallon capacity (6 or 10) Engine Heat Exchange

Combination gas and 110 Propane Gas

NOTE: When replacing the element on a combination gas/110 VAC unit, always check the back

of the heater for the type of element it has. It will either be a bolt-on or screw-in element. They are no interchangeable.

VAC electric

FEATURES

•

All units operate on propane gas.

•

A heat exchange option is available for motor homes. The water heater tank must have factory equipped heat exchange tubes welded on it already. They cannot be added later. A new water heater tank with this option is the only way to obtain this feature.

•

Skin mounting allows the water heater to be hooked up with plumbing and electrical before the sidewall is erected.

•

The tank has a clad aluminum lining that protects against corrosion and does not need to be replaced on a yearly or more frequent basis like anode rods do. A more detailed explanation of cladding is found in the back of this manual.

•

95% of all servicing can be done on the outside of the water heater. 110 VAC heating components are the exception since they are located on the back of the water heater inside the trailer.

•

A flush flange is available for all models. This makes the access door flush with the trailer sidewall.

•

There are multiple protection features in the form of a pressure-temperature relief valve, a limit switch in the gas thermostat and an externally sealed combustion chamber.

•

On combination water heaters, the gas mode and the 110 VAC heating mode can be operated at the same time since each mode has its own thermostat.

•

Both the six and ten gallon units have the lightest weight in the industry.

•

On all trailers purchased after June 1, 1997 Atwood Limited Warranty is for a period of two years. This includes all reasonable labor charges.

•

We have 650+ Service Centers throughout the United States.

Recommended Tools and Equipment

Manometer connection

Correct water level

Fill here

U-Tube Manometer - This is the most accurate device for measuring gas pressure. If you use a dial-type manometer, it should be calibrated periodically with this type of manometer.

Thermostat Wrench - This tool allows for easier and safer removal of the gas thermostat control. An adjustable version for different size controls is available through most RV distributors or you may fabricate one from angle iron. We do not recommend using a pipe wrench because it may damage the control causing it to go out of calibration.

U-TUBE MANOMETER

with 1/8” pipe nipple

THERMOSTAT WRENCH

Multi-meter - This is the most versatile meter and will test AC voltage and continuity. A continuity test can be used to test for a blown E.C.O. on a gas control.

Magnet Assembly Thermocouple Tester - This assembly can be obtained at an electronics or hardware store. This same assembly can also be removed from a Robertshaw control. It will verify if a thermocouple is good. For testing, screw a thermocouple into the tester, heat the thermocouple for 25 seconds and then press the plunger down. If the plunger pops up in less that 25 seconds, the thermocouple is faulty.

MULTI-METER TO TEST

AC VOLTAGE AND CONTINUITY

Common Hand Tools - 1/8˝ and 1/4˝ nut drivers, open end wrenches, flat blade and Phillips screw drivers. Leak Test Solution - A solution that bubbles when applied to gas fittings or connections showing when a gas

leak is present.

MAGNET ASSEMBLY TO TEST

THERMOCOUPLE

Gas Thermostat Controls and Pilot Assemblies

Only two makes of gas controls have been used on our pilot model water heaters. They are the Robertshaw “Unitrol” and White Rodger (formerly Jade or ITT).

The Robertshaw control came in two different sizes of gas inlets: 3/8˝ inverted flare and 3/8˝ N.P.T. The inverted inlet control is no longer available. Therefore, the water heater gas line connection will have to be modified to 3/8˝ N.P.T. in order to use the current Robertshaw control.

The White Rodger control is the valve we are using on all production today. Formerly it had a 3/8˝ N.P.T. inlet. Now it is only available with a 1/4˝ inlet. This improvement eliminates the adapter fitting into the control allowing the use of only a single 45 degree elbow (3/8˝ flare x 1/4˝ N.P.T.). If you are replacing a current 1/4˝ inlet model control with a earlier model 3/8˝ inlet control you may have in stock, the adapter fitting that mates the control and elbow fitting is still available.

Although the controls appear quite different in size, the White Rodger and Robertshaw control are interchangeable. Their manifolds will both line up with the burner tube properly.

Both controls have a port to test gas pressure through the valve. This can be accomplished by removing the cover screw and inserting a 1/8” pipe nipple. After attaching your manometer hose to this fitting, the manometer should register 10” W.C. through the valve while it is operating.

ROBERTSHAW “UNITROL”

• 3/8˝ Inverted inlet

3/8˝ N.P.T. outlet

(no longer available)

WHITE RODGERS (JADE, ITT)

• 3/8˝ N.P.T. outlet

(no longer available)

• 1/4˝ N.P.T. inlet

• 3/8˝ N.P.T. inlet

3/8˝ N.P.T. outlet

There are two main pilot assemblies that you will encounter in the field.

The first is an earlier model Robertshaw pilot assembly with a 1/4˝ pilot gas line that mounted on the left side of the main burner.

The current pilot is the Jade assembly with a 1/8˝ pilot gas line and it mounts on the right side of the main burner.

The Robertshaw pilot is no longer available and the Jade pilot must be substituted. When installing a Jade assembly in place of a Robertshaw assembly, if there is not a location on the right side of the main burner to mount the Jade pilot, a new burner that has the proper mounting holes will have to be purchased.

3/8˝ N.P.T. outlet (replaces all Robertshaw and Jade controls)

Note: The size of the gas line does not have any affect on the size of the pilot flame. Only the gas pressure and pilot orifice regulate the height of the pilot flame.

JADE ROBERTSHAW

(obsolete, replace with Jade)

PILOT OPERATION

Pilot Flame

Thermocouple

ON/OFF Pilot Knob

Air Shutter

ONE SHOT E.C.O. 190°

Gas Inlet 11" W.C. Pressure

JADE CONTROL SYSTEM

Temperature Lever

Pilot Orifice (inside)

• Gas Pressure 11˝ W.C. to control is necessary. Set with two gas appliances running.

Pilot Sequence of Operation



• Gas Control supplies gas to pilot orifice when control ON/OFF pilot knob is held at pilot position.

• Pilot Orifice meters gas to heat thermocouple. Flame should be high enough to engulf the

• Thermocouple generates millivoltage to the gas control’s magnet assembly.

• Magnet when it receives 12 millivolts or more it allows gas to flow freely to pilot without

• E.C.O. passes millivolts through the gas control and back to thermocouple. Trips

MAIN BURNER OPERATION

• Gas Control supplies gas to main burner when control knob is set to “ON” position and the

• Main Burner Orifice meters gas through burner tube.

• Main Burner pilot ignites gas when it reaches end of this tube. Flame height adjusted by sliding air



thermocouple.



holding pilot knob.



permanently open if water temperature exceeds 190°F.

temperature lever is set to desired temperature after pilot is lit.

shutter. Ideal setting is 1/4 way open (.20˝). Flame should be primarily blue with

a trace of yellow.



• Temperature Knob setting of knob determines burner cycle and water temperature. Temperature range is 70°F - 140°F.

Pilot and Main Burner

Pilot Flame

Thermocouple

On/Off Pilot Knob

Air Shutter

Temperature Lever

Flame Spreader

Burner Tube

Gas Valve

Orifice Holder

Main Burner Tube

Pilot Adjustment

Only the gas pressure, gas valve and the pilot orifice regulate the height of the pilot flame. Early model gas controls have a pilot adjustment screw, but this screw has very little effect on the pilot. The pilot adjustment has been removed from the current White Rodger control. The flame should be high enough to engulf the thermocouple at all times. A pilot flame any larger could blow the E.C.O. in the gas control. This is typically the result of enlarging the pilot orifice hole with a pin or similar item. For further corrective measures, refer to the trouble-shooting guide.

Main Burner Adjustment

The gas pressure, air shutter cleanliness of the burner tube and orifice regulate the main burner flame. The main burner flame should be mainly blue with a trace of yellow and fairly quiet. If it is not, adjust the gas pressure to 11˝ W.C., ensure that the main burner air shutter is 1/4 way open and verify that the main burner flame spreader is square to the end of the main burner. For further corrective measures, refer to the trouble-shooting guide.

(orientation found in water heater)

Main Burner Alignment

The manifold and main burner should be as perfectly aligned as possible. In other words, the gas valve should be rotated at the same angle as the main burner tube. If it is not, rotate the gas control and/or the orifice holder so that the orifice disperses gas straight down the center of the burner tube. If the valve must be backed off any, check for water leaks at the coupling the control screws into before you operate the water heater.

Pilot Water Heater

TROUBLE SHOOTING GUIDE

Guides are only intended for use on Atwood Atwood®training. This guide should be used in conjunction with the appropriate Instruction Manual provided with the product and any applicable Industry standards. This is not intended to be a complete list. Please direct questions concerning service of Atwood

CAUSE SOLUTION

products to 800-825-4328 before proceeding.

products by service technicians who have successfully completed

Effective: 5/26/98

PILOT OUTAGE

Gas pressure incorrect --------------------------Set pressure to a minimum of 11˝ W.C. with two or more appliances running Blocked “U” tube --------------------------------Remove obstruction Improper main burner alignment --------------Re-align main burner and main burner orifice holder and gas valve Improper air adjustment ------------------------Adjust main burner air shutter approximately 1/4 open Weak thermocouple------------------------------Replace thermocouple Poor pilot flame ----------------------------------Clean or replace pilot orifice Weak gas control magnet ----------------------Replace gas control Defective E.C.O. in control ----------------------Replace gas control and check the pilot flame. It should be high enough to engulf

the thermocouple at all times.

PILOT OUTAGE WHEN BUTTON OR KNOB IS RELEASED

Thermocouple not hot --------------------------Hold button or knob for 30 seconds before releasing Thermocouple loose ----------------------------Tighten connection at gas control Weak thermocouple------------------------------Replace thermocouple Weak gas control magnet ----------------------Replace gas control Defective E.C.O. in control ----------------------Replace gas control

MAIN BURNER WILL NOT IGNITE

Blocked main burner orifice --------------------Clean or replace orifice Main burner flame spreader mis-alignment --Square flame spreader to end of main burner Blocked main burner ----------------------------Remove blockage Improper air adjustment ------------------------Adjust main burner air shutter approximately 1/4 open Blocked “U” tube --------------------------------Remove blockage Gas control out of calibration ------------------Replace gas control

ERRATIC MAIN BURNER FLAME

Improper gas pressure --------------------------Set inlet pressure to a minimum of 11˝ W.C. with two or more appliances running Improper air adjustment ------------------------Adjust main burner air shutter approximately 1/4 open Partial blockage of main burner----------------Remove blockage Partial blockage of main burner orifice--------Clean or replace orifice Flame spreader misaligned----------------------Re-align spreader or replace main burner Blockage in “U” tube ----------------------------Remove blockage Poor gas supply----------------------------------Replace gas supply Exhaust grille blocked --------------------------Remove blockage Improper main burner alignment --------------Re-align main burner, main burner orifice holder and gas valve

SMOKING AND SOOTING

Gas pressure incorrect --------------------------Set pressure to a minimum of 11˝ W.C. with two or more appliances running Poor gas supply----------------------------------Replace gas supply Improper pilot flame ----------------------------Clean or replace pilot orifice Improper air adjustment ------------------------Adjust main burner air shutter approximately 1/4 open Flame spreader mis-aligned --------------------Re-align or replace main burner Blocked main burner ----------------------------Remove blockage Improper main burner alignment --------------Re-align main burner, main burner orifice holder and gas valve Blocked “U” tube --------------------------------Remove blockage

INSUFFICIENT WATER TEMPERATURE

Temperature selector out of place--------------Re-set to desired position Bypass levers improperly positioned ----------Reposition levers Improper air adjustment ------------------------Adjust main burner air shutter approximately 1/4 way open Partial main burner blockage ------------------Remove blockage Improper main burner adjustment ------------Re-align main burner and main burner orifice holder Flame spreader mis-aligned --------------------Re-align or replace main burner Blocked “U” tube --------------------------------Remove blockage

Engine Heat Exchange System

Customer supplied SAE 053 A type

"E" hose clamp

or evuivalent

Heat Exchanger Tubes

Annualar Grove

Heat Exchanger

Tubes

Coolant System Hose (5/8" dia. SAE 20R3 or equivalent)

Customer supplied tee

The engine heat exchange system allows a motor home to heat the water while traveling. This convenient option allows you to arrive at your destination with hot water. Operating a pilot or electronic water heater on gas while in transit is a dangerous practice.

This system consists of a U-shaped aluminum tube that is attached to the outside of the tank with welds. SAE hoses are attached to both ends of this tube and are spliced into the engine coolant system.

When the engine is running, the hot coolant flows past the tank through this tube and by means of heat transfer through the welds, heating the water. The design of this system will not allow the water to reach a boiling point. It will typically heat the water to about 130° F. in about 2-3 hours of driving.

Aftermarket Heating Elements

WARNING



EXPLOSION / BURN INJURY

• Aftermarket heating elements can lack critical safety controls.

• Use of these devices can lead to an out of control heating of water tank and a

YOU DO NOT NEED AN AFTERMARKET HEATING ELEMENT ON AN ATWOOD WATER HEATER ELEMENT DEVICES MAY ALSO RESULT IN DAMAGE TO COMPONENTS OR WATER HEATER. Atwood’s written warranty states

- “failure or damage resulting from any alteration to our water heater is the owner’s responsibility”. ANY

ALTERATION, LIKE THE ADDITION OF AN AFTERMARKET HEATING ELEMENT DEVICE, WILL VOID THE WARRANTY.

catastrophic wet side explosion.

. THE USE OF AFTERMARKET HEATING

• Temperatures produced by these heating elements can exceed the 190˚F. limit of the ECO on pilot model gas control valves. This gas control valve contains a one-shot ECO. When this ECO blows, the control is completely non-functional and must be replaced.

THIS WILL BE A NON-WARRANTABLE SITUATION.

• When Aftermarket heating elements are inserted into the drain plug, customers are more prone not to flush their tanks. Not flushing the tank accelerates tank corrosion on both our pilot and electronic ignition water heaters creating a situation where the tank may have to be replaced.

BE A NON-WARRANTABLE SITUATION.

THIS WILL

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