A.O. Smith GCV Series Page 1 Service Handbook Download

Page: 1 / 44

MODELS: GCV, GCVH, GCVL, GVR, XCV, XCVL,
XGV, XVR - SERIES 200/201
GVRL, XVRL (40-Gallon Short) SERIES 202/203

06/09

316877-000

SERVICE HANDBOOK FOR

STANDARD RESIDENTIAL

FVIR GAS WATER HEATERS

http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html

Summary of Contents for GCV Series

Page 1: ...R XCV XCVL XGV XVR SERIES 200 201 GVRL XVRL 40 Gallon Short SERIES 202 203 06 09 316877 000 SERVICE HANDBOOK FOR STANDARD RESIDENTIAL FVIR GAS WATER HEATERS http waterheatertimer org How to troubleshoot gas water heater html ...

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Page 3: ...ok is intended for use by licensed plumbing professionals and reference should be made to the Installation Instructions and Use Care Guide accompanying the product This handbook contains supplemental information to the Installation Instructions and Use Care Guide When servicing residential water heaters it is essential that you return the unit to a safe condition before you leave the site All orig...

Page 4: ...oid all ignition sources if you smell Natural or LP gas Do not expose water heater control to excessive gas pressure Use only gas shown on rating plate Maintain required clearances to combustibles Keep ignition sources away from faucets after extended period of non use Read instruction manual before installing using or servicing water heater ...

Page 5: ...the capacity of the water heater See sizing guide on p 25 You may also use the volume test on page 34 to analyze your hot water needs If necessary install a water heater with greater capacity Gas Control Valve Thermostat set too low Turn temperature dial to desired temperature as described on p 24 Sediment or lime in the tank Drain p 17 Determine if water treatment is needed p 29 WATER LEAKAGE Con...

Page 6: ...N 6 WATER LEAKAGE Thermostat does not shut off Check the Gas Control Valve Thermostat as described on p 20 21 Drain valve dripping leaking Back flush to clean out sediment replace if necessary Tank Leak Check Leakage Checkpoints described on p 25 ...

Page 7: ... 20 REPLACING THE THERMOCOUPLE AND GAS CONTROL VALVE THERMOSTAT 21 23 Removing the Manifold Burner Assembly 21 Removing the Burner from the Manifold Burner Assembly 21 Replacing the Thermocouple 21 Replacing the Manifold Burner Assembly 22 Removing and Replacing the Gas Control Valve Thermostat 23 ADJUSTING THE TEMPERATURE ON THE GAS CONTROL VALVE THERMOSTAT 24 GAS WATER HEATER SIZING GUIDE 25 LEA...

Page 8: ... from flammables and flammable vapors The water heater must be installed according to all local and state codes or in the absence of local and state codes the National Fuel Gas Code ANSI Z223 1 NFPA 54 current edition INSTALLATION OF RESIDENTIAL GAS WATER HEATER See Labels and Installation Instructions and Use Care Guide for clearances NOTE If on a well system the expansion tank should be set to t...

Page 9: ... Foam Fill Hole Draft Hood Temperature Pressure Relief Valve Dip Tube Flue Baffle Gas Control Valve Thermostat Drain Valve Anode Rod Flue Tube Jacket Temperature Probe High Limit Probe Gas Control Knob On Pilot Off Water Temperature Dial Water Temperature Dial Gas Control Knob Off Pilot On Setting Indicator Index Bar Thermal Switch Wire Leads with Connectors some models Reset Button Robertshaw Gas...

Page 10: ...lot Orifice Ferrule Pilot Nut Pilot Tube Pilot Bracket DO NOT operate the water heater without the pilot and burner orifices installed NOTE The base of the Thermocouple must be flush with the base of the pilot bracket Pilot Assembly View Piezo Igniter Tip BASIC INSTALLATION OPERATION Gas Control Knob Reset Button Pilot Flame Safety Valve Safety Valve RobertShaw Gas Control Valve Thermostat Shown F...

Page 11: ... the gas control knob to the pilot position and depress the gas control knob Reset button on Robertshaw Gas Valves When depressed gas will flow to the pilot burner only You then have to manually ignite this pilot gas using the piezo igniter button When the pilot is lit the flame must heat the thermocouple until it generates sufficient voltage to the gas valve to allow you to release the knob while...

Page 12: ...ature around the thermostat probe Also short repeating heating cycles caused by small hot water uses can cause temperatures at the point of use to exceed the thermostat setting by up to 30 F Water Temperature Time to Produce 2nd 3rd Degree Burns on Adult Skin 160 F 71 C About 1 2 second 150 F 66 C About 1 1 2 seconds 140 F 60 C Less than 5 seconds 130 F 54 C About 30 seconds 120 F 49 C More than 5...

Page 13: ...d technician using the local and state codes or in the absence of local and state codes the National Fuel Gas Code ANSI Z223 1 NFPA 54 current edition and or the installation instructions Examples of a qualified technican include gas technicians authorized gas company personel and authorized service persons Failure to so do can result in death or carbon monoxide poisoning IMPORTANT Air for combust...

Page 14: ...pening If the design and free area are not known it can be assumed that most wood louvers will allow 20 25 of free area while metal louvers and grilles will allow 60 75 of free area Louvers and grilles must be locked open or interconnected with the equipment so that they are opened automatically during equipment operation Keep louvers and grilles clean and free of debris or other obstructions Mini...

Page 15: ...t to a chimney make sure the chimney passageway is clear and free of obstructions The chimney must be cleaned if previously used for venting solid fuel appliances or fireplaces Also consult local and state codes for proper chimney sizing and application or in the absence of local and state codes the National Fuel Gas Code ANSI Z223 1 NFPA 54 current edition The connector must be installed above th...

Page 16: ...allow proper venting Common combined venting is allowable with vertical type B vent systems and lined masonry chimneys as long as proper draft for the water heater is established under all conditions of operation CAUTION DO NOT common vent this water heater with any power vented appliance The following figures are examples of vent pipe system installations and may or may not be typical for your sp...

Page 17: ...r as directed by the lighting instructions on the front of the water heater If the water heater is going to be shut down for an extended period the drain valve should be left open IMPORTANT Condensation may occur when the cold tank is first heated and should not be confused with a tank leak Filling the Water Heater Never use this water heater unless it is completely full of water To prevent damage...

Page 18: ...ure regulator reduce setting on existing regulator manifold gas pressure is more than 3 inch W C from values indicated on gas valve ensure there is adequate supply gas pressure e nsure the main burner orifice is the correct size for the water heater model being tested if the above tests have been performed and the results were correct replace the gas control valve Combustion Air Test The Installat...

Page 19: ...g filter for any dust or debris that may have accumulated on the filter screen NOTE If the water heater is located in an area that is subjected to lint and dirt it may be necessary to check the base ring filter more frequently 2 Follow the Lighting Instructions to turn off the water heater and allow it to cool for 10 minutes before attempting to clean the base ring filter 3 Use a vacuum cleaner wi...

Page 20: ... Thermostat Test Thermal Switch Models The following test will check the gas control valve thermostat s ECO TCO Energy Cut Off Thermal Cut Off NOTE This test applies to gas valves with wire leads that attach to the thermal switch on the manifold door Remove both wire leads from the TCO thermal cut 1 off switch and jumper the two leads to complete the circuit Once the test is complete remove the ju...

Page 21: ... valve This valve is typically located beside the water heater Note the position of the shut off valve in the open on position then proceed to turn it off 2 On the lower front of the water heater locate the gas control valve thermostat Before performing any maintenance it is important to turn the temperature dial on the gas control valve thermostat to its lowest setting 3 On top of the gas control...

Page 22: ... create a seal between the manifold door and the combustion chamber 6 During the following procedure do not cross thread or apply any thread sealant to any of the fittings listed below First reconnect the manifold tubing to the gas control valve thermostat NOTE L P gas systems use reverse left hand threads on the manifold tube NOTE If a ferrule nut needs to be installed for the pilot tube locate t...

Page 23: ...zed pipe into the inlet and use it to turn the gas control valve thermostat counterclockwise Do not use pipe wrench or equivalent to grip body Damage may result causing leaks Do not insert any sharp objects into the inlet or outlet connections Damage to the gas control valve thermostat may result Replacing the Gas Valve 1 To replace the gas control valve thermostat reassemble in reverse order When...

Page 24: ...the thermostat see following figure Using the lowest hot water temperature that meets your needs will also provide the most energy efficient operation of the water heater Never allow small children to use a hot water tap or to draw their own bath water Never leave a child or handicapped person unattended in a bathtub or shower NOTE A water temperature range of 120 F 140 F 49 C 60 C is recommended ...

Page 25: ...aw efficiency of a gas or electric water heater storage tank is considered to be 70 6 152 4 mm MAXIMUM AIR GAP A C B D E F G H I A Water at the draft hood is water vapor which has condensed out of the combustion products This is caused by a problem in the vent B Condensation may be seen on pipes in humid weather or pipe connections may be leaking C The anode rod fitting may be leaking D Small amou...

Page 26: ... MINERAL BUILD UP 28 ALUMINUM HYDROXIDE 29 CONDENSATION 30 DISCOLORED WATER 31 SMELLY WATER 32 CHLORINATION PROCEDURE 33 NOT ENOUGH HOT WATER 34 THERMAL EXPANSION 35 36 LEAKING TEMPERATURE AND PRESSURE RELIEF VALVE 37 INSULATION BLANKETS 38 ...

Page 27: ...mber of ways The most common are Expanded Tank Shell This can be demonstrated by measuring the circumference at various locations along the shell Pressures in excess of the maximum design working pressure can cause permanent deformation of the shell NOTE The continuous expansion of the tank shell may cause the tank to rupture at a welded seam Collapsed Flue Tube This will choke off the ability to ...

Page 28: ...elements boiling it to steam THE FIX Treatment of a limed up heater is relatively simple Since CaCO3 is a base the easiest way to dissolve it so it can be flushed from the heater is with an acid The most commonly used is phosphoric acid at a food grade level Two available treatments are Mag Erad and Un Lime Any well stocked plumbing supply house should have a deliming solution available The direct...

Page 29: ...ter 2 Remove the anode 3 Flush the tank thoroughly with water 4 Replace the aluminum anode identifiable by smooth surface on plug with magnesium anode identifiable by weld bead on plug If tank is new with lime build up to any degree 1 Turn off the heater 2 Drain the heater 3 Remove the anode 4 Add UN LIME to the tank 20 40 gallon models use 3 gallons of UN LIME 41 65 gallon models use 5 gallons of...

Page 30: ...ng every hour of operation Condensate is often mistaken for leaking Newer heaters will condensate more than older heaters because modern water heaters are much more efficient than their predecessors The newer heaters utilize as much of the energy out of the main burner flame as possible This lowers the flue gas and tank storage temperature and closer to the dew point temperature DIAGNOSIS To disti...

Page 31: ...iscolored water is the end result of the bacteria feeding process Water heaters and storage tanks usually require new anode rods as presence of iron bacteria contributes to premature anode failure The requirements for the bacteria to thrive are Elevated levels of iron and manganese in the water Water with little or no dissolved oxygen Temperatures below 138 F Items that can increase the potential ...

Page 32: ...the tank c water with little or no dissolved oxygen d and temperatures below 138 F Items that can increase the potential for this bacteria are a water softeners b well water c and long periods of no water movement Other factors that may contribute to smelly water Chlorides of Magnesium and Calcium leave a bitter taste Chloride of Sodium produces a salty taste Sulfates 50 ppm gives a medicinal tast...

Page 33: ...for every 25 gallons of tank capacity STEP 7 Reinstall anode rod s after inspecting and replacing as needed STEP 8 Open cold water supply valve and refill the system Then draw the water to every hot water fixture until the smell of chlorine is detected Operate dish and clothes washers until a noticeable amount of the chlorine is detected as well All hot water lines must receive treatment STEP 9 Le...

Page 34: ...inute 10 seconds 6 gallons per minute 15 seconds 4 gallons per minute 20 seconds 3 gallons per minute 30 seconds 2 gallons per minute STEP 2 Using a thermometer turn on the hot water and time how long it takes for the water temperature to drop 30 degrees Gallons Per Minute GPM Flow Rate 1 5 2 2 5 3 3 5 4 5 6 30 Gallon Tank 14 min 10 min 8 min 7 min 6 min 5 min 4 min 3 min 40 Gallon Tank 18 min 14 ...

Page 35: ...essure reducing valves PRV is another cause PRVs are designed to conserve water and prolong fixture life Many PRVs also act as very effective check valves Again do not remove them Water softeners in the system may also act as back flow preventers TEST Follow these easy steps to diagnose thermal expansion Turn the heater thermostat all the way down and install a water pressure gauge with dead hand ...

Page 36: ...increase only slightly then hold steady throughout the recovery cycle The expanded water is flowing back from the heater and into the pressurized storage bladder of the expansion tank Air pressure will force this water out of the expansion tank into the supply once usage resumes DO NOT DEPEND ON THE TEMPERATURE PRESSURE VALVE T P VALVE TO HANDLE THERMAL EXPANSION The T P valve manufacturers design...

Page 37: ...the relief valve should be the same or less than the certified working pressure of the tank generally 150 psi and be below the lowest maximum working pressure rating of any system components Once the pressure in the tank reaches the valve s pressure rating it will slightly open relieving the pressure Relieving of pressure can be noted as dribbling or weeping water from the relief valve If an incor...

Page 38: ... to follow these instructions can restrict the air flow required for proper combustion resulting in fire asphyxiation serious personal injury or death Do not cover the outer door thermostat or temperature pressure relief valve When installed the insulation blanket will cover important safety and operation labels Obtain new warning and instruction labels from the Technical Information Center listed...

Page 39: ...perature from its coldest inlet water temperature to the desired hot outlet setting Typically this is assumed to be 40 degrees entering water 120 degrees desired stored water or 80 degrees temperature rise Thermal efficiency is approximately the amount of generated BTU British Thermal Units which enters the water A percentage of the total BTU passes out through the vent piping Water cannot for all...

Page 40: ...cted of a glass lining bonded to the steel This prevents water to metal contact and rusting of the tank An anode rod will be installed within the tank The hex head plug end of the anode is visible on the top of the water heater This metal rod offers secondary protection of the tank against corrosion where the application of glass is not possible threaded tank openings These areas will have small a...

Page 41: ...41 NOTES ...

Page 42: ...42 NOTES ...

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Page 44: ... WARRANTY QUESTIONS SHOULD BE DIRECTED TO THE LOCALDEALER FROM WHOM THE WATER HEATER WAS PURCHASED IF YOUARE UNSUCCESSFUL CONTACTAO SMITH WATER HEATERS RESIDENTIALTECHNICALASSISTANCE AT 1 800 527 1953 OR WWW HOTWATER COM ...

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A.O. Smith GCV Series, Service Handbook

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