A.O. Smith GAHH-50 manual

1 This water heater complies with ANSI Z21.10.1-current edition regarding the accidental or unintended ignition of fl ammable vapors, such as those emitted by gasoline. For Y our Safety AN ODORANT IS ADDED T O THE GAS USED BY THIS W A TER HEA TER. • Safety Instructions • Installation • Operation PRINTED IN THE U.S.A 0410 P ART NO. 315456-002[...]

2 T ABLE OF CONTENTS W ater Heater Safety .............................................................................................................................. ............................................. 1-4 Safe Installation, Use and Service ................................................................................................[...]

3 SAFE INST ALLA TION, USE AND SER VICE Y our safety and the safety of others is extremely important in the installation, use and servicing of this water heater . Many safety-related messages and instructions have been provided in this manual and on your water heater to warn you and others of a potential hazard. Read and obey all safety messages an[...]

4 Fire or Explosion Hazard Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance. Avoid 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 [...]

5 TYPICAL INST ALLA TION GET TO KNOW YOUR W A TER HEA TER - GAS MODELS A V ent Pipe B Draft hood C Anode (Not Shown) D Hot W ater Outlet E Insulation F Gas Supply Piping G Manual Gas Shut-off V alve H Ground Joint Union I Drip Leg (Sediment T rap) J Inner Door K Outer door L Union M Inlet W ater Shut-off V alve N Cold W ater Inlet O Inlet Dip T ube[...]

6 INST ALLING YOUR GAS W A TER HEA TER Important Information About This W ater Heater This gas water heater was manufactured to voluntary safety standards to reduce the likelihood of a flammable vapor ignition incident. New technology used in meeting these standards makes this product more sensitive to installation errors or improper installation e[...]

7 Location Requirements Carbon Monoxide Poisoning Hazard W ARNING Do not install in a mobile home. Doing so can result in carbon monoxide poisoning and death. The FVIR System is designed to reduce the risk of flammable vapor-related fires. Flammable liquids (such as gasoline, solvents, propane, etc,) emit flammable vapors which can be ignited by a [...]

8 IMPORT ANT : The water heater should be located in an area where leakage of the tank or connections will not result in damage to the area adjacent to the water heater or to lower floors of the structure. Due to the normal corrosive action of water , the tank will eventually leak after an extended period of time. Also any external plumbing leak, i[...]

9 Manual Gas Shut-Off Valve Install a readily acces- sible manual shut-off valve in the gas supply line as recommended by the local utility . Check with local utility for minimum height. 6” Max. Air Gap Suitable Drain Discharge Pipe (Do Not plug or cap) 3” Minimum Drip Leg Ground Joint Union FIGU RE 3 . Gas Pressure W ARNING Explosion Hazard ?[...]

10 W ARNING • Use a new CSA approved gas supply line. • Install a shut-off valve. • Do not connect a natural gas water heater to an L.P . gas supply . • Do not connect an L.P . gas water heater to a natural gas supply . • Failure to follow these instructions can result in death, explosion, or carbon monoxide poisoning. Explosion Hazard Ga[...]

11 T ABLE 3 BTUH Input Minimum Square Feet with 8’ Ceiling T ypical Room with 8’ Ceiling 30,000 188 9 x 21 45,000 281 14 x 20 60,000 375 15 x 25 75,000 469 15 x 31 90,000 563 20 x 28 105,000 657 20 x 33 120,000 750 25 x 30 135,000 844 28 x 30 IMPORT ANT : • The area must be open and be able to provide the proper air requirements to the water [...]

12 12” Max. Permanent openings to the outside or additional rooms within the building Closet or other confined space 12” Max. FIGU RE 4 . All Air from Inside the Building When additional air is to be provided to the confined area from additional room(s) within the building, the total volume of the room(s) must be of sufficient size to properly [...]

13 FIGU RE 8 B. V ent Pipe System This water heater uses a non-direct, single-pipe vent system to remove exhaust gases created by the burning of fossil fuels. Air for combustion is taken from the immediate water heater location or is ducted in from the outside (see “Combustion Air Supply and V entilation”). This water heater must be properly ve[...]

14 Align the legs of the draft hood with the slots provided. Insert the legs and secure the draft hood to the water heater ’s top with the four screws provided as shown in Figure 9. Do not alter the draft hood in any way . If you are replacing an existing water heater , be sure to use the draft hood supplied with this water heater . V ent Pipe Si[...]

15 Piping Installation Piping, fittings, and valves should be installed according to the installation drawing (Figure 13). If the indoor installation area is subject to freezing temperatures, the water piping must be protected by insulation. The water supply pressure should not exceed 80 psi. If this occurs, a pressure reducing valve with a bypass [...]

16 Hot Water Outlet In a closed system use a thermal expansion tank Cold Water Inlet V alve Pressure Reducing V alve with Bypass Main Water Supply Cold Water Supply to Fixture Discharge line (Do Not Cap or Plug) Drain line 3/4” ID Min. Drain 1“ Min. Metal Drain Pan 1-3/4” Depth Max. Massachusetts: Install a vacuum relief in cold water line pe[...]

17 For protection against excessive pressures and temperatures, a temperature and pressure relief valve must be installed in the opening marked “T & P RELIEF V AL VE” (see Figure 15A). This valve must be design certified by a nationally recognized testing laboratory that maintains periodic inspection of the production of listed equipment or[...]

18 A diaphragm-type expansion tank suitable for potable water will normally eliminate this weeping condition. Please read and follow the manufacturer ’s instructions for the installation of such tanks. MASSACHUSETTS CODE DOES NOT ALLOW THIS TYPE OF INST ALLA TION. Must Be V ertical T o Remove Air Bubbles Domestic Hot Water Out Mixing V alve Hot W[...]

19 □ Duct wor k is the same c ross - secti onal area as the openings. V ent Pipe System Check for proper drafting at the water heater draft hood. Refer to the “Checking the Draft” section of this manual for the test procedure. If the procedure shows insufficient draft is present, please check the following. □ Draf t hood prope rly inst alle[...]

20 W ARNING Explosion Hazard Replace view port if glass is missing or damaged. Failure to do so can result in death, explosion or fire. Operating Instructions Read and understand these directions thoroughly before attempting to operate the water heater . Make sure the view port is not missing or damaged (See Figure 25). Make sure the tank is comple[...]

21 M ATCH RELIEF OPENIN G DRAFT HOOD FIGU RE 18. If the flame flutters or is blown out, combustion products are escaping from the relief opening. If this occurs, do not operate the water heater until proper adjustments or repairs are made to the vent pipe system and/or air supply requirements. Checking the Draft W ARNING Burn Hazard Do not touch ve[...]

22 Burner Flames Inspect the burner flames through the viewport and compare them to the drawings in Figure 19. A properly operating burner should produce a soft blue flame. Blue tips with yellow inner cones are satisfactory . The tips of the flame may have a slight yellow tint. The flame should not be all yellow or have a sharp blue-orange color . [...]

23 Good venting is essential for a gas fired water heater to operate properly as well as to carry away products of combustion and water vapor . It is always recommended that a suitable metal drain pan be installed under the water heater to protect the area from water damage resulting from normal condensation production, a leaking tank or piping con[...]

24 Powered Anode Operation T o protect the glass-lined water tank from corrosion through electrolysis, this water heater is equipped with a non sacrificial powered anode rod. The powered anode rod is non sacrificial and should not need to be replaced unless damaged. If the powered anode rod has been damaged then the powered anode rod should be remo[...]

25 properly . T o prevent water damage, the valve must be pro- perly connected to a discharge line which terminates at an adequate drain. Standing clear of the outlet (discharged water may be hot), slowly lift and release the lever handle on the temperature and pressure relief valve to allow the valve to operate freely and return to its closed posi[...]

26 Replacing the Flame Sense/Hot Surface igniter Assembly 1 . Remov e the manifold/ bur ner assembly . See Removing the Manifold/Burner Assembly . 2. Lift the retainer c lip strai ght up from th e back of the manifold c omponent bloc k ( using a f lat- blade screwdriver) , then remove the manifold compo nent block fr om the manifold doo r (Figure 2[...]

27 3. Insert the manifo ld/ burner as sembly into the burner compar tment making sure t hat the tip of the manifo ld tube engages in the slot of the brac ket inside the combust ion chamber (Figure 29). 4. Inspect the door gasket and mak e sure there is no f iberglass insulation bet ween the gasket and the com bus tion cham ber . 5. R e place the t [...]

28 TROUBLESHOOTING CHART PROBLEM POSSIBLE CAUSE(S) CORRECTIVE ACTION NO HOT W A TER 1 . T ransformer unplugged. 2. No power at outlet. 3. Therm ostat defect ive. 4. Air Intake Chamber F an defective. 5. Pressure Sw itch defective. 6. Gas V a lve/ Ther most at Switc h in “OFF POSITIO N ” . 1 . Plug transfo rmer bac k into 1 20 V AC. outlet. 2. R[...]

29 PROBLEM POSSIBLE CAUSE(S) CORRECTIVE ACTION COMBUSTION ODORS 1 . Insuf f ic ient secondar y air . 2. Water heater flue or vent system blocked. 3. Heater installe d in a co nf ined area. 1 . Provide ventilation to water heater . Check f lue. 2. Clean, located sourc e and cor rec t. 3. Provide fresh air ventilatio n. W A TER LEAKS 1 . Improper ly [...]

30 Please check g uidelines below. For y our safety, water heat er service shoul d be performe d only by a quali ed serv ice person. Read the GENERAL S AFE TY INFORMAT ION supplied b y the water he ater manu facturer. 1. “POW ER” Flashing Communication Er ror The system has detected a communication error between the upper and lower controls.[...]

31 6. “P-S W”, “OPEN ”, and “CLEA N SCREEN ” Flashing The air pressure switch contacts remain open longer than 5 seconds after the com bustion fan is energized. 1. Clean the sc reen on the com bustion air intake tube. Retest, if the problem persists: 2. Ensure the press ure switch sensing t ube is in good condition and securely connecte[...]

32 cont. 11. “FV-SEN SE” and “OPEN” F lashing Flammable Vapor Sensor is open 1. Check all wiring to the ammable vapor sensor. 2. Remove the connecto rs from the ammable vapor sensor and measure the res istance of t he sensor with an ohmmeter . A. If the reading taken is more than 1.7 million ohms, replace the ammab le vap or sen so[...]

33 Please Note: The control c on ti nu a ll y mo n it ors internal circuits and extern a l se ns o rs. Error codes noted abov e , an d th os e f or self-diagnostic faults c an be fo u nd on pages 30 through 32. APPLY POWER T O APPLIA NC E YES REQUEST FOR HEAT PRESENT? NO IS PRESSURE SWI TC H PROVEN OPEN WI TH IN 5 SECONDS? NO COMBUSTION FAN ON YES [...]

34 Item No. Parts Description 1 Draft Hood 2 Flue Baffle 3 Nipple (Hot) 4 Nipple (Cold) 5 Anode Rod 6 Cold W ater Inlet T ube 7 T emperature and Pressure V alve 8 Control Display 9 Air Intake Chamber 10 Gas Control V alve/Thermostat 1 1 Drain V alve 12* Natural Gas Burner 13* Hot Surface Igniter (HSI) 14* Manifold Door Assembly - Natural Gas 15* Ma[...]

35 Listed Parts Kits and Illustrations Item 1 2: Bur ner (Natural G as ) Item 1 3: Flame Sense/ Hot Sur fac e Igniter As sembly . Item 1 4: Manifo ld door assembly w hich c ontains the manifo ld tube, gask et, manifold door , manifold co mponent block with retainer c lip, and flame sense/ho t sur fac e igniter as sembly . (Natural Gas ) Item 1 5: C[...]

36 NOTES[...]

37 NOTES[...]

38 NOTES[...]

39 THIS W ARRANTY IS APPLICABLE T O THE ORIGINAL OWNER ONL Y in accordance with the warranty terms and conditions speci fi ed below . The warrantor will furnish the ORIGINAL OWNER, 1) a replacement water heater of equivalent size and current model if the glass-lined tank in this water heater leaks and, 2) a replacement part for any component part [...]

40 LIMIT A TION ON IMPLIED W ARRANTIES Implied warranties, including any warranty of merchantability imposed on the sale of this heater under state law are limited to one year duration for the heater or any of its parts. Some states do not allow limitations on how long an implied warranty lasts, so the above limitations may not apply to you. CLAIM [...]