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  4. GPVL-50
  5. Service Handbook

A.O. Smith GPVL-50 Service Handbook

Manual is about: RESIDENTIAL GAS WATER HEATERS POWER VENTED GAS MODELS WITH HOT SURFACE IGNITION NOT FOR USE IN MANUFACTURED (MOBILE) HOMES

Summary of GPVL-50

  • Page 1

    Service handbook 1206 322153-000 rev. 00 power vented gas models with hot surface ignition not for use in manufactured (mobile) homes residential gas water heaters table of contents note: references to the manual refer to the “installation and operating manual”. General information 2 checking the ga...

  • Page 2: General Information

    2 draw ef fi ciency is the quantity of hot water available to the consumer before the outlet water temperature decreases by 25f° (14c°). A 40 gallon water heater will typically provide 70% (28 gallons) of this “usable” hot water (60% is the minimum). The burner or elements are allowed to operate dur...

  • Page 3

    3 gas pressure checks are done with fl owing gas using a gas pressure manometer capable of reading pressure in inches of water column. Supply gas pressure checks are measured before the gas control valve and as close to the water heater as possible. Manifold (main burner) gas pressure is measured at...

  • Page 4: Leakage Checkpoints

    4 leakage checkpoints a. Water at the blower assembly is water vapor which has condensed out of the combustion products. This is caused by a problem in the vent or blockage in the drain coupling. B. Condensation may be seen on pipes in humid weather or pipe connections may be leaking. C. The anode r...

  • Page 5: Temperature Adjustment

    5 safety due to the nature of the typical gas water heater, the water temperature in certain situations may vary up to 30f° (16c°) higher or lower at the point of use such as bathtubs, showers, sink, etc. Hot water can scald: water heaters are intended to produce hot water. Water heated to a tempera...

  • Page 6

    6 anode rod important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: ratchet with 1-1/16” socket pliers te fl on ® tape or an approved p...

  • Page 7

    7 dip tube removal/replacement dip tube important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: 18” pipe wrench piping and soldering eq...

  • Page 8

    8 inner door/manifold/burner assembly important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: 3/4” open-end wrench phillips head screwd...

  • Page 9

    9 re-installing inner door/manifold/burner assembly insert the manifold/burner assembly in the burner chamber compartment, making sure that the tip of burner manifold tab engages in the proper slot of the bracket (see figure 8). Important: • the tip end of the burner manifold must be placed in the u...

  • Page 10

    10 flame sensor and/or hot surface igniter important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: 3/4” open-end wrench phillips head s...

  • Page 11

    11 reconnect the manifold tube to the gas control valve/ thermostat ( note: do not apply any thread sealant at this connection). To prevent any cross threading the manifold tube should be started by hand (turn clockwise for natural gas, counter-clockwise for l.P.). Upon tightening with the fi ngers ...

  • Page 12

    12 burner important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: 3/4” open-end wrench phillips head screwdriver ratchet with 1/4” sock...

  • Page 13

    13 reconnect all the electrical connections to the bottom of the gas control valve/thermostat, gently pushing each connector up until it snaps into place (see figures 10 & 15). Reconnect the electrical power to the water heater in the wall outlet and turn the gas supply back “on” to the gas control ...

  • Page 14

    14 burner orifice important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: 3/4” open-end wrench phillips head screwdriver ratchet with 1...

  • Page 15

    15 do not operate the water heater if the door gasket does not create a seal between manifold door and combustion chamber. Reconnect the manifold tube to the gas control valve/ thermostat ( note: do not apply any thread sealant at this connection). To prevent any cross threading the manifold tube sh...

  • Page 16: Door Gasket Replacement

    16 door gasket important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: 3/4” open-end wrench 3/4” scraper ratchet with 1/4” socket or 1/...

  • Page 17

    17 replacing the door gasket. Remove the paper cover on the new door gasket. This will expose the gasket adhesive. Position the gasket on the freshly cleaned door surface so that the adhesive fi rmly holds the gasket to the door. Smooth the gasket to avoid creases. 1. 2. 3. Re-installing inner door/...

  • Page 18

    18 electronic control module important: do not remove the entire gas control assembly from the water heater. Important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed servic...

  • Page 19

    19 tabs disconnect temperature sensor cable here electronic control module threaded control fitting (do not remove from water heater) figure 23.

  • Page 20

    20 valve module important: do not remove the entire gas control assembly from the water heater. Important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician....

  • Page 21: Temperature Sensor And

    21 temperature sensor and cable important: do not remove the entire gas control assembly from the water heater. Important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed ser...

  • Page 22

    22 gas control valve important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: 3/4” open-end wrench short length of 1/2” threaded pipe pi...

  • Page 23

    23 electrical connections manifold tube nut hex head screws note: outer door and insulation not shown for clarity. Figure 26 threaded pipe “handle” figure 27.

  • Page 24: Blower Removal/replacement

    24 blower important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: ratchet with 5/16” socket or 5/16” nutdriver ratchet with 1/4” socket...

  • Page 25: Rotating The Blower

    25 blower exhaust direction important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: ratchet with 11/32” socket or 11/32” nutdriver the ...

  • Page 26

    26 pressure switch important: use only factory authorized replacement parts. If you lack the necessary skills to properly perform the installation, you should not proceed, but get help from a quali fi ed service technician. Tools required: phillips head screwdriver ratchet with 1/4” socket or 1/4” n...

  • Page 27: Fv Sensor

    27 flammable vapor sensor when using a gas fi red water heater there is a risk of fl ammable vapors entering the combustion chamber, being ignited by the burner fl ame and causing a fl ashback. In order to detect such fl ammable vapors before they enter the combustion chamber, this water heater is e...

  • Page 28

    28 follow procedure outlined in “removing inner door/ manifold/burner assembly”. Use a vacuum cleaner/shop vac to remove all loose debris in the combustion chamber. Reassemble following the procedure under “installing inner door/manifold/burner assembly”. 1. 2. 3. Cleaning the combustion chamber.

  • Page 29: Cleaning The Blower

    29 blower in dusty and contaminated air conditions, the interior of the blower and the blower wheel may require periodic cleaning. This is often indicated by nuisance failures of the air pressure switch or the high limit temperature control. A collection of dust or debris on the rear blower air inta...

  • Page 30: Technical Bulletins

    30 water hammer general water hammer is the destructive force, pounding noise and vibration in a piping system when water fl owing through a pipeline is stopped abruptly. When water hammer occurs, a high intensity pressure wave travels back through the piping system until it reaches a point of some ...

  • Page 31

    31 condensation symptoms the water heater appears to be releasing water while the main burner is on or water is found surrounding the heater shortly after the water heater has been used. This section explains why fl ue gases condense and how you can differentiate between condensation and leaking. Ca...

  • Page 32

    32 smelly water symptoms rusty, brown, black, or yellow water appearing in the hot water. Causes the most common cause of “smelly water” is a non-toxic sulfate reducing bacteria, scienti fi cally termed divibrio sulfurcans. This bacteria often enters the water system through construction or a break ...

  • Page 33

    33 chlorination procedure causes the chlorination procedure is used to eliminate various bacteria that accumulate and grow in water heaters. These bacteria often cause odorous or discolored water conditions. Treatment the simplest treatment available is the shock-chlorination of the system. This is ...

  • Page 34

    34 thermal expansion symptoms • effects are only noticeable after hot water use followed by periods of no water use. • relief valve drips during any recovery cycle when no hot or cold water is used. • hot water pipes creak while water heater is recovering and all valves are closed. • tanks or other ...

  • Page 35

    35 leaking temperature and pressure relief valve symptoms • water seeping around the relief valve tank connection. • leakage at the threaded portion of the relief valve connection. • intermittent weeping and/or dribbling from the relief valve. • large volume of hot water sporadically discharged from...

  • Page 36: Troubleshoting Chart

    36 problem possible cause(s) corrective action burner flame too high insuf fi cient secondary air ori fi ce too large 1. 2. Provide ventilation to water heater replace with correct ori fi ce 1. 2. Flame burns at orifice low gas pressure d e f e c t i v e g a s c o n t r o l (thermostat) 1. 2. Check ...

  • Page 37

    37 problem possible cause(s) corrective action smoking and carbon formation insuf fi cient secondary air low gas pressure ori fi ce too large flue clogged d e f e c t i v e g a s c o n t r o l (thermostat) heater installed in a con fi ned area 1. 2. 3. 4. 5. 6. Provide ventilation to water heater. C...

  • Page 38

    38 gas control led status codes led flash sequence control status short fl ash once every four seconds idle (no call for heat, no fault conditions) “heartbeat”, alternates bright/dim call for heat (no fault conditions) one flash, three second pause low flame signal (control continues to operate) two...

  • Page 39

    39 this page intentionally left blank. May be used for notes or to record other installation information..