Reliance
Gas Water Heater

Model #640HBDS Official Reliance water heater

Here are the diagrams and repair parts for Reliance 640HBDS water heater, as well as links to manuals and error code tables, if available.

There are a couple of ways to find the part or diagram you need:

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For DIY troubleshooting advice and repair guides, visit our repair help section.

Error Codes

    Showing 10 of 14 parts

    Water Heater Magnesium Anode Rod#8

    Water heater Diagram

    In Stock
    $35.03
    Vent Assembly#5

    Water heater Diagram

    Vent assembly

    Part #9006538005
    In Stock
    $452.49
    Water Heater Anode Rod#8B

    Water heater Diagram

    Water heater anode rod

    Part #9006299005
    In Stock
    $54.59 | 
    8% OFF 
    Phone Price: $59.59
    Anode Mg#8A

    Water heater Diagram

    Anode mg

    Part #9003938005
    Back Order
    $52.49
    Drain Valve#4

    Water heater Diagram

    Drain valve

    Part #9003906015
    Replaced by #9009086015
    ?
    Manufacturer substitution
    This part replaces 9003906015. Substitute parts can look different from the original.
    In Stock
    $19.49
    End Vent#7

    Water heater Diagram

    End vent

    Part #9006540005

    The manufacturer no longer makes this part, and there's no substitute part

    Door Burner#1

    Water heater Diagram

    Door burner

    Part #9006527005

    The manufacturer no longer makes this part, and there's no substitute part

    Trim Plate#12

    Water heater Diagram

    Trim plate

    Part #9006701005

    The manufacturer no longer makes this part, and there's no substitute part

    Gas Valve#3

    Water heater Diagram

    Gas valve

    Part #9006537005

    The manufacturer no longer makes this part, and there's no substitute part

    Heat Trap#10

    Water heater Diagram

    Heat trap

    Part #9003915015

    The manufacturer no longer makes this part, and there's no substitute part

    Symptoms common to all water heaters

    Choose a symptom to see related water heater repairs.

    Main causes: lack of power, no gas supply, thermostat limit switch tripped, bad element, bad thermostat, gas valve failure, bad thermocouple
    Main causes: water supply needs chlorine treatment, anode rod too reactive
    Main causes: thermostats need adjustment, water heater capacity too low, bad heating element, thermostat failure, excessive tank sediment
    Main causes: thermostat temperature set too high, thermostats need adjustment, faulty thermostat, shorted heating element
    Main causes: faulty pressure relief valve, water is overheating
    Main causes: broken heating element, thermostat failure, excessive tank sediment, tank size too small, burner valve assembly failure
    Main causes: loose water pipe fittings, leaky drain valve, bad temperature-pressure relief valve, leaky heating element, cracked tank

    Articles and videos common to all water heaters

    Use the advice and tips in these articles and videos to get the most out of your water heater.

    October 24, 2022

    Easy DIY appliance repairs that anyone can do

    By Lyle Weischwill

    Get advice on simple DIY fixes for appliances that you can safely do on your own.

    August 18, 2021

    Wiring schematic symbols explained video

    By Lyle Weischwill

    Learn some of the most common symbols found in a wiring diagram and what they mean.

    April 10, 2020

    Cleaning your appliances after a drinking water advisory

    By Julie Riebe

    Find out how to clean and flush household appliances once a boil water advisory is lifted.