Rheem
Gas Water Heater

Model # 21V40T Official Rheem 40-gallon mobile home gas water heater

Here are the diagrams and repair parts for Official Rheem 21V40T 40-gallon mobile home gas water heater, as well as links to manuals and error code tables, if available.

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Model diagram and schematic

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Showing 10 of 13 parts  |

Burner AP-8980-C
#5A

Thermostat and burner diagram

Burner

Part #AP-8980-C

Replaced by #SP8980C

?
Manufacturer substitution
This part replaces AP-8980-C. Substitute parts can look different from the original.
In Stock
Burner AP-8980-B
#5

Thermostat and burner diagram

Burner

Part #AP-8980-B

Replaced by #SP8980C

?
Manufacturer substitution
This part replaces AP-8980-B. Substitute parts can look different from the original.
In Stock
Tube AP-8964-C
#2

Thermostat and burner diagram

Tube

Part #AP-8964-C

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

Orifice, Pilot Burner (lp Gas) (red) PA-8392-D
#8A

Thermostat and burner diagram

Orifice, pilot burner (lp gas) (red)

Part #PA-8392-D

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

Orifice AP-6234-C
#7

Thermostat and burner diagram

Orifice

Part #AP-6234-C

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

Thermostat AP-9051-B
#1

Thermostat and burner diagram

Thermostat

Part #AP-9051-B

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

Thermocouple AP-6379-E
#6

Thermostat and burner diagram

Thermocouple

Part #AP-6379-E

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

Orifice, Burner (lp Gas) (red) AP-6234-B
#7A

Thermostat and burner diagram

Orifice, burner (lp gas) (red)

Part #AP-6234-B

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

Tube AS-35137-D
#4

Thermostat and burner diagram

Tube

Part #AS-35137-D

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

Orifice, Pilot Burner (natural Gas) AP-8392-B
#8

Thermostat and burner diagram

Orifice, pilot burner (natural gas)

Part #AP-8392-B

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

Most common symptoms to help you fix your 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 failu…

Main causes: thermostats need adjustment, water heater capacity too low, bad heating element, thermostat failure, excess…

Main causes: loose water pipe fittings, leaky drain valve, bad temperature-pressure relief valve, leaky heating element,…

Main causes: water supply needs chlorine treatment, anode rod too reactive…

Main causes: broken heating element, thermostat failure, excessive tank sediment, tank size too small, burner valve asse…

Main causes: thermostat temperature set too high, thermostats need adjustment, faulty thermostat, shorted heating elemen…

Main causes: faulty pressure relief valve, water is overheating…

Effective articles & videos to help repair your water heaters

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

Wiring schematic symbols explained video

Wiring schematic symbols explained video

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

Using a wiring schematic to trace a current video

Using a wiring schematic to trace a current video

Find out what’s wrong with your appliance by following a circuit.…

Easy DIY water heater repairs

Easy DIY water heater repairs

Read about some water heater repairs that you can easily do yourself.…