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Thermo-King
Water Heater

Model # 5-40-20RT8-2 Official Thermo-King electric water heater

Here are the diagrams and repair parts for Official Thermo-King 5-40-20RT8-2 electric 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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  • In the search box below, enter all or part of the part number or the part’s name.

Not all parts are shown on the diagrams—those parts are labeled NI, for “not illustrated”.

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Error Codes

Model diagram and schematic

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ALL PARTS
Showing 10 of 23 parts  |
Thermostat 9000510
#7

Round electric diagram

Thermostat

Part #9000510

Replaced by #9001954015

?
Manufacturer substitution
This part replaces 9000510. Substitute parts can look different from the original.
BEST SELLER
$28.93 | 
17% OFF Phone Price : $34.93
In Stock
Water Heater Heating Element Gasket 9000308
#4

Round electric diagram

Water heater heating element gasket

Part #9000308

Replaced by #9000308005

?
Manufacturer substitution
This part replaces 9000308. Substitute parts can look different from the original.
$30.62 | 
16% OFF Phone Price : $36.62
In Stock
Access Cover 9001764
#19

Round electric diagram

Access cover

Part #9001764

This item is not returnable
$5.99
In Stock
Access 9000927
#21

Round electric diagram

Access

Part #9000927

This item is not returnable
$4.99
In Stock
Access Bolt 9000928
#20

Round electric diagram

Access bolt

Part #9000928

This item is not returnable
$4.99
In Stock
Anode Rod 9001828
#15

Round electric diagram

Anode rod

Part #9001828

Replaced by #100109594

?
Manufacturer substitution
This part replaces 9001828. Substitute parts can look different from the original.
$55.56
In Stock
Drip Pan 9000741
#23

Round electric diagram

Drip pan

Part #9000741

Replaced by #9002846

?
Manufacturer substitution
This part replaces 9000741. Substitute parts can look different from the original.
$20.99
In Stock
Anode Rod 9000705
#2

Round electric diagram

Anode rod

Part #9000705

Replaced by #100300397

?
Manufacturer substitution
This part replaces 9000705. Substitute parts can look different from the original.
$55.38 | 
10% OFF Phone Price : $61.38
In Stock
Water Heater Thermostat Bracket (replaces 0110238, 0110238-01, 0110322, 9000309015) 9000309
#12

Round electric diagram

Water heater thermostat bracket (replaces 0110238, 0110238-01, 0110322, 9000309015)

Part #9000309

Replaced by #100108380

?
Manufacturer substitution
This part replaces 9000309. Substitute parts can look different from the original.
$27.78
In Stock
Drain 9000058
#13

Round electric diagram

Drain

Part #9000058

Replaced by #100108269

?
Manufacturer substitution
This part replaces 9000058. Substitute parts can look different from the original.
$18.57
In Stock

Most common symptoms to help you fix your water heaters

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Why isn't my water heater heating my water?

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Why isn't my water heater making the water hot enough?

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Repair guides for electric water heaters

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How to replace a water heater element

How to replace a water heater element

If your water heater runs out of hot water quickly and one of the two heating elements has failed, replace the element f…

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Repair difficulty
Time required
 30 minutes or less
How to replace an electric water heater anode rod

How to replace an electric water heater anode rod

If your hot water begins to smell like rotten eggs, replace the anode rod with a zinc-aluminum anode rod following the i…

Read more
Repair difficulty
Time required
 15 minutes or less
How to replace an electric water heater thermostat

How to replace an electric water heater thermostat

If the water temperature fluctuates or you don't get enough hot water, follow these instructions to replace your water h…

Read more
Repair difficulty
Time required
 30 minutes or less

Effective articles & videos to help repair your water heaters

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How to read a wiring schematic video

How to read a wiring schematic video

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Easy DIY water heater repairs

Easy DIY water heater repairs

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Water heater common questions

Water heater common questions

These common questions and answers can help you make the most of your water heater.…

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