Can’t find your part?   Contact us:
+1-309-603-4777
Sears Parts Direct
Orders

  • Keep track of the models you own in your profile

    Sign in or Register to view or add models

Schedule a repair
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:

  • Click a diagram to see the parts shown on that diagram.
  • 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”.

We encourage you to save the model to your profile, so it’s easy to access parts and manuals for your appliance whenever you log in.

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

Error Codes

Model diagram and schematic

SEARCH WITHIN THIS MODEL

?

This is the number corresponding to the part on the diagram / schematic

Search
ALL PARTS
Showing 10 of 23 parts  |
Thermostat 9000507
#11

Round electric diagram

Thermostat

Part #9000507

Replaced by #9000507015

?
Manufacturer substitution
This part replaces 9000507. Substitute parts can look different from the original.
BEST SELLER
$32.20 | 
16% OFF Phone Price : $38.20
In Stock
Thermostat 9000509
#9A

Round electric diagram

Thermostat

Part #9000509

Replaced by #9000509015

?
Manufacturer substitution
This part replaces 9000509. Substitute parts can look different from the original.
BEST SELLER
$33.44 | 
15% OFF Phone Price : $39.44
In Stock
Thermostat 9000508
#9

Round electric diagram

Thermostat

Part #9000508

Replaced by #9000509015

?
Manufacturer substitution
This part replaces 9000508. Substitute parts can look different from the original.
BEST SELLER
$33.44 | 
15% OFF Phone Price : $39.44
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 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
Access Cover 9001764
#19

Round electric diagram

Access cover

Part #9001764

This item is not returnable
$5.99
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
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
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.
$28.09 | 
18% OFF Phone Price : $34.09
In Stock

Most common symptoms to help you fix your water heaters

Choose a symptom to see related water heater repairs.

View all

Why isn't my water heater heating my water?

Main causes: lack of power, no gas supply, thermostat limit switch tripped, bad element, bad thermostat, gas valve failu…

Read more

Why is there water in my water heater's drain pan?

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

Read more

Why does my hot water smell like rotten eggs?

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

Read more

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

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

Read more

Why is my water heater's pressure relief valve dripping water?

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

Read more

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

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

Read more

Why is my water heater making the water too hot?

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

Read more

Repair guides for electric water heaters

View all
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…

Read more
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

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

View all
How to read a wiring schematic video

How to read a wiring schematic video

Learn how to decipher symbols so you can buy the right part for your problem.…

Read more
Easy DIY water heater repairs

Easy DIY water heater repairs

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

Read more
Water heater common questions

Water heater common questions

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

Read more

Parts & More