How To Test A Dishwasher

There are times when your dishwasher will start to behave funny due to some faulty part, an unclean dishwasher, faulty connections, clogs, etc.
Any of these issues will result in you needing to check your appliance to ensure if it needs to be cleaned, tweaked, repaired, or replaced.
Most of the time, when the issues are trivial, a light intervention fixes your dishwasher without you having to dismantle the appliance entirely, remove it, make major repairs, or replace any parts.
Hence, in order to ensure the extensiveness of the issue, you need to know how to test a dishwasher properly before proceeding to make any big changes; which we are about to guide you through it all!

Your dishwasher is composed of several components which may start to malfunction over time. in such cases, in order to determine whether you need a replacement or repair, you need to test out their functionality.
Today, we are about to discuss some of the components’ testing methods. For almost every type of testing, the primary item you’ll need is basically a multimeter or similar device.

1.How To Test A Dishwasher Heating Element

the heating element is what basically heats up the air in the dishwasher after a wash cycle to dry up the dishes. A faulty one needs to be repaired or replaced as soon as possible as or else, you’d end up receiving wet dishes.
As usual, the first step of proceeding to test or fix your appliance is to turn it off and disconnect its power supply.
Find the heating element inside the dishwasher. It may either be exposed or covered. If covered, take out the dish racks to access it and take off the covering.
Check and take a mental note of where the heating element’s two terminals go down through the tub’s base.
It’s time to locate and access the wiring of your dishwasher’s heating element. Find the lower kickplate panel of your dishwasher and unscrew the screws to remove it.
Now search the spot where the heating element’s terminal wires have extended from the dishwasher bottom.
Label both these extended terminals so that they can be correctly reconnected once you’re done.
A slip-on connector connects each of these terminals to their respective wires. Gently slide off the connector to disconnect the wire connection. Hold the connectors to pull them off, not the wires.
Now connect the probes of your multimeter device to each of the terminals of the heating element with the meter at the Ohm/resistance setting.
You are ought to find a reading between zero to infinite Ohms. The reading may also be within a given range as mentioned in your device’s tech sheet which will vary from model to model.
If the multimeter needle doesn’t move or it shows a reading too far away from the mentioned range, your heating element is in need of a replacement.

2.How To Test A Dishwasher Thermostat

The thermostat is responsible for regulating the dishwasher temperature that keeps it from overheating. It shuts off the heating element usually at around 207⁰F.
But when there is a defect, the thermostat gets triggered at a lower temperature, resulting in the heating element not heating up enough, resulting in your dishes not drying properly.
Follow the same or similar steps as above until you have access to the interior of the tub base of your dishwasher base.
Confirm that there is no electrical connection with your multimeter on the wiring under the tub of your dishwasher.
Locate the thermostat which looks like either one or two pieces of silver circular disks the has two wires attached. This or these are your dishwasher’s thermostats.
Gently remove the wires off the thermostat’s terminals.
Calibrate or set your multimeter to the appropriate ohm setting, preferably the RX1 setting for easier readings of low-resistance components such as your thermostat.
Connect the multimeter to the thermostat terminals and check the reading to determine its functionality in the same way as you tested the heating element.
Replace the thermostat if necessary, reassemble all the components and run a test batch of dishes on a wash cycle to confirm the dishwasher functionality.

3.Testing The Dishwasher Timer

The timer assembly of the dishwasher is responsible for regulating the length of the wash cycles, allowing power to be directed to all the specific components for that duration of time.
Sometimes, it is wrongly diagnosed to be a timer issue when the dishwasher stops running properly until the cycle is over when it’s actually some other issue. Hence, you need to properly test the timer to ensure if it’s really the timer that’s gone bananas!
The dishwasher’s timer assembly is usually situated in either its control panel that you’ll find in the upper region of the door, or at the bottom of your dishwasher tub. Access it by unscrewing all the screws after you have properly turned off your device’s power connection.
You’ll notice a couple of wires that are extending from the housing of the round motor. Follow them to navigate to the connectors.
After taking a mental note of which wire goes where to facilitate correct reattachment, remove the wires by holding the connectors with a pair of needle-nose pliers.
With your multimeter or ohm-meter at the x1000 configuration, connect it to the terminals of the timer.
Usually, a range of 2000-3500 ohms is considered optimum for most dishwashers. Check the range with your dishwasher model’s owner manual or on one of its service areas to confirm.
If you notice the reading to deviate considerably from the optimum range, you are in need of replacing the timer motor or the entire timer assembly.

4.Testing The Dishwasher Water Level Switch

This switch allows power to pass from the timer of your dishwasher to both the temperature button and the water inlet valve when the dishwasher keeps filling up during your wash cycle.
Based on the setting you have chosen according to the size of your dishload, this water level switch works accordingly, stopping the water flow as soon as the desired water level has reached. A faulty water level switch will result in overfilling or underfilling your dishwasher, resulting in flooding or ineffective dishwash.
After powering off your dishwasher, locate the water level switch after unscrewing the necessary parts as per the owner’s manual of your dishwasher. This switch’s tube is a rubber tube that you’ll notice running from the switch to below the dishwasher tub’s side.
Remove the fittings at both ends of the tube by loosening its clamps.
Check the tube’s ends for dirt, debris, clogs, etc., and clean them off.
Check for any holes or damages on the tube and replace if necessary.
Find the terminals of the switch and disconnect its wires.
Configure your multimeter at Ohms x1 setting
You’ll find a total of three terminals of the switch. Connect your multimeter to a pair of terminals until you have tested all three by switching among the terminals in pairs. For example, terminal 1 and 2, 2 and 3, and 1 and 3.
Check the readings for continuity. One of them should have it, the other two should not if the water level switch is not faulty.
Reconnect the tube and test the terminals in pairs again while blowing air via the tube gently at a constant pressure every time.
This time, the results of a good switch would be in reverse; meaning that the two pairs that didn’t show continuity before will now show it, and the one that showed continuity previously will not.
Make replacements as needed and reassemble the device to run a test wash cycle to check if the water level switch is functioning properly.

5.Testing The Dishwasher Drain Pump

The drain pump is the pump that basically deviates the water flow via the drainpipe with the help of the rotating impellers in its assembly.
A faulty drain pump means water won’t drain effectively, will accumulate at the bottom of the dishwasher, cause leaks, etc. Your dishwasher may not even start up properly due to a damaged drain pump. Hence, you need to ensure its functionality by testing it with a multimeter similarly to check if a replacement is needed or if the issue lies somewhere else.
Locate the drain pump by first running a short wash cycle. Use the owner manual to help as well.
Disconnect the electrical supply from the dishwasher and disassemble it as needed to access the interior.
Remove the connectors of the anti-flood switch.
Find the drain pump inside at the dishwasher base and disconnect the wires connected to them.
With your multimeter configured in ohms, connect it to the drain pump terminals to get a reading.
Match the reading with resistance range on the tech sheet of your dishwasher models to see if it falls within the range or not.
If not, you need to replace the drain pump.
Take apart the drain pump assembly to manually test if the drain pump impeller rotates smoothly.
Reassemble after making necessary replacements and run a test wash cycle to confirm that the water is draining properly.

Conclusion

So today, we were all about how to test a dishwasher properly in order to diagnose the issue properly when your dishwasher starts acting up.
We discussed some of the most common components that need to be tested as they are more likely to get damaged than most parts.
The main idea is basically the same- disconnecting your dishwasher from the power source, dismantling it to reach the correct component, testing with a multimeter device, and making replacements if the meter readings don’t match the specified range.
Hence, whether it’s testing any of the components we discussed today, or some other one, testing them out will hopefully no longer be an intimidating task!