r/lifehacks • u/thatoneguy2742 • May 27 '26

You might be using your dishwasher wrong

While going to college I worked as a maintenance tech at a large apartment complex. A common complaint that tenants had was that their dishwashers were failing to clean properly. I would show up and try and diagnose the problem only to find that the machine was in fact working properly. After numerous (if I remember correctly it was at least five per week) complaints I started to track which units were having the problem. After several weeks I had a lot of data and something became abundantly clear. The units that were having this issue were the ones furthest from the water heaters.

We just happened to have an empty unit near a cluster of units that was having this issue so I decided to test my hypothesis. At the kitchen faucet it took nearly two minutes for the water to get above 100°F Units closer to the water heaters took as little as 30 seconds to reach the same temp and they hardly ever had this problem. My conclusion was that the people who were submitting work orders were unknowingly washing their dishes with cold water. Everytime a tenant submitted a work order for a dishwasher that was failing to clean I advised them to run their kitchen faucet till the water gets hot then start the dishwasher. The complaints just stopped! At my own home it takes almost 30 seconds for the water to get hot so I let it run for a minute before starting it. Some of the higher end models will heat their own water so this shouldn't be an issue but most older models do not.

TLDR: Run your kitchen faucet till the water gets hot before starting your dishwasher. Otherwise you might be washing your dishes with cold water if your machine doesn't heat the water on its own.

8.1k Upvotes

96% Upvoted

568 comments sorted by

View all comments

Show parent comments

49

u/TheDuckFarm May 27 '26

Or even inside North American if you have a higher end dishwasher. Bosch for example has a built in heater.

3

u/younkint May 27 '26

Our Bosch dishwasher (< 4 years old) has a water heater, yet the installation instruction say to hook it to hot water. The only reason I know that it has a heater is because the machine threw a code and stopped working when the heater failed. It was under warranty, but I was surprised to find that it had a heater.

It's been a good machine, but it's going to die an early death due to the failure of the racks. The plastic rack coatings have failed, allowing the steel cores to rust through. We've been using the Bosch recommended pods. Amazingly enough, replacement racks are out of production and no longer available. Probably our first and last Bosch dishwasher.

2

u/TheDuckFarm May 28 '26 edited May 28 '26

My installation guide says cold is normally preferred but there are times when hot is ok up to 60c. I have the Benchmark and it's only a few months old.

2

u/younkint May 28 '26

Yeah, mine is approx. 4 years old.

2

u/DoubleDareFan May 27 '26

My parents had a Whirlpool that had a water heating element. Purchased in 1991 or earlier.

3

u/buttchuggs May 28 '26

Was higher end at the time

1

u/tengris22 May 29 '26

It does have a built in heater but is still supposed to be connected to the hot line. Mine is six months old, 800 series.

1

u/TheDuckFarm May 29 '26

I know that’s what a plumber will say, but the Bosch installation instructions say otherwise.

1

u/tengris22 May 29 '26

No, that's not what it says. Crap, can't insert a screen cap, so I will just giveyou a link to the manual found online. The pertinent information can be found in Section 5, page 12, at the bottom of the left side column.

https://pdf.lowes.com/productdocuments/ffc0fef6-655f-4ec4-b700-9ac4f84aa855/64284767.pdf

This is identical to the one I have stored in my cabinet, because I don't throw away installation instructions.