Today, I washed my hands at the kitchen sink while making lunch, and was unexpectedly chastised by my partner because she had just started the dishwasher. Apparently, she has recently come across something that has convinced her that running the hot water in your sink means the water that enters your dishwasher will be hotter (checks out), and thus the dishes will be cleaner. I tried searching startpage to see if this is real, but I couldn’t make it through even one llm-slop-ticle about it before my eyes rolled back into my head, so here I am asking y’all: chat, is this real? Doesn’t my dishwasher have a heating element? Is there any meaningful difference between heating the water with a hot water heater vs a dishwasher, other than I can’t use my sink while the dishwasher is filling and I have to pour a bunch of cool water down the drain?
It has nothing to do with that. It is about the electrical system in the US not being able to supply water heaters in dishwashers and washing machines. Also the system you are describing is certainly a UK-centric one.
That is a myth arising from US typical residential circuit standard being 20A @ 120V, or 2400W.
Major appliances are not limited to this typical standard. US/Canada have code for and commonly install dedicated 30A@120V, (commonly used for large through-window air conditioners) as well as 240V circuits rated from 20A to 80A. The North American electrical system typically provides 200A @ 240V to the residence. That’s sufficient for heating hot tubs and in-ground pools.
No, the decision to use hot water instead of cold water arises primarily from plumbing factors, not electrical.
It’s because I have never seen a dishwasher in the US designed for a high current circuit.
The standard is a single dedicated 15amp circuit for the dishwasher, because the standard dishwasher is designed to use the house hot water, so doesn’t need a larger circuit for a water heat cycle at the start.
Since US homes have a built-in, stable hot water supply, why would you build further pre-heat into a dishwasher?
It has fuck all to do with the water supply,
Right. But, if they did make a 5000W dishwasher, it would not be difficult to power it in the US. Even though typical NEMA 5-15 and 5-20 outlets can only handle 1800/2400W, US electric code provides for 50A@120V, 20A@240V, and much, much larger circuits for ranges, water heaters, hot tubs, pools, arc welders, air compressors, etc. There is no electrical limitation preventing adoption of cold-water dishwashers.