The vent on your Bosch is connected to a tube that first runs up the side of the d/w and then down to the base. The air in the tube condenses and the moisture runs back into the tub. Any remaining moisture (very little if any)will vent to the enclosed base at the bottom of the d/w..
The reason your countertop gets hot is because the Bosch dishwasher can heat it's wash and final rinse to over 160ºF.

Fascinating. I'd be interested in knowing more about this. I've seen these vent tubes on the side of DW, and no appliance salesperson can ever explain anything about it. Also, when I have called the manufacturers, I get a different explanation from the one in the above post.

Since the tube is facing downwards after going upwards for about ten inches, I think some condensed water would run downwards too. Nobody can make water run uphill. Then, if water is indeed condensing, and running out, I guess it has no /choice but to evaporate later.

How much steam (or condensate) is involved here? Has anyone viewing this thread ever seen the steam coming into the tube while their DW is operating?

We have had a Thermador/Bosch Emerald dishwasher for two years. Installed by our builder in our new home. Our Quartz countertop has cracked TWICE in the same spot. Our builder passed away and now we are stuck replacing our expensive countertop on our own tab. Hesitant to replace and it will crack again. We have talked to the installers, the Quartz manufactures and others. No one can help! We feel steam and heat especially during the rinse cycles. Should we vent the steam under our sink? Any suggestions would be great!

Get rid of your Bosch DW. Our delaminates a cabinet on the side.

I am having the same problem - what model do you have? I am wondering if the only solution is a new dishwasher

the higher end Miele have a drying plus feature that opens the door . door doesn't open until the steam in the DW gets below a safe temp - I think 150 or so

when ours opens there is no steam at all

I have a 3 year old Bosch dishwasher and I hate it because the venting is totally insufficient. Everything, especially plastic, was always wet even hours after the cycle finished. I solved the problem by jarring the door open a couple of inches using a wooden spoon as soon as it‘s done. Within 30 minutes I can then empty the dishwasher and everything is 99% dried. I also hate that the cycle Is almost 2.5 hours and there’s no heat element option.

Good discussion on the function of the air-gap/steam vent which is on the side of the Bosch machine. During operation steam and/or water vapor comes out from that vent INSIDE the cabinet. Over the course of 3 years it has rotted a hole through the cabinet wall into the kitchen sink drain area. Why Bosch thinks this is OK to vent water vapor into the cabinet is beyond my comprehension. The Bosch technician said the machine is functioning as intended and he has seen this kind of problem before. I will replace the D/W with a brand that vents through the front - It will not be a Bosch since all of them vent to the side. If you own a Bosch I'd suggest you pull out your machine and look for moisture/mold damage inside your cabinet.

@HU-466986825 the house we rented had a Kitchenaid dishwasher and it did the same thing to the left side cabinet.

I'd suggest everyone pull their dishwasher out once and see what is going on. If they are able to determine if the steam vent is on the front or side then their follow-up course of action may be adjusted. Unfortunately, there are no front-vent Bosch designs and I would not buy a side vent design. Don't be fooled by the professional looking appliance articles praising Bosch "german engineering". No one in their right mind designs a steam vent into the cabinet interior.

Ann Marks, I believe KA has the vent on the edge of the door which usually isn't fully inside the cavity. Bosch has the vent on the sidewall of the tub, fully inside the cabinetry cavity.

@dadoes Maybe they changed it?? This was in a rental we stayed at in 2016 and I have no idea how old the dishwasher was at that point. I believe the dishwasher was a Kitchenaid Architect series. The left side cabinet wall next to dishwasher was a mess and it clearly looked like heat and water damage.

I currently have a Bosch 800 series dishwasher and we have been in this house 7 years. I just went and checked the cabinet walls next to the dishwasher and thankfully they are both fine.

Ann Marks, Did you check inside the cabinet where the machine is installed, or just next to it on the exterior of the enclosure? I'd suggest you pull it out at least as far as needed to see inside the cabinet. The veneer appeared fine on the outside for mine (under the sink), but behind it the particle board was gone where the vent was steaming. This Bosch says, "Silence Plus" on the control panel but no series number. It is about 4 years old.

I'm pretty steamed-up about this, but Bosch is not cooperating.

HU-466986825 I didn't pull out the dishwasher. I just looked at the cabinet walls outside. Not keen on pulling the whole dishwasher out.

I hear ya. But it's not that hard. I'm afraid I might have put a burr under your saddle now. Keep me posted if you change your mind.

Dishwashers may also have an air gap on the water inlet/fill flume, which is usually on the (left) sidewall of the tub. A slight-bit of moisure may emanate from it in some instances/conditions.