Because they are completely useless and impossible to clean.

On the Best website it is offering a replacement sugestion. Are you sure they discontinued all models?

I would have written "because they are inadequate and impractical to clean." There are commercial ceiling systems. They all depend on some grease destruction/disassociation technology to deal with the difficulty in cleaning. Here is a passage from a Halton blurb describing a disassociation scheme:

The Capture Ray™ system is installed in a plenum, which has been studied in detail using computational fluid dynamics (CFD) to ensure optimum results. The Capture Ray™ control panel is designed to operate the UV lamps only under safe conditions and to give a warning in the case of lamp failure, fan failure, other operational failure or expiration of lamp lifetime. Lifetime of one UV lamp is up to 10,000h, if system is maintained as per Halton’s Operation & Maintenance manual.

When large manufacturers discontinue a line, it is because it is not selling, and/or they’ve had a lot of returns or warranty calls. They are in business to make a profit.

I believe Broan makes the Wolf ceiling-mounted exhaust. It will be interesting to see if Wolf also discontinues it, or finds another supplier.

@anne szy - please provide a link or screen shot or any backup to your post that says " Best looks like they are discontinuing their entire line of Ceiling Vent Hoods". I agree with @bry911's comment.

Following up on what bry911 said, on my computer, I do see that some Best ceiling mount exhausts are discontinued but, on the page for the 43" CC34E6SB model, directly beneath the "Discontinued" I see the word "replacement." Clicking on that takes you to the page for the current 43" model, which is the HBC143ESS. If you are not finding that link in your device's browser, here is a link to take you directly to the current model: https://bestrangehoods.com/product/built-in/hbc143ess.

Discontinued, or current, it doesn't matter. They are inadequate for any real ventilation needs, and almost impossible to maintain properly.

^^Agree. And to elaborate on @Minardi's comment, to clean a ceiling-mounted exhaust means getting out a ladder, climbing up there, pulling down the filter, carrying it down the ladder, cleaning it, climbing back up to the ceiling while carrying it, re-installing, putting ladder away. A fall risk for you or family members. If you want your handyman or housekeeper to do it, make sure your home insurance has adequate liability coverage if they fall.

Yay! They are nothing but a scam anyway..

Ok folks… You are exaggerating a bit now. It is a pain to get out the ladder and clean the filter, which means you are probably not going to do it as often as you should. But…it is not especially dangerous.

A decent ladder is relatively safe. Much safer than a stool, for example. Statistically speaking you are much more likely to be injured walking down stairs in your home than you are getting on a ladder occasionally. Your house likely has light bulbs, smoke detector batteries, and other things that occasionally call for a ladder and no told you to avoid those things.

There is also no substantial liability issue when a handyman or housekeeper falls off a ladder that is in good working order. You have a duty to protect people from unforeseen dangers. Someone, whose job includes climbing in a ladder, being injured while climbing on a ladder, would not be a real liability issue for the homeowner.

Keep in mind that the ceiling assembly is over the cooktop, and in all cases of Ceran type cooktop surfaces, a baffle assembly or other large part dropped by accident has a very high chance of cracking the cooktop when the two meet. An impact protective covering is suggested for use during the cleaning process.

Also, this ladder concept may need some refinement depending on ceiling height and ceiling vent size. Perhaps a step ladder next to the cooktop will do. In some cases the ladder may have to straddle the island. This may call for an interior scaffold or similar configuration such as a pair of ladders with planks crossing above the cooktop.

@bry911 - the issue is that there is no need for a ladder at all if the kitchen has an exhaust hood mounted over the cooktop. A ceiling exhaust will need to be cleaned at least monthly or the filter will become clogged which impairs the hood effectiveness. As compared to a smoke alarm, for which you can buy 10-year batteries (though in my experience they last 5 years). LED bulbs need changing about every 14 years. The more often the ladder has to be used, the higher the likelihood of a fall. The reason people are statistically more likely to be injured walking down stairs than ladders is because stairs are used dozens of times a day compared to how often ladders are used in a home. But setting that aside, people procrastinate changing smoke alarm batteries, even though it can endanger their lives. What then is the likelihood of the homeowner climbing a ladder monthly or bi-monthly to clean the ceiling exhaust. It is important to convey to people who believe ceiling exhausts are a great choice what the reality will be. And that's not even talking about the ceiling exhaust's effectiveness.

M. Miller: I have the impression that you are lecturing me on the superior utility of hoods; I have addressed that topic here myriad times in the past 15 years. Nor have I failed to point out the performance limitations of ceiling systems that are not large relative to the cooking zone. So the first response by Zumi and my follow-up comment was sufficient for addressing performance. If not, a search could be recommended.

Further, it is unclear how often cleaning of inadequate ceiling systems might be needed, given their failure to fully capture and contain greasy cooking plumes. A ceiling wash might be called for more often.

I could also point out that baffled hood systems remain effective for long periods whether cleaned or not. They can become an aesthetic disaster area long before centrifugal extraction is degraded. Other schemes for ceiling venting that may be sold without embedded grease disassociation may or may not have performance issues with cleanliness.

Ultimately, the commenting community may wish to answer the OP's question as well as inject their advice. Attacking answers to the question is probably an over-reaction once deficiencies have been raised.

@kaseki my intention was not to "lecture you on the superior utility of hoods". I was responding specifically to @bry911's comment, which is why I tagged @bry911 at the start of my comment. I guess I should have copied and pasted their specific sentences from their comment that I was replying to. But if you read @bry911's comment, and then read mine you will see my comment was replying to it.

"Attacking answers to the question is probably an over-reaction once deficiencies have been raised."

Yes, exactly. This admonition applies to yourself as well.

“the issue is that there is no need for a ladder at all if the kitchen has an exhaust hood mounted over the cooktop.”

No, that is not the issue at all. The issue is that making a good point doesn’t give you license to fabricate things. There are plenty of good reasons not to get a ceiling mounted hood but that doesn’t give you the right to fabricate a legal liability for it.