Updated: May 20, 2021
The trend in the industry is away from "wet ring" vacuums which use water to generate vacuum (primarily due to environmental concerns as even with a re-circulator, they waste water) but many modern dry systems are also more efficient. Nonetheless, wet vacuums are still being made and there are tens of thousands of them in use. They can be very effective and quiet systems and are still popular with many users.
As the industry is trending away from wet vacuums, it can be more difficult to find qualified service techs for your wet vacuum. Bullfrog (a division of Hager Worldwide) used to have a vacuum pump re-building service but they closed their doors some time ago. If you have a wet vacuum and run into problems, what are you to do?
As it happens, wet vacuums primarily function by moving water. The primary motive force is a water pump. As with many things in the comparatively small dental industry, these pumps have other uses as well (they are not manufactured specifically for dentistry). One of the most common uses of the pumps as used on wet vacuums is swimming pools. Those who service swimming pools may well have parts and service available for your wet vacuum pump. It may sound odd, but a swimming pool repair service may be able to help you with your wet vacuum.
The next time your vacuum pump goes awry, call the pool man.