The first documented mention of the sulfur bath in Wilen dates back to 1605. However, its origins are likely much older. In 1687, the then-owner was asked by the authorities, with the promise of a financial contribution, to build a dwelling over the sulfur bath. In 1819, a new bathhouse was constructed, and the spring was newly tapped. This marked the final development of Wilerbad into a spa facility with space for around 20 guests, who slept on leaf sacks. For treatment, there were four bathing cabins on the first floor and several "bathing boxes" in the basement available. The spa house was accessed by a narrow, bumpy pack trail. Guests had to make their way on foot or were carried in sedan chairs.

In 1843, Johann Kaspar Jakober, a practicing doctor, took over the spa and continued to run it until 1881. However, despite the expansion of the access road, with diminishing success. A few years after his death, it was eventually the daughter who allowed the spa to deteriorate into an inn with a rather dubious reputation. Thus, the church council, which was responsible for issuing business licenses at that time, decreed that card games were forbidden at the Wilerbad and only cider and Bränz (brandy) could be served.

It followed a checkered history with ups and downs until 1927 when Moritz Rogger took over the spa house, renewed it from the ground up, and gradually expanded it into a hotel operation. This experienced its greatest bloom after the Second World War. Weddings at Wilerbad were particularly popular, and the military also made a not insignificant contribution to economic success. However, the sulfur spring dried up and was forgotten.

In view of a necessary complete renovation, the Zug-based company Peikert took over the Wilerbad in 1987 and developed a concept for a modern hotel facility focused on seminars. The opening of today's Seehotel Wilerbad was celebrated in spring 1995, and since 1996 the Wilerbad has been privately owned by the Rainer Peikert family. With the daughter Simona Segantini-Peikert, the next generation is already committed to a successful future for this traditional hotel business and historic bath.

Since spring 2013, people have been bathing, relaxing, and recharging at Wilerbad again. The attractive spa thus connects to the history of the place but opens up a completely different world of revitalization and relaxation. In a natural, light-filled architecture with wonderful views and outlooks, hotel guests and day spa visitors discover a wellness and fitness offering for all five senses, beautifully uniting Eastern and Western traditions.