Florian Wacha

Review of Zehnder GmbH

So far we have had only bad experiences with the Z...

So far we have had only bad experiences with the Zehnder company. In February 2018 we moved into our house. A Zehnder ComfortAir Q450 was installed. The ventilation system never had full power until March 2020 and was getting weaker and weaker. At the end we still had max. 170 m3 of air exchange when the system was running at the highest level. We always had the feeling that the house was stuffy. After several conversations with our installer, a Zehnder technician finally came and found a defective sensor. Many thanks at this point to the technician Mr. Fessel, thanks to him our ventilation system worked properly for the first time within an hour after more than 2 years. You immediately noticed that the house was no longer stuffy, the system now had 340m3 of power at the highest level, twice as much as before the technician's visit. On his advice, I created an automatic program with the Zehnder app, after which the system ran from 11 p.m. to 7 a.m. on level 1, from 10 a.m. to 4 p.m. on level three and between these two times on level 2.

Unfortunately, the system then only worked properly for two months. The system has been doing what it wants since mid-May. Regardless of whether automatic or manual operation is set, it goes to the highest level 3 after a day at the latest and runs at full throttle and no longer regulates down. So pretty much the opposite problem we had in the first two years. As a result, the system is firstly very noisy, which is an issue at night and secondly, Mr. Fessel recommended to us in March not to let the system run at full steam for a long time because of longevity and wear. Which sounds logical.

On May 20th, 2020, my installer informed the service technician Mr. Fessel by email about the new problem. On 02.06.20 came the information that Zehnder has opened a ticket (# 47044). On June 24th, 20, my installer again asked Zehnder by email and pointed out that no one has yet contacted the customer.

Today is August 2nd, 2020, there is still no reaction from Zehnder, that's two and a half months now! I generally understand that in times of Corona, more patience from the customer is required to process complaints, but after two and a half months without any reaction, my patience is at an end.

You can always tell how good a company is by how it behaves when something isn't going so well and how the company then deals with this situation.

I personally regret the decision for a ventilation system, both financially and annoyingly. Maybe it would have worked better with another manufacturer, unfortunately I cannot judge that.

In conclusion, I can only advise Zehnder from my personal experience.