Maintenance contract residential ventilation, cheaper filters

You can easily cut normal filters from mats (except maybe filter cassettes for the central unit). It only costs a fraction.

I did the same. Filter mats for extractor hoods are available in large formats in many hardware stores and supermarkets.
I buy the filter cassette for the central unit separately. Since my wife and I have problems with pollen, we use an F7 filter mat. We have never had as few allergy problems as we do now that we have a ventilation system.

Great answers. Many thanks to everyone!

You should probably do it yourself :) The technician himself recently told me that while he would recommend the maintenance contract/warranty extension for the heat pump, he could not recommend the same for the controlled residential ventilation. Essentially money thrown away.

I would rather ask myself what you actually maintain on a heat pump? Check if there are any leaks and if there is still enough water in the heating system? But there are also people who pay hundreds of euros for the authorized workshop to "properly check" their car. It doesn’t get easier to make money than that. About the filters: - Cone filters in G4 with progressive structure are available for about 1€. I wonder why it should be worthwhile to make them yourself. - Cassette filters are also available cheaply as replicas. I would rather take a cheaper one and change it more often. Vacuuming only removes the coarse dirt here, but the filter still clogs up more and more. Blowing out with compressed air would be better here, but then you spread the dirt everywhere.

I would rather ask what you maintain on a heat pump? Check if there are any leaks and if there is still enough water in the heating system? But there are also people who pay hundreds of euros for the authorized workshop to give their car a "proper checkup." It doesn't get easier to make money.

Actually, I agree with you, especially when it comes to authorized workshops. Although even here, one should differentiate more precisely. But as is often the case, the warranty plays a role here and it expires if you do not have maintenance performed according to the warranty conditions. From my current perspective, a maintenance contract can definitely make sense and even be cheaper than on the open market. An extended warranty costs money, but ultimately it is manageable and bearable. Every small defect costs significantly more than the flat-rate extended warranty for the heat pump. Of course, everyone has to decide and weigh that for themselves.

About the filters: - Cone filters in G4 with progressive structure are available for about 1€. I wonder why it should be worth making them yourself. - Cassette filters are also available cheaply as aftermarket parts. I would rather take a cheaper one and change it more often. Vacuuming here only removes the coarse dirt but the filter still clogs up more and more. Blowing it out with compressed air would be better, but then you also spread the dirt everywhere.

Exactly, the cone filters sometimes cost less than 1 EUR each, so I also don’t start tinkering. But I don’t think these were meant, right?

Regarding the cassette filters, we had a discussion here a few weeks ago and read an interesting point from a user who evaluated the power consumption between different filters. The conclusion was that the "higher-quality original filter" drew less electricity than the third-party filter, so that the calculated costs for electricity and savings when buying the third-party filter ultimately balanced out. I found it interesting to at least include this aspect in the considerations, since I would otherwise never think of considering such side effects.

Right, I didn't think of that either.

I mean the BAFA funding also depended on the maintenance contract for the heat pump...