ᐅ Costs of tankless water heaters and infrared heating systems

nordanney schrieb:

I myself have also lived in an apartment with a DLE (direct electric water heater). But you will never find anyone who has a separate meter just for the DLE. That’s the only way to get an accurate consumption reading. And even then, there’s a 300% margin of error, since every person and every household is different (number of people, shower duration, number of showers, hot water used in kitchen, bathtub versus shower, etc.).
I would have estimated my costs there—since I don’t shower daily due to sports and other reasons—as a single person to be around €200-250 (about $220-$275).

That’s by far the highest figure I’ve heard for a DLE, and that’s despite not showering at home daily? That would be about $3,000 per year, can that really be right? And for a single-person household, if I understand correctly? For a family with three kids, that would add up to a staggering $15,000 per year...

But that’s exactly why I am asking for practical experience, just to get a rough idea what actual costs look like—more than a guess it can’t be, since everyone showers differently. The rough calculations you find online are also unrealistic when you compare them to real usage.
If multiple people report similar experiences, then I think the costs could actually be higher than commonly assumed.

nordanney schrieb:

Final remark: no doubts, hot water with a DLE gets expensive if used frequently. But not necessarily more expensive than gas.

I live in my house with a gas boiler (not even condensing, a really old model) and with 4 people, and my gas costs are nowhere close to that.

It really isn’t easy to make the right decision here.

Stiftung Warentest tested electric instantaneous water heaters in 09/2023 and also found that they incur higher costs compared to, for example, heat pumps. However, they also mentioned that a water storage tank in the basement is needed for this. They assumed a water consumption of 41 liters (11 gallons) per person per day and 40 cents per kilowatt-hour. Over 10 years, this results in around €2,000 per person, or €200 per year. I currently pay about 30 cents per kWh, so that would be €150 per year per person. Gas costs about half as much. If I had your email address, I could send you the article.

Of course, performance-wise a heat pump would probably be optimal, but it initially costs significantly more and often tends to be more prone to issues, which can lead to subsequent service costs.

I can understand the approach well, to work with people I know to be reliable, since I have been repeatedly disappointed especially by heating and ventilation contractors. Neither the controlled residential ventilation system nor the domestic hot water heat pump could be properly adjusted by them, and without the manufacturer hotline both would have been completely lost.

For me, this has led to relying on people I can trust and not implementing some things, even if they might have been the better option in theory.

Our domestic hot water heat pump from Vaillant works great, but I hope to avoid the apparently frequent problems others have reported. With the Zehnder controlled residential ventilation, I started tinkering myself after just a few years because our contractor had barely any knowledge and every service call cost almost €500.

You heat your apartment with infrared, so why not heat the water the same way? Generally, I prefer to pay exactly for what I use. Our hot water is heated about 30% of the year completely unnecessarily because we don’t need it.

And someone who doesn’t know the off button can cause costs to explode with any heating system. Our former co-owner in the multi-family house actually managed to consume about six times as much as the rest of us in the bathroom and suspected fraud. When I entered her bathroom, I almost fainted—it was that hot there even with the window tilted open.

It’s not always just about technocratic calculations; for me, stress-free building or renting also has a high value.

If you have craftsmen for everything except gas: Daikin Multi Plus or Hitachi Multi Yutampo.

Air-to-air heat pump as a multi-split system with simultaneous domestic hot water preparation in a wall-mounted storage tank.
One indoor unit per room and the outdoor unit on the balcony. The latter probably needs to be coordinated with the homeowners association. Only 1/3 to 1/4 of the electricity consumption compared to infrared heating and direct electric water heaters, with reasonable investment costs.

dertill schrieb:

The latter probably needs to be coordinated with the homeowners association.

Almost all of these require approval:
- Change of heating system type
- Small core drilling
- External installation

Otherwise, this is of course a good approach.

dertill schrieb:

If you have tradespeople for everything except gas: Daikin Multi Plus or Hitachi Multi Yutampo.

Air-to-air heat pump as a multi-split system with simultaneous domestic hot water generation in a wall-mounted storage tank.
One indoor unit per room and the outdoor unit on the balcony. The latter probably needs approval from the homeowners’ association. Only one-third to one-quarter of the electricity consumption compared to infrared heating and instantaneous electric water heaters, with reasonable investment costs.

That’s quite a complex setup, and you still end up with a boiler hanging somewhere. Meanwhile, someone advised me that if an instantaneous electric water heater isn’t feasible because of the cable size from the basement to the apartment, I could hang an electric storage water heater near the ceiling—I hadn’t thought of that myself. I’m slowly accepting that I might go with this solution.
However, I still hold out hope for a gas-fired water heater. A gas installer who turned off my gas to allow us to remove the very old individual gas stoves sort of hinted that he might be able to install one within a reasonable timeframe. It’s all very vague, but maybe it will work out. I’m hopeful.

Arauki11 schrieb:

Stiftung Warentest tested electric tankless water heaters in 09/2023 and also found that these come with higher costs compared to, for example, heat pumps. It was also mentioned that you would need a water storage tank in the basement. They assumed 41 liters (11 gallons) per model person per day of water consumption and 40 cents per kilowatt-hour. Over 10 years, this amounts to about €2,000 per person, or €200 per year. I currently pay about 30 cents per kWh, so that would be €150 per year per person. Gas costs about half as much. If I had your email address, I could send you the article.
Of course, in terms of performance, a heat pump would probably be optimal, but it initially costs considerably more and is often more prone to issues, potentially leading to higher follow-up tradesman costs.
I can understand the approach well, to implement it with people I know to be reliable, as I have been repeatedly disappointed particularly by heating and ventilation specialists. Neither the controlled ventilation system nor the domestic hot water heat pump could be properly set up, and without the manufacturer hotline, both would have been completely lost.
For me, this meant that I prefer to rely on people I trust and have not implemented certain things even though they might have been better on paper.
Our domestic hot water heat pump from Vaillant works great, but I hope to avoid the apparently rather frequent problems. With the Zehnder controlled ventilation system, I started tinkering myself after only a few years because our contractor had very little knowledge, and each time it cost nearly €500.
You heat the apartment with infrared, so why not heat the water the same way? Generally, I like to pay exactly for what I use. Our hot water is heated pointlessly for about 30% of the year because we don’t need it.
And anyone who doesn’t know how to turn it off can make costs explode with any heating system. Our former co-owner in the apartment building actually managed to consume about six times as much as the other owners in the bathroom and suspected fraud. When I entered her bathroom, I almost fell over because it was so hot there, despite the window being ajar.
It’s not always just about technocratic calculations; stress-free building or renting also has a high value in my opinion.

I also find it very tempting; it’s just really simple to run everything on electricity, no complex systems. I just have some concerns about the costs, which may be unfounded, but so far I haven’t found reliable information showing that the costs aren’t much higher than, for example, gas.