Air source heat pump often stops working

Hello,

The house is now 1.5 years old, we have a Remko air heat pump for 2 parties. Now the air pump stops working every few weeks. Different error messages. Sometimes the storage needs to be recharged, sometimes there were interruptions in the power supply. The annoying thing is when we want to take a bath, the upper party also bathed, and in the evening you realize, oops, the hot water is not enough. The storage is small.

Is it normal that the air heat pump is so sensitive and stops working from time to time? We then restart it. That means turning the fuse off and on, it starts up, the storage heats up slowly and hot water then takes about 1-1.5 hours (in winter).

After 3 years with our Stiebl air heat pump: So far it has crashed/failed once. After changing the filter, the device must be restarted (reset button, not fuse), which causes it to be regularly rebooted every 3/4 months.

Hello,
that also depends on your settings on the heat pump.
What times have you set for hot water preparation?
What is the setpoint temperature for hot water?
How high is the hysteresis?
Do you have any lockout times?

Hello, that also depends on your settings on the heat pump. What times have you set for the hot water preparation? What target temperature for hot water is set? How high is the hysteresis? Do you have lockout times?

Why do operating settings have an influence on the system stopping? When he restarts the system, hot water is also produced, so it cannot be due to lockout times. Whether the heat pump dimensioning + storage size is sufficient for 2 full bathtubs is another matter,...

Why do factory settings have an influence on the system dropping out?

Are you sure that these are really dropouts, or could it also be due to the settings?

...sometimes there were interruptions in the power supply.

Sounds to me like a blocking time. That's why I ask.

Annoying is when we want to take a bath, the upstairs party has already bathed, and in the evening you notice, oops, the hot water is not enough. The tank is small.

Without calculating, but with a 150l tank at 60 degrees you can fill about 2 bathtubs with 40 degrees warm water rather than with a 150l tank at 45 degrees. :) With our Viessmann you can also set, for example, whether the entire hot water tank or only the upper part is heated. Another example of what it could depend on: Hot water temperature is set to 45 degrees, hysteresis at 8 degrees. Apartment 1 takes a shower => water in the tank is then still 38 degrees => no reheating. Apartment 2 wants to bathe afterwards => at most 38 degrees warm water comes out. So it goes to the heating and restarts it. Due to the removal of the 38-degree warm water, the temperature fell to 37 degrees and then the hot water preparation starts. However, it would have started even without the restart. The numbers are from gut feeling and not calculated, so please don’t take them literally. And this is only one possibility.

Hello,

Is it normal for the air source heat pump to be so sensitive and to stop working from time to time?

No, that is not "normal." However, since I am not a technician, I cannot explain what the cause might be; I think from a distance it would be comparable to looking into a crystal ball.

If you have not signed a maintenance contract for the system, contact your former contractor house builder directly and explain the situation; if you have a maintenance contract, of course, contact the company responsible for maintenance. After that, a technician should come to you and check the system. Maybe it is "just" a matter of adjustment, maybe a minor part needs to be replaced, maybe the system needs to be replaced... many possibilities.

In any case, I do not see the necessity to repeatedly shut down the system for it to work properly. Nor do I see it as your responsibility to get to the bottom of the cause or to make setting changes on the device "on a hunch."

Best regards from the Rhineland