Ämne: New installation, did I made a mistake? (English)

[Kushal Sejwal]

Hello Everyone,

After buying a 150 m2 house one year back, the first thing we wanted to do was to reduce the electric consumption. Our total yearly consumption is 20,000 kWh. Everyone we spoke with, said good things about getting a ground sourced heat pump. We got similarly priced quotes and went for CTC GSi 608 with 180m bore. The installation finished at the end of November and since then we are on holiday, keeping the CTC on holiday mode. I am surprised to see that the electric consumption during the month of December just for heating the idle house was 1700 kWh. Each hour the minimum consumption of the house is 2.3kW. I have kept the radiators on and the temperature of the house has been between 13-17 degrees during this time. Is it normal? Before with my electric boiler, a typical heating consumption for the month of December would have been around  2200 kWh with us not bene on holidays and heating the house to 23 degrees. Is it normal? Where is the 3-4 COP I was hoping to achieve, in my case for December the consumption is not even half. I am missing something, there is some problem with the installation?

Another issue we are facing is the water for the shower. Earlier we never thought of how many people are going to shower one after another. But now we felt just one long shower can deplete the hot water supply and the water starts becoming cold towards the end. This I understand, the water is heated up to lesser degrees than the electric boiler but 300 L at 55 degrees (setting in the CTC pump) should be good for at least 2 showers? Again is this normal for this particular heatpump or some setting can further make this better? Is there a way we can put the heatpump directly on electricity like old electric boiler when we really need that much at the additional consumption cost?

I would be glad if someone can guide us, my wife and I were very excited when we decided to have this installation but now we are thinking if we made a mistake or find an installer who was incompetent or the pump was not suitable for our house? We were looking for an upgrade form our old electric boiler but as of now its looking like a degrade despite the big investment.

Thanks in advance,

Best,

K

[944_Driver]

It sounds like something is wrong.
Is the compressor running at all?
I assume it has counters in the display for how many hours it has been running the compressor and for how many hours it has been running on the electric heater. Take a look at that. Maybe it can also show the number of compressor starts.

If it is running I think we need to take a look at the temperature readings from it while running. Let it run for at least 10 minutes and write down the values and post here. 

With the previous electric heater for hot water you can crank it up to 80-90 degrees, that give a lot of 37 degrees water in the shower, but even 300 liters of 55 degrees water now should give you a couple of good showers. Take a look at your water meter to see how much water your long shower actually consumes.

// Magnus

[Roland]

There is clearly some problem with the installation, the heat pump contributed very little, if anything, to the heating of the house. The average consumption in december was 2,3 kW.

Based on the annual electricity consumption the house seems to be a modern, well insulated house. The heat leakage is probably around 0,15 kW/K. The average temperature in the parts of Sweden where most people live was around 0 degrees which means that in average about 2,3 kW would have been needed to heat a house in this area to 15 degrees. I also ask: is the compressor running at all?

[Carl N]

For the water to the shower, I'm sorry to say that CTC heatpump is not the best stuff.
But I think you can schedule extra heat water production to the time of the day/week when you usually shower.

For heating the building you need to adjust the kurve in the heatpump to your house, and not use the thermostats to adjust indoor temperature.
The thermostats need to be as much open as possible.
But if you lowered the kurve to get lower temperature in the house, then something is not normal.