Hybrid Heat pump Review: Experiences of two winters

In the summer of 2023, we switched to a heat pump with the goal of reducing our energy bill. After two winters using the heat pump from DeWarmte, we can evaluate the benefits and experiences this choice has brought us.

2024 Savings

In this post, we share our experiences with the heat pump in a house from 1970, with first-generation double glazing (and even one single-glass window) and about 200m2 in size.

For the Dutch version of this article: Click here

Why did we choose this Hybrid Heatingpump?

To be honest, purchasing this heat pump was somewhat impulsive. Most heat pumps were hard to get in 2023, especially on short notice. Fortunately, this wasn’t the case with DeWarmte—they were still relatively new and could install it within a few months. The claims made by various parties regarding the efficiency didn’t vary much, and there weren’t many experiences available. What appealed to us most was the price. With a relatively low investment, we could get started. We ultimately paid 4,300 (including the subsidy), which also included the cooling function.

Is our house suitable?

As described, our heat pump needs to heat quite a large area during the winter. The house is old, and you can feel it in the insulation. We’ve lived in this house since 2022 and have added insulation to the cavity walls (Thermofoam) and also to the floor (Foil). The roof still has the original insulation (partly on the roof and partly on the attic floor). We have underfloor heating throughout the house, both upstairs and downstairs. The windows and doors are old and from the first generation of double glazing. You can definitely feel a draft in our home, although we try to minimize it with strips (but let’s just say there’s plenty of ventilation).

We are aware that preventing energy loss is better than solving the problem with a heat pump. However, quotes for replacing the windows and doors range from 40k to 60k, and that’s a lot of gas you could burn through.

Installation and service

The installation of the DeWarmte heat pump went smoothly. It was done by two very friendly Polish men, one of whom spoke Dutch. Due to some miscommunication between DeWarmte and me, we found out that the thermostat (Ecotherm from Remeha) I had and a Google Nest version I still had didn’t work. Fortunately, they had a new version of Google Nest available, and I could have it installed for free. The installer also explained the option to cool the house and ensured that we could participate in a pilot program to try it out at no cost.

What have we saved so far?

The first few months, the pump didn’t run very efficiently. It switched back to the boiler too quickly, meaning we didn’t make much use of the heat pump. However, by the end of 2023, there was an update, and since then, the efficiency has been much higher. In the first winter, we saved around 300 m3 (+- 390 euros), with an additional energy use of 900kWh (+-270 euros). The return on investment with 120 euros for a whole winter was quite disappointing.

This winter has been much better so far. We adjusted the settings on our boiler so that it never kicks in anymore. As a result, the heat pump runs more often and for longer periods. In practice, it runs from sunset to sunrise (which is long in winter). The house does warm up somewhat from the sunlight. The efficiency has been much higher this winter due to this adjustment. Specifically, we have saved 800m3 (+- 1040 euros) of gas (we now only use gas for hot water), and the pump's electricity consumption has hardly increased, now at 1050kWh (+-315 euros). This results in a payback time of about 6 years based on current prices.

Reliability and Maintenance

So far, the DeWarmte heat pump has been reliable and trouble-free. We’ve had it running for two winters, and no maintenance has been required. The pump operates quietly and efficiently, and we haven’t experienced any breakdowns or technical problems. Since the pump requires relatively little maintenance compared to a traditional boiler, we still need to figure out how to carry out maintenance in the future.

What else should you know?

Before you decide to quickly buy a heat pump and turn off your boiler, you should know the following:

We heat at a relatively low temperature (around 18 degrees), which is why the saved gas is quite low. You might think, “Oh, I can get even more efficiency,” and that’s possible. However, we’ve noticed that by turning off our boiler, the heat pump sometimes struggled to keep our house warm enough. Our house is poorly insulated, but we do use underfloor heating. At -2 or colder, we couldn’t get the house warmer than 18 degrees, and the heat pump was running full throttle.

This isn’t a problem for us because such days don’t happen very often (and we could temporarily use kerosene heaters if needed).

But this might not be an option for you.

What should you keep in mind?

To decide if a heat pump is right for you, you should have a good understanding of your goals and how well your home is insulated.

If you currently live in a new house that’s about 10 years old without a heat pump, I don’t think you’ll get your money’s worth. Your energy consumption is likely already so low that you’d be better off investing your money elsewhere.

But if you live in an older house and your energy consumption is above 1200m2, it may be worth seriously considering whether it will be cost-effective for you.

Let us know in the comments what is your experience with a heating pump, or whether you are thinking about purchasing one.