Home water heating – gas boiler, heat pump, or PVT panels. Which solution should you choose?

Preparing domestic hot water isn't just a matter of comfort, but above all, it's about operating costs, energy efficiency, and the possibility of integrating it with renewable energy sources. For investors, this means choosing a solution tailored to their lifestyle, while for installers and designers, it's crucial to propose a system that will operate stably and economically for years to come. What should we pay particular attention to if we want to heat water efficiently and cost-effectively?

Key Information

• There is no single best domestic hot water system, as its selection depends on the number of draw-off points, available space, gas access, and desired comfort.

• Gas-based instantaneous solutions are a good choice where compactness and quick access to hot water without storage are important.

• A domestic hot water heat pump with an integrated storage tank is suitable for higher water demands and multiple bathrooms.

• Hybrid PVT panels can significantly reduce gas consumption for domestic hot water by over 25%. In modern installations, the integration of a heat source with renewable energy sources and the proper selection of the system to the actual needs of the building are increasingly important.

How to choose a domestic hot water system for the building and the needs of the household?

The first rule is simple: the hot water source should meet the actual demand of users. In an apartment or small premises, small dimensions and easy installation are usually key. In a single-family home, on the other hand, efficiency and the ability to use multiple draw-off points simultaneously while maintaining a stable water temperature become more important. It's worth remembering that oversizing the device means unnecessarily higher purchase and operating costs.

When is a gas boiler or instantaneous water heater the right choice?

A gas instantaneous water heater or combi boiler is ideal where hot water is needed immediately after turning on the tap and there's no space for a storage tank. These devices are best installed close to the draw-off points. Their advantages include compact size and – in modern models – economical operation and stable water temperatures.

However, if the home has a higher demand for domestic hot water, a single-function boiler with a storage tank is a better choice. This solution allows for storing a larger amount of hot water and improving comfort, especially when household members use the kitchen and bathroom simultaneously. An additional advantage of a gas boiler is the ability to operate in summer mode – exclusively for domestic hot water, which reduces gas consumption outside the heating season.

A domestic hot water heat pump – who is it best for?

A heat pump is a solution for those who want to reduce operating costs and increase the share of renewable energy, or who don't have access to gas. Typically, the device heats rooms (central heating) and provides domestic hot water (DHW). In the case of inverter pumps, such as the Termet Heat Titanium Pro, it can also cool rooms on hot days.

There are also lower-power heat pumps available on the market designed specifically for domestic hot water heating. An integrated tank with a capacity of 80 to 300 liters allows for access to hot water even in multiple bathrooms. Such devices are energy-efficient, virtually maintenance-free, and work well with a PV system, allowing the pump to be powered by free electricity.

However, it's important to remember that a heat pump requires a suitable installation site and proper installation preparation (a tank is necessary). In practice, this solution is particularly attractive in new homes or for comprehensive system upgrades. Another advantage is the possibility of applying for subsidies, such as those from the Clean Air program.

PVT panels and hybrid systems: how to reduce domestic hot water costs

Hybrid systems, such as a gas boiler working with PVT panels, are becoming increasingly popular. Photovoltaic-thermal panels simultaneously produce electricity and heat, which can be used to heat water. On sunny days, the PVT can fully meet water heating needs, while in less favorable conditions, the boiler partially or completely takes over this role.

Setup systems such as the Termet GOLD PLUS II boiler with two PVT panels can reduce gas consumption for domestic hot water by over 25% and lower system emissions by approximately 24%. This demonstrates that you don't always have to choose between gas and renewable energy, as a well-thought-out combination often yields the best results.

What to choose in practice?

For apartments, small premises, and low-water consumption points, flow-through solutions are usually sufficient. In single-family homes with higher hot water needs, systems with a storage tank—gas or heat pump—are more suitable. Investors focused on cost reduction and greater energy independence should consider integrating a heat source with PV or PVT.

When choosing a method of domestic hot water preparation, the most important thing is not so much choosing the "most fashionable" solution, but rather selecting the right system for the specific conditions: the building, the number of users, and the desired comfort. In practice, flexible solutions work best, such as a modern gas boiler, a heat pump with a storage tank, or a hybrid system with PVT, designed as a cohesive, efficient system.

You can learn more about the interaction between a gas boiler and photovoltaic panels from Termet S.A.'s Heat Academy on YouTube: