Indirect water heater

An indirect water heater is a specialized storage tank designed to heat water using an external heat source, such as a boiler or a heat pump. Unlike standalone electric or gas heaters, these units utilize the primary heating system to transfer thermal energy through an internal heat exchanger coil. They are commonly chosen for residential and commercial buildings where a central heating system is already installed. By integrating with existing boilers, these heaters provide a consistent and reliable supply of domestic hot water. They are highly valued for their energy efficiency and ability to handle high demand periods effectively. Selecting the right model ensures optimal performance and compatibility with your existing heating infrastructure.

Use cases of indirect water heaters

Indirect water heaters are primarily used in systems where a central boiler is the main source of heat. Common applications include:

• Single-family homes with gas, oil, or solid fuel boilers.
• Large residential buildings requiring high-volume hot water storage.
• Commercial facilities that benefit from utilizing existing heating system capacity.
• Integration with renewable energy sources like solar thermal collectors or heat pumps.

Types of indirect water heaters

These units are categorized based on their design and installation requirements:

• Single-coil models: Designed for connection to a single heat source, such as a standard boiler.
• Dual-coil models: Feature two heat exchangers, allowing connection to two different sources, such as a boiler and solar panels.
• Floor-standing units: Typically larger capacity tanks designed for installation on the floor.
• Wall-mounted units: Compact versions suitable for smaller spaces or utility rooms.

Key features to consider

When evaluating indirect water heaters, focus on the following technical specifications:

• Tank capacity: Must match the hot water consumption needs of the household.
• Heat exchanger surface area: A larger coil surface area ensures faster heat transfer.
• Insulation quality: High-quality insulation minimizes heat loss and improves energy efficiency.
• Material: Stainless steel or glass-lined steel tanks offer different levels of corrosion resistance.
• Compatibility: Ensure the unit is compatible with your boiler's output and control system.

How to choose an indirect water heater

Choosing the correct unit involves assessing your specific requirements:

• Calculate daily hot water demand based on the number of residents and bathrooms.
• Verify the heating capacity of your existing boiler to ensure it can support the water heater.
• Consider the available installation space and choose between floor-standing or wall-mounted configurations.
• Check the energy rating to ensure long-term operational cost efficiency.
• Consult with a professional installer to confirm compatibility with your current plumbing and heating setup.

Which water heaters are the most popular and affordable in 2026?

The full list of popular models at affordable prices is available on this page. In 2026, the following models show high demand and an excellent price-to-quality ratio:

• Ariston VELIS TECH WIFI 50 EU Electric Water Heater, 45L, 1500W, Horizontal/Vertical for 345.49€
• Ariston VELIS TECH WIFI 80 EU Electric Water Heater, 65L, 1500W, Horizontal/Vertical for 402.49€
• Ariston VELIS TECH WIFI 100 EU Electric Water Heater, 100L, 1500W, Horizontal/Vertical Installation for 425.99€

Why is it worth buying water heaters at AiO.lv?

At the AiO.lv online store, you can place an order at a great price with delivery across Latvia — to Riga, Daugavpils, Liepaja, Jurmala, Ventspils, and other cities, as well as throughout Europe. We offer products from leading manufacturers: ARISTON, Haier, CATA, TEESA, NOVEEN, stiebel eltron, KOSPEL, TESY, REGENT, NOVA TEC, TERMOMAX. When you shop with us, you get:

• official warranty and guaranteed quality;
• convenient payment options (including installment and credit);
• fast and reliable delivery across Latvia and to any EU country.

FAQ

Where can you find a water heaters with cheap prices?

You can buy cheaper at the AiO.lv online store. We offer competitive prices and regular discounts, so you always have the chance to find a great deal.

What is the delivery time for water heaters?

If you place your order today, delivery will take between 1 and 5 business days depending on the chosen method.

How long is the warranty period for water heaters?

Our store provides an official manufacturer’s warranty ranging from 12 to 36 months, depending on the model and brand. If needed, you can always contact our customer service department or the manufacturer’s authorized service center for support.

Are water heaters purchasable with leasing?

Yes, if the selected product costs more than €50. You can learn more about installment purchase options and the terms of application on the Payment page.

Can water heaters be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and throughout Europe. All product prices are shown with VAT included. In certain cases, a 0% VAT rate may apply — for example, when purchasing from other EU countries with a valid VAT number. We issue an invoice immediately after the order is placed, support BIS electronic invoices, and automatically generate all required accounting documents. To complete a purchase for a company, simply select the company profile during checkout.