Combi Boilers

What is a fully condensing combi boiler?

A combi boiler is a natural gas appliance that meets the home's heating needs and simultaneously provides on-demand hot water to faucets. Fully condensing combi boilers condense the water vapor in the flue gas and recover the additional heat released back into the system. This way, more heat is obtained from the same amount of gas. The water produced during the condensation process is directed to the drain via the boiler's condensate drain line.

Models in this category

• Baymak Lunatec: Fully condensing combi boiler for residential use.
• Baymak Lambert series: Compact and higher-capacity fully condensing options.
• Baymak Duotec Compact: Fully condensing model with a compact body.

The numbers in product names generally indicate the appliance's capacity class; exact thermal output values are provided in the product description.

How is combi boiler capacity selected?

The home's square footage alone is not sufficient for capacity selection; insulation level, facade orientation, floor position, window area, and climate zone all affect heat loss. Hot water usage also matters: homes where two bathrooms are used simultaneously require higher hot water capacity. An oversized combi boiler may cycle on and off frequently, losing efficiency; therefore, selection based on a heat loss calculation is the most reliable approach. When in doubt, compare your plumber's calculation with the product specifications.

What you need to know before installation

The installation of natural gas appliances must be carried out within a project approved by the gas distribution company and by firms qualified to perform this work. Condensing combi boilers require a condensate drain connection and a suitable flue system. Having the first commissioning performed by the manufacturer's service network is important to ensure the appliance is set up correctly. Clean radiators allow the new combi boiler to operate efficiently; in older systems, radiator flushing before installation is recommended.

Frequently asked questions

Does a condensing combi boiler use less gas?

Because it also recovers heat from the flue gas, it typically meets the same heating demand using less gas; the amount of savings depends on the operating temperature of the system.

Should I use a room thermostat with a combi boiler?

Yes; a room thermostat ensures the combi boiler runs only when needed, improving both comfort and efficiency.

How often should a combi boiler be serviced?

Servicing once a year, before the heating season, is recommended.

What should the combi boiler pressure be?

The recommended system pressure is stated in the boiler's user manual; if the pressure drops frequently, there may be a leak in the system.

What should I do for combi boilers without a visible price?

You can request the current price using the "Request a Quote" button on the product page.