In the summer of 2009, the idea came to me to install an alternative heating method alongside the gas heating in our family house built in 2002. We felt the need because, in the winter of 2008, during the gas supply problems in Ukraine, the gas provider supplied gas with a significantly lower calorific value than before. The gas flame burned red instead of blue (due to increased moisture content), and the previous gas price subsidy was also discontinued.
A relatively solid starting point was that, during the house’s design, we built a second chimney in addition to the one for gas heating. I consulted multiple times with the building services engineer about which heating system to install, considering its efficiency and installation cost.
We explored the following options:
1. Tiled stove
2. Traditional fireplace
3. Air-heated fireplace
4. Water-heated fireplace
5. Multi-fuel boiler
6. Pellet fireplace
7. Simple cast-iron stove
1. Tiled stove: Besides offering the highest efficiency, it is the trendiest secondary heating option. I showed the site to a master fireplace builder, from whom I learned the following:
It is unwise to build an approximately 900 kg tiled stove above underfloor heating pipes, especially since there is impact-resistant thermal insulating polystyrene beneath the heating pipes. (concrete can collapse under heavy weight)
The tiled stove’s characteristic is that it begins to release heat intensively about an hour after lighting, and it continues to emit warmth for a long time. This doesn’t quite fit with our family’s lifestyle, because the fire lit in the afternoon when coming home would release heat throughout the night in the living room, while the family is already asleep in the bedrooms on the other side of the house.
2. Traditional fireplace: It emits a great deal of heat, but only to a single room. The warmth also extends to the other rooms, though only sparingly. Its price is barely lower than that of the water-heated fireplace.
3. Air-heated fireplace: Slightly better than a traditional fireplace, but requires a solution to channel air into adjacent rooms.
4. Water-heated fireplace: Marries the benefits of a traditional fireplace with those of a multi-fuel boiler. The drawbacks are the high initial investment and the costly plumbing work needed to link the fireplace with the existing heating system.
5. Mixed-Fuel Boiler: The simplest and, in my opinion, the best option. Unfortunately, it wasn’t feasible here because the chimney was located in the living room. Where installation is possible in a boiler room or basement, it can work wonderfully and create even less mess.
6. Pellet Fireplace: Growing in popularity in our country as well, but for now, both the equipment and the fuel remain costly. More advanced units use not only wood pellets but also low-quality, inexpensive corn and barley. Obtaining the available government subsidies is almost impossible…
7. Cast iron stove: The most affordable and easiest to install. It’s not a long-term solution because, unfortunately, the inserts burn out within a few years, and the firebrick lining is also hard to replace.
I decided on a water-heated fireplace, and the plumber agreed to connect it alongside the gas heating system. A 500-liter buffer tank is recommended, but I was hesitant to install it. Besides the production cost of 150,000 HUF plus insulation, I didn’t want to place a 700 kg heavy monster on my wooden-beamed attic floor. It is certainly a good idea, and building engineers recommend it as well, but starting from traditional mixed-fuel open systems, I chose not to implement it. In my opinion, using it would result in significant loss, and the large volume of water would cause the system to have considerable inertia. I believed—something that has since been confirmed, as the system works perfectly—that underfloor heating would serve as a suitable buffer for us, and instead of a buffer tank, I preferred to invest in controlling the airflow of the water-heated fireplace.
Among the water-heated fireplace models, I chose the Edilkamin Idro 50. Edilkamin has a nationwide service network and even an office in the neighboring town. There was a summer fair where you could purchase with a 10% discount, just before the VAT increase.
I first placed the combustion chamber on two sets of two 10 cm Ytong blocks, making sure its legs rested on the Ytong, while maximizing the distance between them to leave enough space for wood storage. The smoke pipe measures 2 x 50 cm and includes a 45° elbow.
Finally, during installation, we placed the combustion chamber on 2 x 3 Ytong blocks, raising the firebox higher and making it easier to manage. On the upper left is the supply pipe, on the lower right the return pipe, and on the upper right the copper pipe leading to the expansion tank.
Above the gas boiler is the circulation pump of the open system. We installed the expansion tank in the attic. The open system connects to the gas boiler’s closed system via a heat exchanger.
The system uses air from the attic for combustion, not the already warmed air from the apartment. We routed a 120 mm aluminum flexible pipe from the attic, which connects to the combustion chamber through a paddle controlled by a cable.
The circulating pumps are controlled by a pipe thermostat, which can be adjusted and replaced through a grille.
I personally designed and built the frame of the casing using Ytong. For the adhesive, I used high-quality flexible tile glue.
Meanwhile, the official commissioning took place with the first lighting. To validate the warranty, the professional service must confirm that the connection is correct and that the system is safe.
On the left side of the fireplace, I designed a triangular seating area. Below the firebox is the wood storage compartment, which also facilitates airflow from bottom to top behind the firebox.
I had the baseboard cut by a stonemason from 3 cm thick granite. It is important to ensure that no part of the cladding touches the firebox. A minimum 5 mm gap must be maintained, as heat can cause cracking in either the cladding or the baseboard.
I built the side wall using 10 cm Ytong blocks. I ensured the elements were bonded together, and that the lintel was likewise connected in bond.
For the lintel, I used a reinforced concrete Ytong lintel. Both its length and thickness had to be cut to size for a perfect fit.
Before applying the cladding, I smoothed the Ytong with tile adhesive. I strengthened both the lower base and the upper sidewalls with Dryvit mesh to prevent any potential cracking.
Choosing the material and color for the cladding was not easy. We discovered a Syrian white limestone cladding at a nearby stone gallery, measuring 7 cm high and approximately 1–2 cm thick. Limestone is easy to cut and carve. At the corners, I beveled the slab edges at a 45° angle, resulting in a cleaner fit. I made sure the cladding didn’t touch the fireplace anywhere, leaving a 5 mm gap all around.
I left out the upper ledge and didn’t fully cover the sides. Next came the dome, which I constructed from fire-resistant drywall and secured to a metal drywall profile.
At the meeting point of the dome and ceiling, I applied two layers of fire-resistant silicate fiber insulation boards, as warm air accumulates at the top of the dome. Since the ceiling has a wooden beam structure, I took extra care with the insulation and installed the insulation boards with overlapping joints.
[PIC-ROW img=tu/vizteres-kandallo-epitese-csinald-magad-sn16_n]Installation of a water-heated fireplace firebox (Norbert Stier)[/PIC-ROW]
The heat gathered in the dome warms the cold air inside the aluminum pipe descending from the attic.
I positioned the fire-resistant silicate fiber insulation board, leftover from the full panel, between the water tank and the lintel. The firebox is hottest there, so that’s where it would best warm the outer cladding. I angled the boards to direct the heat toward the back of the dome.
I reinforced the first two edges with metal profiles and drywall screws. I cut two vents into the drywall. One at the top for the hot air outlet, and the other at the bottom where the pipe thermostat can be adjusted or replaced if it malfunctions. The grilles are custom-made from perforated sheet metal.
I crafted the wooden top ledge from 3cm-thick dried oak. After thickness planing, I proceeded with sanding, cutting the corners at 45°, and gluing. I reinforced the corners with metal plates and wood screws.
I reinforced the edges with aluminum edge protectors. I smoothed out the drywall screw holes and the edge protectors using high-quality filler gypsum.
I even had some help painting the dome :o!
And finally, it’s done! The dome is white for now, but later I will paint it cappuccino. I stained the upper oak wooden ledge with rosewood, and it beautifully brings out the wood grain.
The system has been running perfectly ever since. I don’t need to adjust or open and close any valves during operation. The two heating methods switch automatically. When we fire up the fireplace, the gas heating shuts off because the thermostat senses the air warming, and it restarts only when the fireplace cools down and the house gets cold. The fireplace can independently heat a 110-square-meter house. Just 10 minutes after lighting, it delivers a cozy warmth, while the circulation pump carries the hot water to the radiators and underfloor heating. Even after the fireplace has cooled, the underfloor heating continues to provide comforting warmth throughout the night.
The combustion air — drawn not from the room but from the attic — can be finely adjusted using a cable control. When the fire no longer burns but only glows, I can close off the incoming air supply. This means it doesn’t burn out quickly; instead, I can prolong the glowing time, allowing it to release heat longer.
Unlike a traditional fireplace, I’ve noticed that the cladding (10 cm Ytong covered) barely heats up. The curved water tank at the back of the firebox, holding 60 liters, absorbs so much heat through the water that only the flue pipe and the glass emit radiant heat. The entire apartment warms evenly, and with just six logs, it easily raises the whole apartment’s temperature by 1°C in 20 minutes.
Execution, text, photo: Norbert Stier
TL;DR – Brief summary
(Open the arrow if you can´t see it!)
I decided on a water-heating fireplace, and the plumber agreed to connect it to the gas heating system. Of the various types of water-heating fireplaces, I chose the Edilkamin Idro 50 model.
