Fire on Water: How Flame-on-Water Bowls Work
A fire on water bowl is a pool feature that makes guests stop and look: a flame that seems to rise straight out of still water. The trick is a gas manifold set a few inches below the surface and an ignition system built to live underwater. This guide explains how the effect works, how it differs from a fire on glass water bowl, what the ignition system asks of your installer, and how to keep it looking right year after year.
What you are actually seeing
Look closely at a fire on water bowl in the evening and you will see a pool of still water with flame dancing across its center. Nothing mechanical shows. Underneath, a gas manifold sits below the waterline. Gas leaves the manifold, bubbles up through the water and is lit at the surface by a pilot that sits just above it. The water hides the hardware and softens the base of the flame, so it appears to float.
Fire by Design, the maker of the fire on water bowls we carry, is precise about the geometry. Its SUBEIS manual says the manifold must be submerged 3 inches below the water surface, and that the water must not rise above the bottom of the pilot's burner cage. That narrow band is the whole design: enough water over the manifold to hide it, not so much that it floods the pilot.
Fire on water, fire on glass and fire and water bowls
Three kinds of pool bowl get mixed up in conversation, and they behave very differently. The difference is where the water goes relative to the flame.
| Type | Where the water is | Where the flame is | The look |
|---|---|---|---|
| Fire on water | Held in the bowl, over a submerged manifold | Rising through the water surface | Flame floating on still water |
| Fire on glass water bowl | Carried past the fire through a plumbed scupper, then spilling out | In a dry interior, on glass | Fire on top, water falling from the side |
| Fire and water bowl | Spilling from a scupper or spillway | In a dry burner area of the same bowl | Fire in the bowl, a sheet or spout of water into the pool |
Slick Rock Concrete explains its Cascade fire on glass bowls this way: the water bypasses the fire components through a plumbed scupper, which leaves the interior of the bowl dry for a traditional electronic or match lit fire unit. It is a lovely effect, and it is a different thing from fire on water. In a fire on water bowl, water and flame share the same space on purpose. If you want water spilling into the pool and a classic fire on glass above it, a fire on glass or fire and water bowl is the right family. Our guide to how fire and water bowls work covers those in depth.
The ignition system behind the effect
Fire by Design calls its SUBEIS (Submersible Electronic Ignition System) the first fully submersible ignition system on the market, and it describes it for pools, fountains, basins and custom water features. A few details from its manual shape how your installer plans the job:
- It must live in water. The manual is emphatic that the system must be installed in water, and that operating it outside water will damage the wiring to the pilot burner.
- Low voltage only. SUBEIS runs on 24 volts AC or 30 volts DC depending on the model, and the manual warns that powering it with 120 volts AC will cause damage.
- Two capacities, two voltages. Models are listed at 290,000 or 510,000 BTU valve capacity, each in a 24 volt AC and a 30 volt DC version, for natural gas or propane.
- A different gas pressure. The manual lists a gas inlet pressure of 1 to 2 psi. That is several times the 7 inch water column nominal natural gas pressure listed for Fire by Design's standard AWEIS system, so your gas professional plans the supply around this number from the start.
- Licensed installation. Fire by Design calls for installation by a locally licensed, qualified service technician.
None of this is something an owner handles day to day. It matters at the ordering stage, because the version of the system has to match where the bowl will sit.
Placing it near the pool
Many fire on water bowls end up on a pool edge or raised beam, where their reflection works hardest. For any automated feature within 5 feet of a pool or spa, Fire by Design's pre-installation checklist requires its 30 volt DC setup: the 30 volt DC system, its 30 volt DC power supply certified for use near swimming pools, and the gas line bonded at each fire feature. The power supply's manual also says the supply itself must not be installed within 10 feet of a swimming pool.
Because SUBEIS comes in both voltages, confirm which one your bowl ships with before you fix its position. If the bowl will sit inside that 5 foot zone, tell us when you order and we will confirm the configuration with Fire by Design. Bonding, ground-fault protection and the final layout belong to your licensed electrician and your local inspector. Our pool planning checklist sets out who does what.
Design notes: shape, still water and night
Fire on water rewards simple forms. The effect needs a calm surface, so wide, shallow bowls with a clean rim read best, and the bowl itself becomes the frame for the flame. The round shapes (Zen, Vessel and the Wok) feel soft and organic next to a freeform pool. The flared square Spartan, and the Legacy and Geo shapes with their crisp lines, suit a rectangular pool with a stone or porcelain coping.
Think about the view from the house. Fire on water is at its best when you can see the water surface as well as the flame, so a bowl set at or slightly below eye level from a lounge chair looks better than one perched high on a column. At night, the water catches the flame from below and the whole bowl glows. A little low, warm lighting nearby helps the concrete read after dark without competing with the fire.
Fire by Design also offers its PPHX shapes (Wok, Oblique and Tuscany) in "fire-on-water ready" configurations, according to its product page, so a shape you like as a fire bowl may be available in this configuration. Ask us before you rule a design out.
Here are the fire on water bowls in our collection, all from Fire by Design.
You can also compare them with the fire and water bowls if you would rather have water spilling into the pool.
Living with a fire on water bowl
Most of the ownership experience comes down to the water level and a clean bowl. Leaves, blossoms and pool toys find their way into any bowl near a pool, and a submerged manifold is not somewhere you want debris. Fire by Design's manual asks you to check for leaves and other debris before turning the system on, and to have a qualified service technician inspect it at least once a year.
- Keep the water at the level your installer set. Evaporation on a hot day lowers it, and a heavy rain can raise it.
- Never run the fire with the bowl drained. The manual is clear that operation outside water damages the pilot wiring.
- If the bowl will be drained for winter, keep the fire off until it is refilled and checked. Our winterizing guide covers the rest.
- Care for the concrete as you would any pool bowl. See caring for pool bowls.
Common questions
How does a fire on water bowl work?
A gas manifold sits under the water in the bowl. Fire by Design's submersible system calls for it to be 3 inches below the surface. Gas bubbles up through the water and is lit by a pilot that sits just above the waterline, so the flame appears to rise out of the water while the hardware stays hidden. The system is built to be installed and operated in water.
What is the difference between fire on water and fire on glass?
In a fire on water bowl, the flame rises through the water itself. In a fire on glass water bowl, such as Slick Rock's Cascade, water is carried past the fire through a plumbed scupper and spills out of the bowl, while the fire burns on glass in a dry interior. Both pair well with a pool, but they look and behave quite differently.
Can a fire on water bowl sit right at the pool edge?
It can, with the right configuration. For features within 5 feet of a pool or spa, Fire by Design requires its 30 volt DC system, its certified 30 volt DC power supply and a bonded gas line at each feature. The power supply itself must be at least 10 feet from the pool. Your electrician and local inspector confirm the final layout.
Can I run the fire if the water is low?
No. Fire by Design's manual says the submersible system must be installed in water and that operating it outside water will damage the wiring to the pilot burner. Keep the water at the level your installer set, top it up after hot, dry spells, and leave the fire off whenever the bowl has been drained.
Sources
- Fire by Design, FBD-0002 SUBEIS Ignition System Instructions, REV 090826, pp. 1, 4 to 5, 7 to 8, 12 to 13
- Fire by Design, Submersible Electronic Ignition (SUBEIS) product page
- Fire by Design, FBD-0001 AWEIS Ignition System Instructions, REV 090826, gas pressure table
- Fire by Design, Pre-Installation Checklist: Automated Fire Features, REV 090226 r5, section "Any feature within 5 ft of a pool or spa"
- Fire by Design, PS Series Low Voltage LED Driver instructions, installation warnings
- Fire by Design, PPHX GFRC Bowls product page, configurations
- Slick Rock Concrete, Cascade Water + Fire (fire on glass) page, "How it works"
Brands we carry
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Prism Hardscapes
Prism Hardscapes lookbook: Tavola tables, Moderno bowls, Lombard pedestals, the Pool Collection and PH IGNITE, with finishes, fuel options and warranty terms.
Warranty: 2-year limited warranty against manufacturer defects (Prism Hardscapes Warranty)
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Slick Rock Concrete
Slick Rock Concrete lookbook: handmade Texas Hill Country Cascade water bowls, RidgeLine and Oasis fire pieces, twelve stained colors, ignition and warranty.
Warranty: Concrete 1 year (structural cracking and sealer failure) and composite 2 years (Slick Rock Warranty and Liability)
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Fire by Design
Fire by Design lookbook: GFRC fire, fire and water and fire on water bowls with AWEIS ignition, pool requirements near water, care and warranty terms.
Warranty: Bowls 2 years from delivery date and electronic ignition systems 3 years residential or 1 year commercial (Fire by Design Limited Warranty)
