Hydronic and radiant floor heating
Hydronic heat is water doing the work, carrying warmth from a boiler out to your floors, your radiators, your baseboard, even your driveway. It is quiet, it is even, and it warms the surfaces of a room rather than the air. Family owned in Pittsburgh since 1980, we work the full range, from two hundred year old houses to new gymnasiums and fire stations.
Hydronic heating at Wahl, the short version
What does Wahl's hydronic department install and service?
Hydronic is a department here, not a side line. We install and service boilers, radiant floors, radiators, baseboard, steam, snowmelt and hydronic hot water, in houses older than the neighborhoods around them and in new gymnasiums and fire stations.
Family owned in Pittsburgh since 1980, 55 team members, more than 40 trucks, an 87,000 square foot facility on six acres in Oakdale, licensed and insured, master plumber on staff, PA HIC #PA022302, A+ with the BBB.
- New boiler installationFull system design and installation, residential and commercial.
- In-floor radiant heatNew construction slabs and retrofits into houses that are already standing.
- Radiators and baseboardHydronic baseboard, Buderus panel radiators, and existing cast iron radiators kept in service.
- Domestic hot waterCombi boilers and indirect water heaters that make household hot water off the boiler.
- Hot water coilsA coil in a duct system so boiler heat and air conditioning share one set of ductwork.
- Steam systemsSteam boiler replacement and repair, including repiping in houses older than the street they sit on.
- Towel warmers and steam showersHeated towel warmers and steam generators for showers.
- SnowmeltDriveways, walks, ramps and fire station apparatus aprons.
- Service on systems we did not installWe repair hydronic and steam systems that somebody else put in.
Why do we heat with water instead of blowing hot air?
Water carries heat far better than air, so a small tube moves the heat a large duct moves. That buys quiet operation, easy zoning, no blowing dust, and comfortable rooms at a lower air temperature because the surfaces around you are warm.
Does a hydronic system cool the house in the summer?
No. Hydronic heats, it does not cool. In a radiant house, cooling comes from separate equipment, either ductless heads or a ducted system sized for the cooling load, and we design that side here alongside the heat.
Designing both at once keeps air conditioning from turning into a second project with a second company.
Mitsubishi Diamond Elite contractor | Ductless and ducted cooling for radiant houses, including rooms with no ductwork to work with.
Bosch cold climate dealer | Heat pump equipment built for real Pittsburgh winters.
Rheem Pro Partner | Ducted heating and cooling equipment sized to the calculated load.
How does a heated floor actually heat a room?
In a radiant floor, the floor is the radiator. Tubing carries warm water through or under the surface, the whole floor gives that heat back gently, and you are comfortable at a lower thermostat setting than an air system needs.
Radiant floors run at low water temperatures, often far below what old baseboard needs, and cool return water is exactly the condition a modern condensing boiler is happiest in.
Can radiant floor heat go into a house that is already built?
Usually yes, and retrofit is where most Pittsburgh homeowners land. Which method fits depends on whether we can get under the floor, how much height you can give up, and what is going on top.
In a lot of older city houses the basement or crawlspace is open enough that the whole job happens from underneath and the finished room above is never touched.
- Heat transfer plates under the subfloorWorked from the basement or crawlspace, with no demolition in the room above.
- A thin pour over the existing subfloorAn option where the floor height and the framing allow the added buildup.
- Above-floor panel systemUsed when there is no access from underneath at all.
- New slab workOn new construction we prep the floor and set and tie the tubing for the concrete crew.
Who does what when radiant goes into a new slab?
We design the system, prep the floor, set and tie the tubing, and run it out to the manifolds. We do not pour the concrete. Your concrete contractor pours, and we come back afterward to finish the mechanical side.
- Design firstRoom by room heat loss, loop layout and water temperatures, before anything is ordered.
- Floor prepWe prepare the floor so the tubing sits exactly where the design says it should.
- Tubing set and tiedLoops are laid out, tied down and run out to the manifold locations.
- Coordination with your concrete crewWe talk to them directly so the tubing is protected and nobody is guessing.
- The pourYour concrete contractor places the slab. We do not pour concrete.
- Mechanical finishOnce the slab is down we come back in for the boiler, the manifolds and the controls.
Which floor coverings work over a heated floor?
Tile and stone are the best partners for a radiant floor. Engineered wood works inside the temperature limits its manufacturer publishes. A thick carpet over a heavy pad fights the system, so it changes the design.
That conversation belongs in design rather than in December, because the covering you choose sets the supply water temperature we design the whole zone around.
| Floor covering | How it behaves over radiant | What it means for the design |
|---|---|---|
| Tile and stone | Conducts heat beautifully and gives it back fast | The easiest covering to design around, and it takes the widest range of water temperatures |
| Engineered wood | Works well inside the temperature limits its manufacturer publishes | Those published limits drive the supply water temperature for that zone |
| Thick carpet over a heavy pad | Insulates the floor from the room and fights the system | If the carpet is staying, we plan the room around it or use a different emitter in that space |
What do you get in the free in-floor design?
Wahl does in-floor heating engineering and design at no charge. Not a rough sketch on the back of a proposal, an actual design, with equipment sizing that follows from calculated numbers instead of a rule of thumb.
Builders, architects and general contractors are welcome to use this too. We hand over a drawing your concrete crew and your inspector can work from, and we talk to them directly so the pour goes clean.
What goes wrong when a radiant floor is designed by rule of thumb?
The design is what decides whether you love the floor or fight it. Most of what goes wrong is not fixable later without opening the floor, which is why the design deserves the hours up front.
Loops that run too long | The far end of the circuit starves and that part of the room never comes up.
Spacing that ignores the exterior wall | You get a cold band along the windows, where the heat loss is highest.
A water temperature picked for tile | Run that same temperature under engineered wood and you are outside what the flooring manufacturer allows.
Zones drawn on a floor plan | Zones should follow how the family actually lives, not how the rooms happen to sit on paper.
Equipment sized by rule of thumb | A boiler picked without a heat loss calculation is a guess you live with every winter.
Which boilers do we install and service?
We install and service Weil-McLain, IBC and Rheem. Two families of equipment really: modulating condensing boilers with stainless or aluminum heat exchangers, and traditional cast iron boilers that vent up an existing chimney.
- Weil-McLainUltra, Evergreen, ECO, CGi and CGa, all of it.
- IBCCondensing boilers and combi boilers.
- RheemBoilers and combi boilers.
- Outdoor reset controlWater temperature tracks the weather instead of running flat out.
- Indirect fired water heatersSized to real fixture demand rather than to the box they come in.
- Steam boilersReplacement and repair, with the near-boiler piping built to the manufacturer's drawing, because a steam boiler piped wrong never behaves.
Condensing or cast iron, which one fits your house?
A condensing boiler earns its efficiency by taking heat out of its own exhaust, which only happens when the water coming back from the system is cool enough. Radiant floors return water cool by design, so the two are a natural pair.
The rule we work by is that the equipment has to match what the system can feed it. A condensing boiler tied to a loop that never sends cool water back will not deliver the efficiency printed on its label.
No amount of controls fixes that after the install, which is why the choice belongs in design.
A modulating condensing boiler fits when
- The system returns cool water, radiant floors or low temperature panel radiators for example.
- You want outdoor reset, so the system spends the winter running long, quiet, low fire cycles instead of slamming on and off on a forty degree day.
A cast iron boiler is still the right call when
- The house has high temperature baseboard, a good chimney and a simple layout.
- Return water comes back hot, which cast iron takes without a penalty.
What separates a good boiler room from a bad one?
How the boiler room is piped matters as much as what is in it. We run primary and secondary piping straight, set circulators and air separation where they belong, and label every zone valve and shutoff.
Labeling means the next person to open that door, including us in ten years, can read the system right off the wall.
Combi boiler or indirect water heater?
A combi boiler makes heat and household hot water out of one cabinet. An indirect water heater is a storage tank heated by a coil from the boiler, with no burner and no flue of its own. We size either one to the house.
Domestic hot water is the fork in the road on most boiler replacements, so we settle it during design rather than on install day.
A combi boiler fits when
- Space is tight and you would rather not keep a second appliance.
- The home is on the smaller side and hot water demand is steady rather than heavy all at once.
An indirect water heater fits when
- Several bathrooms can run at the same time, because an indirect recovers hard.
- You want storage sized to the actual house, not to the box the tank came in.
What if the floor cannot be raised even an inch?
Buderus panel radiators are the quiet workhorse of a retrofit. They hang on the wall, respond fast, and run happily at lower water temperatures, so they pair with the same condensing boiler that feeds your floors.
If you already have cast iron radiators, think twice before ripping them out. Sometimes the right job is repiping and rebalancing what you already own, and that is worth deciding before anything gets torn out.
Why do we install hydronic heated floors instead of electric mats?
Wahl installs water based hydronic heated floors and does not install electric floor mats. The reason is serviceability. An electric element is bonded into the thinset under your tile, so a failure means demolition, not repair.
Energy rates move around, so we are not going to print a multiplier on a web page. The direction has held in southwestern Pennsylvania for a long time.
Warming one small bathroom, that operating cost difference is easy to live with. Across a whole floor or a whole house, it compounds every winter you own the place.
| Comparison | Hydronic floor, what we install | Electric mat, what we do not |
|---|---|---|
| Where the heat comes from | Warm water from the boiler that already heats your house | An electric resistance element on its own separate system |
| If it stops working | Boiler, circulator, manifold and controls are all reachable in the mechanical room | The tile comes up, the element comes out, and the floor gets built again |
| Inside a shower | Nothing in the wet area ever needs service | Reaching the element means cutting the waterproofing that keeps water out of the framing |
| Cost to run | Runs off a high efficiency gas boiler you already own | Electric resistance costs substantially more per unit of delivered heat |
| Adding on later | Warm a bathroom now, extend to the kitchen next, add snowmelt at the front steps after that, all off the same plant | Each new area is another standalone system |
| The part buried in your floor | Tubing, the one component that never needs us | The heating element, the one component most likely to fail |
When is an electric mat the honest answer?
We can get electric mats. We choose not to install them, and we would rather tell you the reasoning than quietly leave it off a proposal. Electric mats exist for a reason, and there are jobs where one is the right call.
If your job looks like the list below, we will tell you plainly that we are not the company for it, rather than put something in your house we would not put in our own.
No boiler and no plan to add one | One small bathroom floor to warm, in a house where running hydronic to that single room is simply not practical.
Floor height is critical | So tight that even a thin buildup will not work.
Comfort rather than heat | You want gentle floor warming underfoot instead of real space heating.
Why do fire stations and gymnasiums heat with a radiant slab?
An apparatus bay loses its heated air the second the door rolls up, and an air system has to start over. A radiant slab does not, because the heat is stored in the concrete itself.
The bay comes back faster, and the warm slab helps dry the floor after the trucks come in wet. Snowmelt in the apron and the ramp keeps the crew off ice on the way to a call.
Heated air climbs, so in a tall room much of what you paid for ends up sitting at the ceiling. A radiant floor puts the heat at the level where people actually are, with no air movement at all.
- Fire and EMS stationsApparatus bay slabs and apron snowmelt, one of our favorite hydronic jobs because the building is a textbook case for it.
- GymnasiumsEven heat with nothing blowing over the court, which anybody who has played under ductwork understands.
- Churches, shops and warehousesHigh ceiling buildings where heated air would otherwise stack up at the roof.
- New commercial slabsWe set and tie the tubing for the concrete crew, then finish the boiler room after the pour.
How do we build a residential snowmelt system?
Residential snowmelt is real work, not a novelty. Driveways, walks, front steps and accessibility ramps. We scope it carefully, because heating the tire tracks and the walk you actually use is usually smarter than heating the whole lot.
- Scope the areaWe map the tire tracks, the walk and the steps that actually get used, instead of blanketing the entire lot.
- Design the loopsTubing layout and spacing for the slab, sized off the boiler that will feed it.
- Separate the fluidA glycol loop runs through a heat exchanger so the boiler side of the system stays clean.
- Sensor in the slabA slab sensor tells the system what is happening in the concrete, not what a wall thermostat guesses.
- Set an idle temperatureThe slab idles warm, so the system is never trying to wake a dead cold slab up in the middle of a storm.
How does Wahl price hydronic work and handle a boiler down in January?
Everything we do is flat rate. You get the price in writing before the work starts. We run 24/7 emergency service, and we are a PRAXIS S-10 member company, which means we hold ourselves to an outside standard.
Call (412) 276-9245 and tell us it is hydronic work. You will get people who do this trade every week, not people who dabble in it.
- Flat rate pricingYou get the price in writing before the work starts.
- 24/7 emergency serviceBoilers do not pick convenient nights, so somebody is available around the clock.
- Family owned since 1980Started by John Wahl and run today by the next generation, out of Oakdale.
- More than 1,612 five-star Google reviewsAt a 4.8 rating from Pittsburgh homeowners.
- Licensed and insuredMaster plumber on staff, PA HIC #PA022302, A+ with the BBB.
Let us reach out to you
Fill out the quick form and we will call you back. For an emergency, call any time at (412) 276-9245.
Questions, answered
Is the in-floor heating design really free?
Yes. Wahl does in-floor heating engineering and design at no charge: room by room heat loss, loop layout and spacing, manifold and zone plan, supply water temperatures, and equipment sizing. You get a real drawing your builder and your concrete contractor can work from. The design is the part of a radiant job that decides whether you love the floor or fight it, so we would rather do it properly than estimate it.
Can I add radiant floor heat to a house that is already built?
Usually yes. There are three common paths. Heat transfer plates fastened under the subfloor and worked from the basement or crawlspace, which touches nothing in the finished room above. A thin pour over the existing subfloor where the height and the framing allow it. Or an above-floor panel system when there is no access from below. Which one fits depends on access, how much floor height you can give up, and what goes on top.
Does Wahl install electric heated floor mats?
No, and that is a choice rather than a gap in what we carry. Once an electric element is set in thinset under your tile it cannot be serviced, so a failure means taking the floor apart instead of making a repair, and in a shower it also means cutting the waterproofing. A hydronic floor stays serviceable, because everything that wears sits in the mechanical room, and it runs off the boiler that already heats the house. Electric mats do have their place, usually a single small bathroom in a house with no boiler, and in that case we will tell you honestly that we are not the company for that job.
Will a radiant floor also cool the house in the summer?
No. Hydronic heats, it does not cool. In a radiant house, cooling comes from separate equipment, either ductless heads or a ducted system sized for the cooling load. Wahl handles that side too, as a Mitsubishi Diamond Elite contractor, a Bosch cold climate dealer and a Rheem Pro Partner, so the heating and the cooling get designed together with one company.
Does Wahl pour the concrete for a new radiant slab?
No. We prep the floor, set and tie the tubing, and run it out to the manifolds. Your concrete contractor pours, and we coordinate with them directly so the tubing is protected and the pour goes clean. Once the slab is down we come back in to complete the boiler, the manifolds and the controls. On a retrofit there is usually no pour at all, which is a different conversation.
Is a heated floor hot to walk on?
It should not be. A properly designed radiant floor runs warm, not hot, because the entire floor is emitting rather than one small hot spot. Surface temperature is capped by design, and the cap depends on your floor covering. Tile tolerates more than engineered wood does, which is one reason we ask what is going on top before we pick a water temperature.
My boiler is down in the middle of winter. Can Wahl help?
Yes. We run 24/7 emergency service, and hydronic is our own trade rather than something we dabble in. Call (412) 276-9245. We service hydronic and steam systems we did not install, including cast iron radiator systems and steam boilers.
Ready when you are
Call us and get a straight answer. You get the price in writing before the work starts.
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