Hydronic in floor heating warms a room by circulating warm water through tubing set in or under
the floor, so the floor itself becomes the radiator. It is the most comfortable heat available in a
Calgary winter, it runs at a low water temperature, and it is quiet, because there is no blower and
no ductwork. 180 Plumbing and Heating installs, services and repairs hydronic in floor systems
across southeast Calgary: basements, bathrooms, garages, additions and whole homes. Red
Seal Journeyman Plumber and Certified Type B Gasfitter. Call 403-404-9975.
How it actually works
Warm water runs through flexible tubing laid in loops. The loops connect back to a manifold, and
the manifold connects to a heat source, usually a boiler or a combination appliance with a boiler
built into it.
The water is not hot. A radiator might run at 70C or more, but a floor is a very large radiating
surface, so it only needs water at a much lower temperature to deliver the same heat into the room.
That low operating temperature is the reason in floor heating is efficient, and it is why it pairs
so well with a condensing boiler, which is at its most efficient when the water coming back to it
is cool.
The floor holds heat, which means the system responds slowly and then stays steady. You do not turn
in floor heating up and down the way you flick a furnace on. You set it and it holds.
Where it makes sense in a Calgary house
Basements. The single most common request we get, and the one that changes how a house is used.
A basement floor sits on ground that stays cold all year, which is why a basement can feel cold
even when the thermostat upstairs is satisfied. Heating the slab fixes the cause instead of blowing
warm air at the symptom.
Bathrooms. The smallest, cheapest and most appreciated version. A warm tile floor on a January
morning is the upgrade people mention to their friends.
Garages and workshops. A radiant slab beats a hanging heater for anyone who actually uses the
space. It warms the floor, the tools and the car rather than the air near the ceiling, and it does
not blow dust around a workspace.
Additions and bonus rooms. Rooms at the end of a duct run are often the coldest in the house
because the air has travelled too far to get there. In floor heating gives that room its own heat
source and its own control.
Whole homes. Usually in new construction or a full renovation, often alongside a duct system
for cooling and ventilation.
What we install
In a new slab. Tubing is fastened down before the concrete pour, so the loops end up inside the
slab. This is the best version: the whole slab becomes a low temperature radiator with a lot of
thermal mass.
Over an existing floor. Panel systems that carry the tubing sit on top of the existing
subfloor, with the finished floor over them. This adds height, which has to be planned around
doors, stairs and cabinets.
Under an existing floor. Tubing run between the joists from below, insulated underneath so the
heat goes up. This is the option when you cannot raise the floor or take up the finish, and it is
the usual answer for an upper storey with an accessible basement ceiling.
Zoning and controls. Each area gets its own loop or set of loops, its own thermostat and its
own control at the manifold. A bathroom that wants to be warm at 6am and a basement that wants a
steady 20C are two different jobs, and they should not be on one switch.
The heat source. A dedicated boiler, or a combination appliance with hydronic capability built
in. If you have a Gradient syncFURNACE Boiler, the boiler and the pumps are already inside the
appliance, which removes most of the mechanical room work. See
the syncFURNACE Boiler. A Gradient GCx is the wall hung option
when floor space is tight. See the GCx.
What we repair
Existing in floor systems fail in a small number of predictable ways, and most of them are fixable
without touching the floor.
- A zone that has gone cold. Usually a circulator pump, a zone valve or an actuator, all of
which live at the manifold rather than in the floor. - Air in the loops. Air collects at the high points and stops flow. Purging the system properly
is a routine job and it fixes a surprising number of “the heating is broken” calls. - Falling system pressure. Something is losing water. The cause is worth finding, because
repeatedly topping up introduces fresh oxygenated water, which is harder on the system than the
original fill. - A failed mixing valve or control. The system is either sending water that is too hot for the
floor or not hot enough to heat the room. - A boiler that will not fire or keeps locking out. That is a boiler problem, not a floor
problem. See boiler repairs. - Scale and water quality. Calgary water is hard, and hard water is as unkind to a boiler heat
exchanger as it is to a kettle.
Almost nothing goes wrong inside the floor itself. Modern tubing is durable and the loops are
continuous, with no joints buried in concrete. When someone tells you the tubing has failed, ask
what evidence there is, because the answer is usually at the manifold.
Running costs, honestly
In floor heating is efficient for two reasons that are both real: it runs at a low water
temperature, which suits a condensing boiler, and it heats the surfaces in a room rather than the
air, so people are comfortable at a lower air temperature than they would be with forced air.
What it is not is free heat. A heated basement slab is heating a space that was previously
unheated, and heating more of your house costs more than heating less of it. The comfort is worth
it to almost everybody who does it, but we are not going to pretend the gas bill goes down when you
add a heated garage.
We will give you an honest view for your specific house, including whether a smaller version of the
project gets you most of the benefit.
What we will tell you before you commit
Floor height matters. Over floor systems add height. That affects doors, stair risers,
appliance openings and transitions. It is solvable and it is much easier to solve before the work
starts.
Insulation under the slab is not optional. Heat goes in every direction, and without insulation
underneath, a good share of what you pay for goes into the ground. If we are pouring a new slab we
insulate it. If we are working over an existing uninsulated slab, we will tell you what that costs
you in the long run.
Response time is a feature, not a fault. A concrete slab takes hours to come up to temperature
and hours to cool. If you want a room that goes from cold to warm in twenty minutes, in floor is
the wrong tool for that room.
Some floor finishes suit it better than others. Tile and stone are ideal. Engineered wood is
usually fine within the manufacturer’s temperature limits. Thick carpet and heavy underlay work
against you. Check the flooring manufacturer’s instructions, and if you are choosing the floor at
the same time, choose it knowing this.
Booking it
We install and service hydronic in floor heating across southeast Calgary. Call
403-404-9975.
What is free
- A written quote, yours to keep whether you use us or not.
- An in home water hardness test. Relevant here because water quality affects the life of every
hydronic heat source in this city.
How we price this work
We charge by the job, not by the hour. Hourly billing punishes you when a job turns out to be
complicated and punishes us for being quick, so we price the job. You get one number for the
finished work, agreed before anything starts and always in writing. Parts, labour, disposal and
permits are in the number you agreed. If we find something else once we are in, we stop and
re-quote, and you decide.
On a project this size you will see three options rather than one: the straightforward version, the
one we would recommend, and the one that does the whole job properly. We will tell you which one we
would choose in our own house.
Frequently asked questions
Is in floor heating expensive to run in Calgary?
It is efficient for two reasons: it runs at a low water temperature, which is where a condensing boiler is at its best, and it warms surfaces rather than air, so people are comfortable at a lower air temperature. It is not free heat, though. Heating a previously unheated basement or garage adds heated area, and that costs more than not heating it.
Can I add in floor heating to an existing house?
Yes, in three ways. Panels over the existing subfloor with the finished floor on top, which adds height. Tubing run between the joists from below, which suits an upper floor with an accessible basement ceiling. Or in a new slab, if you are pouring one for a basement, garage or addition.
How long does in floor heating take to warm up?
Hours rather than minutes, particularly in a concrete slab, and it holds its temperature for hours afterwards. That is how it is meant to work. It is set and left, not turned up and down, and it is the wrong choice for a room you want to heat quickly and occasionally.
What heats the water for in floor heating?
A boiler, or a combination appliance with a boiler built in. If you have a Gradient syncFURNACE Boiler, the boiler, the pump and the mixing valve are already inside the cabinet. A wall hung condensing boiler such as the Gradient GCx is the option when floor space is tight.
One of my in floor zones has gone cold. What is wrong?
Usually something at the manifold rather than in the floor: a circulator pump, a zone valve, an actuator, or air trapped in the loop. Falling system pressure and a failed mixing valve are the other common causes. Very little goes wrong inside the floor itself, because the loops are continuous with no buried joints.
Can you put in floor heating under any flooring?
Tile and stone are ideal. Engineered wood is usually fine within the flooring manufacturer’s temperature limit. Thick carpet and heavy underlay insulate the floor from the room, which works against the system. Always check the flooring manufacturer’s instructions.
Written by Desmond Neufeld, Red Seal Journeyman Plumber and Certified Type B Gasfitter. Last updated 23 August 2026.
