# Infloor Radiant Heat



## 06Honda (Feb 4, 2017)

I own a one level home on slab and is fairly open throught with 2 zones of infloor radiant heated via a gas fired hot water tank. One zone is usually set to 21 C or 70, the other anywhere from 18-19 C or 64 - 66 F. When I feel the floors that aren't warm but feel more neutral overall. If it is really cold out and I turn up both zones higher then after a while the floors do feel warm. Is a neutral feeling for the floors meaning not hot or cold seem correct for how this system should work. Floor surface materials are vinyl; ceramic tile, & wood.


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## Gary (Feb 4, 2017)

If the room temps stay where the thermostat is set I'd say it's working the way it's supposed to. I have some radiant heat, although not in a slab, and the floor feels neutral on all but on the coldest days, then I can feel some heat. Without the radiant heat they feel ice cold.


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## slownsteady (Feb 4, 2017)

Feeling neutral should indicate that the temp is close to body temp or at least the same temp as the room. so that is a good thing I imagine.


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## 06Honda (Feb 4, 2017)

Sounds good, thanks for the input and post backs. I noticed that the new tank we just had installed a few days back was set to 120 so I have bumped it up to 125. The plumber who installed left it at 135 but i turned it down when he left but maybe i turned it down too much?


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## beachguy005 (Feb 4, 2017)

I'm assuming you have in slab, rather than on slab, radiant heat.  The slab acts as a huge heat sink but takes a fair amount of time to heat up.  When you stat calls for heat, hot water is pumped through the slab heating it which then heats the flooring on it.  Then the space heats up.  Once the temp your stat is set to is reached, no more hot water is circulated. While the floor may no longer feel warm, it has heated not only the flooring but radiated into anything in contact with the floor.
You will feel some fluctuation in the temp of the floor.


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## 06Honda (Feb 4, 2017)

Thanks for the explanation beachguy005


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## slownsteady (Feb 4, 2017)

I'm not all that familiar with in-floor heat, so let me ask: Is the tank part of the heating system, or does the boiler feed the floor directly. I imagined the OP was talking about a hot water tank for...well...hot water.


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## beachguy005 (Feb 5, 2017)

Typically the in slab and the water heater use the same boiler but they are separate water sources.  The heated water from the boiler is used to heat the floors and circulated through the water tank to heat the domestic hot water.


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## bud16415 (Feb 5, 2017)

We heated my nephews house this way and used a regular 40 gallon gas fired hot water tank. We set the house up for three of them but only ever needed two. One for domestic hot water and one for heating. So it could be a regular water heater.

The one problem is the thermal mass. Come spring and fall when you get a cold night it takes all night to warm the mass then the next morning it warms up outside and you cook. 

It is wonderful in a heated garage when you get down on the floor it is so warm you fall asleep under your truck.


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## slownsteady (Feb 5, 2017)

Yep, same boiler. But the hot water tank has no direct connection to the heat, if I understand correctly. That's what I figured. It wouldn't make sense to heat a tank of water in order to supply a relatively small amount of water in the floor. 
The water heater may have it's own zone valve on the boiler or it may be self-contained.


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