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PJx
 
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Default Radiant Heat in Slab -- HELP!

On Wed, 4 Feb 2004 08:11:28 -0700, "SQLit"
wrote:


"Tom Newton" wrote in message
...
Hi Folks -

I live in NY where it's cold, and I have a question here that I'm

literally
afraid to ask. I have a contractor doing a new kitchen for me and he's
almost done and has 80% of his money. The kitchen is 12'x17' and, unlike

the
rest of the house, sits on a slab extension out back (there's a full
basement under the main footprint of the house, which is 90 years old, and
this kitchen extension is an appendage off the rear).

The extension was actually pre-existing from about ten years ago when the
previous owner put in a laundry room and a few walk in storage rooms

there.
Anyway, my goal was to have the entire area over the slab gutted (12x17)

and
make it our new kitchen, with ceramic tile floors, and have radiant heat.

Here's the deal... we're almost done, the contractor put in the radiant

heat
tubing long ago, laid the tile done weeks ago (but never hooked up the
heating system to the boiler till now) and has continued to build the
kitchen and is almost done with everything.

But yesterday, they finally hooked up the radiant heat to the boiler, and
there is bad news. After running it for two hours at 180 degrees the damn
floor is still cold... and the return water is barely luke warm!

snipped

If the water going out is 180 and is barely warm coming back then I would
say that it is working. This is not forced air. No instant gratification
here. Keep the pump running to the floor for 24 hours, it will take some
time for the slab, tile and everything to warm up. You said it was cold
outside....



He says 24 hours. I say 48 hours minimum and preferably 72 hours
before you even put a thermometer to it. And that might not be long
enough.

In two hours, the system has not even started to stabilize. Give it
72 hours running full steam and report back to us.

PJ