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  #1  
Old 10-13-2009, 01:24 AM
MaxTheVool MaxTheVool is online now
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Warm spot under the house floor

A few days ago, my wife noticed that there's a big warm spot under the tile floor of our entry hallway and kitchen. Also, our cold water tap sometimes runs warm, presumably because the pipes go through this warm spot, so the water is heated up (if you let them run, it cools back down, presumably because it was only the water that stayed there for a while that heated up).


How concerned should we be about this? Does this ring any bells with anyone?


thanks
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  #2  
Old 10-13-2009, 02:15 AM
cmyk cmyk is offline
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The hot water pipe itself?

Duct work directly under that spot?

A light fixture in the basement?

An electrical problem?

Animals living under the floor?

Radon gas?*

Ghosts?!

*kidding.

Last edited by cmyk; 10-13-2009 at 02:16 AM..
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  #3  
Old 10-13-2009, 03:21 AM
FloatyGimpy FloatyGimpy is offline
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That happened at my grandma's house and it ended up being a burst pipe shooting hot water on the the floor.
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Old 10-13-2009, 05:59 AM
ZenBeam ZenBeam is offline
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We have warm lines on the floor, above the ductwork that runs to the heating vents. Also, when we had our basement finished, a duct was run between the same pair of joists that had a large water line, o we get warm water from our cold faucet in winter (for a short time).

Can you go down a floor and look up? If not, you could try to correlate the heating vents to the warm spot.
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  #5  
Old 10-13-2009, 07:44 AM
Quercus Quercus is offline
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What kind of heat do you have? And do you notice the warm spot only when the heat is on?

We've got warm spots from the steam heat pipes running under the floor. In my fantasy world, one day I'll re-route the pipes so they run under the floor between the bathroom and the bed where the warm spot would be useful.
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Old 10-13-2009, 07:55 AM
LSLGuy LSLGuy is offline
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You're not near Yellowstone are you? I'd sure hate to find a supervolcano breaking through my entryway floor.
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  #7  
Old 10-13-2009, 08:04 AM
Sailboat Sailboat is offline
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Make sure it's not a furnace fire. When I was a toddler, I found a hot spot on my bedroom floor and tiny wisps of smoke coming through a knothole and woke my parents to tell them. It turned out to be a fire out of control in the furnace in the basement (I'm not clear on whether the basement itself had caught fire or the walls of the furnace unit or what; I was pretty young at the time).

Everyone but me was asleep and the fire was underneath the kids' bedroom.
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  #8  
Old 10-13-2009, 08:09 AM
Zsofia Zsofia is offline
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That's not where the dog likes to sleep, is it? Sometimes it's the simplest explanation.
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  #9  
Old 10-13-2009, 08:28 AM
johnpost johnpost is online now
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a long shot.

floor tiles can hold a lot of heat, does that spot get major sunlight during the day.
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  #10  
Old 10-13-2009, 09:24 AM
The Great Sun Jester The Great Sun Jester is offline
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I have the same thing in my living room.

* There are no water pipes near the spot.
* There is a forced air duct that runs near the spot but the warmness is confined to about a 3 foot diameter spot, not the length of a duct, and it's warm even when the AC is running.
* There is a light fixture near the spot (for the room below) but the spot is warm even when the light hasn't been on.
* We don't have a dog.

Probably some kind of radioactive decay.
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  #11  
Old 10-13-2009, 09:34 AM
Tastes of Chocolate Tastes of Chocolate is offline
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Quote:
Originally Posted by Quercus View Post
We've got warm spots from the steam heat pipes running under the floor. In my fantasy world, one day I'll re-route the pipes so they run under the floor between the bathroom and the bed where the warm spot would be useful.
The house I grew up in had a seperate tub and shower in the bathroom. The hot water pipe ran under the tub to get to the shower. It wasn't uncommon to walk by the bathroom in the morning and see someone standing in the empty bathtub, brushing their teeth.
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  #12  
Old 10-13-2009, 10:58 AM
cjepson cjepson is offline
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We had the exact same problem that you describe. It was a water leak in our heating system. (Our house is on a concrete slab, and we had baseboard heating; the baseboards were fed by pipes that ran under the slab. Of course, the warm spot appeared only during heating season.)

If your problem is a leaky pipe, the difficulty of fixing it will depend on the type of pipe. IIRC, copper pipe can be fixed pretty easily, but if it's galvanized pipe, the entire section of pipe has to be replaced.

We ultimately decided just to get a new heating system so that we wouldn't have to worry about future leaks. (We had been thinking about doing that anyway, and fortunately were in a position to do so.)

Our water bill is now a LOT lower.

Last edited by cjepson; 10-13-2009 at 10:59 AM..
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  #13  
Old 10-13-2009, 11:23 AM
MaxTheVool MaxTheVool is online now
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It's in the ground floor, and there's no basement. And we have no central heating at all (being in California).

The only thing in the house that heats things, as far as I know, is the hot water heater. It seems not to be leaking, nor does it seem (based on the naive listening approach) to be running at all.

It's certainly not just where the dogs are lying, that wouldn't turn cold water hot.


My theory is that maybe the neighbor's hot water heater is leaking? (It's a townhouse, so right up against houses on both sides).
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  #14  
Old 10-13-2009, 11:27 AM
Sunspace Sunspace is offline
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Just to be sure... you do NOT have radiant heating in the slab? The kind with hot-water pipes that circulate water through the slab comes to mind.
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  #15  
Old 10-13-2009, 02:32 PM
pojimba pojimba is offline
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I was gonna say your clothes dryer wasn't vented properly; been there and done that.
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Old 10-13-2009, 04:26 PM
MaxTheVool MaxTheVool is online now
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Quote:
Originally Posted by Sunspace View Post
Just to be sure... you do NOT have radiant heating in the slab? The kind with hot-water pipes that circulate water through the slab comes to mind.
Unless I've had it for 4 years without being aware of it and it just now has suddenly gotten turned on. Stranger things have happened, but it seems unlikely.

Quote:
Originally Posted by pojimba
I was gonna say your clothes dryer wasn't vented properly; been there and done that.
Presumably that would only happen while the dryer was running?
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  #17  
Old 10-13-2009, 04:32 PM
Chronos Chronos is offline
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That's not where the dog likes to sleep, is it? Sometimes it's the simplest explanation.
Mind your cause and effect... All the animals I've lived with in my mom's house loved sleeping on the spot directly above the furnace, since that was the warmest spot on the floor. Unfortunately, that spot was also right directly in the doorway between the kitchen and the dining room, the most traveled route in the house, so you always had to watch your step.
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  #18  
Old 10-13-2009, 05:00 PM
Arnold Winkelried Arnold Winkelried is offline
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Do you sometimes hear a sound coming from that area? A low, dull, quick, sound - much such a sound as a watch makes when enveloped in cotton? If so there might be a BEATING HEART under your floor!
(apologies to E.A.P.)
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  #19  
Old 10-13-2009, 05:08 PM
hermann hermann is offline
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If you are on your own water meter, look at it to see if the "tattletale" is moving. Of course, you should make sure nobody uses the water while you're doing this.
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  #20  
Old 10-13-2009, 06:27 PM
sideshowkar sideshowkar is offline
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I had something similar a few years ago. It turned out to be a slab leak - just a minuscule little hole in one of the pipes under my concrete slab.

I probably had it for a few months, but there was hardly any water leaking out, so I didn't notice it. I did smell something like mildew every time I came home from work though, but I couldn't figure out what it was. Then one of my cats started sleeping right over the spot, which was odd for her - she prefers the bed to the floor. I thought it was because it was the wall next to the water heater, but then I realized she wasn't right up against the wall, so I felt the floor and noticed it was warm. Then I realized my hand was a little damp.

This one little thing made my life a nightmare for about 3 months. Even though the leak was really small, almost all of the carpet in my 1000 sq ft house turned out to be wet. The padding underneath is like a sponge. I ended up getting rid of all of it and had my concrete slab polished... which turned out to be really good when the water heater sprung a leak... And because I just have the slab as my floor, I can totally feel a bunch of warm spots now, but I know they're just hot water pipes.

When I was getting it taken care of, the plummer told me that a good way to test for a leak is to put something plastic over the spot and leave it for a few days. If there's a leak, water will condense underneath it. This was something I'd already noticed - I had a bunch of plastic bins under my bed and those were the spots that were soaked when everywhere else was just a bit damp. I don't know how it will work with tile, though, but good luck.
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  #21  
Old 10-13-2009, 06:33 PM
Tastes of Chocolate Tastes of Chocolate is offline
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Quote:
Originally Posted by MaxTheVool View Post
Also, our cold water tap sometimes runs warm, presumably because the pipes go through this warm spot, so the water is heated up (if you let them run, it cools back down, presumably because it was only the water that stayed there for a while that heated up).
The 2 aren't necessarily related. You don't mention how warm the water is. I get something similar with my cold water. In my case, it's the fact that there are runs of cold water pipes in the walls, between where the water comes into the house and the faucets. The water in these pipes, when it sits, warms up to room temp. When I turn on the cold water tap, the water feels warm, until the pipes are emptied, and when I start getting water that was shortly before in the water main, it is much cooler.
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  #22  
Old 10-13-2009, 11:55 PM
MaxTheVool MaxTheVool is online now
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Quote:
Originally Posted by Tastes of Chocolate View Post
The 2 aren't necessarily related. You don't mention how warm the water is. I get something similar with my cold water. In my case, it's the fact that there are runs of cold water pipes in the walls, between where the water comes into the house and the faucets. The water in these pipes, when it sits, warms up to room temp. When I turn on the cold water tap, the water feels warm, until the pipes are emptied, and when I start getting water that was shortly before in the water main, it is much cooler.
Except that I've lived in this house for 4 years and this has never happened before now, so it seems nearly certainly related
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  #23  
Old 10-14-2009, 02:16 AM
Magiver Magiver is online now
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Quote:
Originally Posted by MaxTheVool View Post
Except that I've lived in this house for 4 years and this has never happened before now, so it seems nearly certainly related
Do you have a slab or a crawl space? If it's a crawl space could you have heat tape on your pipes in case they freeze? That could be stuck on.
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  #24  
Old 10-14-2009, 09:06 AM
pan1 pan1 is offline
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Has anyone been to the crawlspace to check it out?

Where in California are you. Is geothermal activity a possibility? Do you know of any Hot Springs nearby?
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  #25  
Old 10-14-2009, 09:08 AM
pan1 pan1 is offline
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I don't think I've seen this asked -

Do any windows put sunlight on the area for an extended period of time, particularly any windows with any lensing effect?
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  #26  
Old 10-14-2009, 11:38 AM
MaxTheVool MaxTheVool is online now
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So we had the leak detection people out this morning, and it's a leaky pipe under the slab (no crawl space). Fixing it will require jackhammering the slab. So another $750 on top of the $250 to find it. Ah well.
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  #27  
Old 10-14-2009, 04:25 PM
carnivorousplant carnivorousplant is online now
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I had a leak in the slab repaired for much less by a plumber who works for himself. There may of course by licenses and permits involved for you, but it may be worth checking out. He chiseled the pipe out of the slab.
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