hot floor

[Sturgis85]

Don't know where to begin -- who to call.
But we have a tiled house, built in '73, and my wife started noticing that a section of the floor in the kitchen was warm. This area has been growing wider and warmer over the past month, and I'm beginning to suspect someone will have to rip out tile and we'll have to redo the whole house... Obviously, would like to avoid that.

The warm area is near an island, and there is a hot water heater on the diagonal between the heater, hot spot, and sink. There are no obvious problems with the water heater -- nothing I can see -- pipe goes into a wall, no water leaks or unusual water problems...

The island is not electrified. But we do have our more than our share of appliance problems in the kitchen.

I guess the question is: what's a good starting point? what type of person do I call?

[HayZee518]

My thoughts are that the outlet pipe from the hot water heater goes under the floor in the ceiling space where your island is. chances are it isn't insulated against radiating heat from the pipe. the tile is acting as an absorber and radiator. as the water flows through the pipe the pipe is radiating heat which the tile is absorbing and distributing, this is why the area is getting larger. try putting some kraft faced insulation between the floor and the pipe, or a piece of neoprene pipe insulation around the pipe.

[Java_Bob]

I agree with HayZee, but heck the floor may feel good in the winter

[Sturgis85]

Clarification

Hey, thanks for the input. And it does feel good. But I forgot to mention: we live in Florida, and there is no crawlspace or basement, so if there's a pipe under the tile... is it in the cement slab? I don't think there's anything I can look at or get to without removing tiles, and then my wife will want to replace the kitchen, living room, den, hall... (sigh).

[HayZee518]

No crawlspace or nuttin? What a crazy way to build a house - pour a slab and bolt on your bottom plate and build on top of that. if all your water lines are encased in concrete I'd look closely for leaks. portland cement reacts with copper in a direct burial situation. so the tile is installed directly on the slab?? Like I said what a cheap way to build a house BUT I'll bet you paid a pretty penny for it!

[LazyPup]

The pipes are not run in the concrete, they are in the subsoil beneath the concrete.

Normal water usage at a kitchen sink is both intermittent and low volume therefore under normal circumstances it is totally unlikely that the hot water line would radiate enough heat energy to affect the floor temperature. On the other hand, if there happened to be a leak in a hot water line under the floor the flow of water would be constant and could cause a temperature increase such as you describe.

If you are on a municipal water supply there is an easy test to see if you have a water leak. First turn off all faucets in the house and make sure that all toilet tanks are full. You then check the flow indicator on the water meter to see if there is any flow. If the flow indicator is showing a flow when all normal water demands are off the obvious conclusion is that you have a leak. Next, turn the water heater cold water supply valve off and see if that stops the flow. Once again check the water meter to see if turning the water heater supply off stopped the flow. If so, it is almost a certainty that there is a leak in the line under the floor.