Thanks for the many responses. To answer a few of the questions:

1. ">Is the tile against the ovens thermometer/sensor?" No, the tiles are
on the bottom shelf of the oven, just above the bottom heating element, and
the sensor is toward the top of the oven.

2. >Are you getting excellent bread?" Absolutely! (if I may say so myself).
But of course we use the oven for all kinds of other things, too, and many
of them need relatively accurate cooking temperatures. I suppose I could put
the tiles in only when baking bread, but I've read of many people just
leaving them in and never heard of this problem before.

3. >"Can you place your thermometer next to the sensor?" The sensor and the
thermometer are within an inch or so of each other. So this doesn't appear
to be caused by temperature gradients within the oven or a convection
problem.

4. >"Did the oven manufacturer recommended that tiles be put into the oven?"
Not as far as I know. The oven (Magic Chef, now owned by Maytag) was here
when we bought the house, and I haven't found any indication one way or the
other. But as I mentioned, I've read of many people doing this -
particularly bread bakers - and haven't heard of any problems.

5. >"How long is the oven on when you are noticing the temperature
difference?" 45 minutes or more. Once the oven gets up to temp, both
readings are stable and the difference doesn't change.

So here I am, still wondering which reading to believe. I am tempted to
believe the Taylor, since it's known for its accuracy, and to assume that
some weird phenomenon is throwing off the oven sensor. It's a shame, really,
because the convenience of having an accurate sensor means we don't have to
open the oven, check the thermometer, adjust the temp, check again, etc.


"Sidney" > wrote in message
news:BgYIb.97393$pY.4662@fed1read04...
> Is the tile against the ovens thermometer/sensor? If so, the oven may be
> "cutting off" prematurely due to the oven's sensor reaching the desired
> temperature on the side of the tile next to the heating element and oven's
> thermometer. If you move the tile away from the temperature sensor in the
> oven, it should stay "on" until the whole thing is up to temperature, not
> just on one side of a single tile.
>
> Sid
>
> "Peter Cook" > wrote in message
> hlink.net...
> > Anyone encounter this? My electric oven is lined with quarry tiles since
I
> > bake a lot of bread. I use a Taylor thermometer to measure the temp, and
> > when the tiles are in the oven, the thermometer reads significantly
lower
> > than the oven's digital readout after preheating. At lower temperatures
> > (300), the difference is about 60 degrees. At higher temperatures (475),
> > it's about 25 degrees.
> >
> > When the tiles are removed, the readout and the thermometer are within 3
> or
> > 4 degrees. I keep the thermometer close to the oven's temperature
sensor,
> so
> > they are measuring temperature at the same location in the oven.
> >
> > All readings are taken after the oven has preheated for at least 45
> minutes.
> >
> > Obviously the heating characteristics of an oven change when there are
> tiles
> > involved. But why would they cause the thermometer and the oven's
> > temperature sensor to behave differently? And most importantly -- which
> one
> > is right??
> >
> > Pete
> >
> >
> >
> >
>
>