The Fresh Loaf

A Community of Amateur Bakers and Artisan Bread Enthusiasts.

How to trick a thermostat

LoganK's picture

How to trick a thermostat

I just got a hearthkit, and was very pleased with its inaugural run with a couple pizzas and loaves of pain au levain (margherita was beautifully cooked in about six minutes).  However,  it took much longer than expected to preheat all that mass because the oven kept cycling.  The hearthkit's thermometer got up to the mid 300's relatively quickly, but at that point my oven thermostat, set at 500, started to cycle.  It was well over an hour and a half before it was usable and I never did get it quite as hot as desired.  I'm wondering if anyone has tried to trick their thermostat into leaving the element on continuously until the stone is ready?  Or, can someone recommend a different solution?

thanks a lot, Logan

DerekL's picture

Much longer than expected?  That's actually right in line with what I would have expected.

It's the nature of the thermodynamics involved.  The hearthkit thermometer is measuring the temperature inside the mass, while your oven thermostat is measuring air temp inside the oven.  It takes a long time for the heat to soak into the center of the Hearthkit mass, especially since air has such a low heat capacity.

If you have a convection oven, be sure and preheat in convection mode.  Other than that, it's just a matter of waiting out the time required to heat all that mass.

ericb's picture


I wouldn't advise "tricking" your oven into not cycling. Doing so could create the hazardous situation of heating your oven higher than it was designed to go. There's only so much insulation on your oven.

Something you might want to try, though, is turning on the broiler and leaving the oven door cracked. This way, you will have the full, intense heat of the glowing coils without overheating your oven. Not sure if this will work, but it's worth a try.


JoPi's picture

I was thinking that you might heat the stone on your gas grill.  This is a more direct heat in a smaller space.  Then transfer it to your oven. Might save some on the electric bill.  

phxdog's picture

I have been using a home made, poor man’s hearth-kit made of refractory brick in my conventional oven to bake bread for about a year now. The oven takes a LONG time to come up to temperature (500 degrees F. is as high as I can go), however, using the bricks has made a great improvement in the crust and appearance of the loaves. An added benefit is the residual heat lasts long enough to bake other foods as the oven slowly cools.

Last week I made a few calls to appliance repair and oven parts places looking for advice and possibly a temperature regulator/thermostat that would allow me go as high as 650 degrees in my oven. My reasoning was that my oven, in its self-cleaning mode, reaches VERY high temperatures. Why not try modifying it to allow a higher operating temperature?

The unanimous input I received strongly advised against a modification of this type. Several shops related stories of the numerous home ovens they work on that are damaged simply from the heat of the self-cleaning cycle itself. The wiring of a home oven seems to get fried at these higher temperatures.

So . . . I have resigned myself to using my ‘wanna-be’ brick oven until I become obsessed enough to either construct a backyard brick oven, or bite the bullet and buy a commercial oven. My wife calls me a Bead Junkie.

Scott (Phxdog)

LoganK's picture

Yeah, I was worried that the consensus might be not to mess with it too much.  I like the gas grill idea, but I only have charcoal.  I suspect with fairly direct gas flame you could get the thing roaring hot in at least somewhat less time.  I don't have a convection oven either, so no luck there.   I'll try the broiler next time I bake a hearth loaf and report back.  I don't have a convection oven either, so no luck on that count. 

On the upside, this is supposed to be a cold winter where I live, so at least all that heat lost while the hearthkit preheats and cools down might cut down on my heating gas bill by a few bucks.  I made a gigantic sourdough semolina loaf last night, and in spite of the wait time, the hearthkit did produce a fine product.  I'll just have to start thinking a little farther ahead.

rick.c's picture

You might try turning the oven on to 500 and cracking the door.  It is the same theory as using the broiler, but will be heating the stone via radiation from the bottom element as well.

You *could* also put it in self cleaning mode to heat the stone.  But depending on how long you preheat for, you will be risking the aforementioned overheating issues.  Plus, you would probably have to disable the lock somehow.