Woodstock progress hybrid The temp on top of the stove versus the cook top

[fespo]

Hello everyone, I thought of this idea yesterday as I was waiting for my stove to heat up before I engage the cat. The temp on top of the stove versus the cook top. Of course the cook top (no stones) is much hotter so I should be able to engage it earlier then waiting for the stones to heat up to the correct temp? What do you think? Fespo

 

[Rearscreen]

My thermometer is to the rear of the left stone on the cast iron as the center stone is usually flipped up. If I move the thermometer to the center part of the cook top, the temperature is much higher. Could I engage the cat sooner based on the higher reading? Maybe, maybe not. From experience, where the gauge is now, 300 is the time to engage. At 250 it just doesn't seem to kick it off. If you wait for the stones to heat up, there is a possibility that you could engage it earlier as the stone is insulating the heat within and maybe giving you a lower reading.

 

[fire_man]

It seems to totally depend how old is the Combustor. A brand new one allows me to engage when the flue cover plate hits 250F even though stonetop temp may be MUCH lower. As the Combustor ages I have to wait for higher cover plate temps. But in either case WS recommends in their manual using stove pipe or cover plate temps.

We recommend placing the thermometer 8”-10”above the flue collar on single wall stove pipe if the stove is vented out the top.

If the stove is rear vented, the surface thermometer should be placed on the cast iron cover plate toward the back of the stove.

If you are reading the single wall stove pipe temperature, the interior flue exhaust temperature is about twice as hot. Since the 22 gauge sheet metal pipe is more reactive (faster heat transfer) than the stove top, you will find you can engage the combustor sooner. We recommend engaging your catalytic combustor once the pipe thermometer reaches 300°-350° F. Stove top temperatures should reach approximately 250°F.

 

[Woody Stover]

Keystone, not PH, but I have the "cat probe" that comes in from the back, off to the side of the rear-exit flue opening. It gives the flue exit temp, more than the actual cat temp. I will run that up around 1000, then cut the air to hold there for about 10-15 min. as the load burns in a little more. A surface meter lying on top of the tee snout will be 450-500, which sounds about right (1/2.). At that time I can close the bypass and light off, even though the stove top over the cat isn't anywhere near the 250 they suggest...more like 150 or less. I never shot the top flue exit plate under the stone but I bet it would be maybe 400 more or less. I'll do that when I load up..