EPA Fireplace - Ash Question

I'm a newbie to the EPA fireplaces. I have a Kozy Heat z-41 and the installer mentioned keeping a bed of ash at all times. I also noticed a few posts that mentioned something similar, with one mentioning a 1" bed.

What is the reason for this?

Try it and see - stoves just seem to burn better with some ash remaining. Don't know about 1" or any specific amount, but basically, just don't completely remove all ash from the stove at once or vacuum it up out of every nook and cranny. It's enough to remove ash that's settled in the ash pan and any 'excess' in the bed. And don't overdo it.

I keep a layer of ash in my stove for a couple of reasons . . . 1) as mentioned it acts as an insulator keeping the hearth below the stove a bit cooler and 2) it helps preserve the coals as coals buried in the ash will burn at a slower rate which is handy when you come home several hours later and just need to open up the air and stir the ash to find enough coals to easily ignite some kindling.

The ashes help hold heat around the coals so the wood burns more completely. It's a good insulator.

Indeed ash is an insulator. Mountain men used to carry a hot coal in a leather pouch surrounded by ash which would keep the coal glowing for a considerable amount of time, to make for easy starting of the next fire

+1 to all the above. If you keep ash in the stove, it insulates the coals that lay on the bed of the stove, and it also reflects heat upward (along with the bricks) to keep the core of the stove hot. I always leave at least one to two inches of ash in my stove.

Thanks everyone. This makes sense.