The Amana oven ignitor failed. Of course you only notice that when you are about to use it. Fortunately it was something that just needed heated, not a cake or something that really needed “Bake” at “xx0” for “whatever”. We just ran the “Broil” to get the oven and the food hot. But the ignitor for the bake part still needed replacing.
Get the oven model and serial number. On this stove, they are located on the left oven frame, inside the bottom drawer. Then obtain the ignitor. In Greenville, I go to G+E Appliance Parts(closed Saturday. Banks is open until noon on Saturday) but you can get parts on-line if you have time to wait.
The ignitor is fragile. Open the box carefully ensuring that as you unwrap the layers of corrugated board that the new ignitor is always on the bottom. When it is visible, handle it carefully by the ceramic part only. Never touch the heat bar part.
Unplug or disconnect the stove or turn off the breaker. Verify that that the oven light goes out. Remove the oven wire shelves. Remove the bottom burner cover by lifting and sliding forward to release the tabs at the rear.
You will see the guard over the ignitor at the rear of the oven next to the burner tube. Remove 1 screw at the burner and 2 screws
against the back of the oven floor. Your oven may be different. The sheet that comes with the ignitor shows some variations. Pull the guard toward the front of the oven. The ignitor will come with it. Continue to pull carefully drawing the wires out until the wire-nut connectors appear. Unscrew the wire-nuts and disconnect the ignitor.
With the guard and ignitor out of the oven remove the guard from the old ignitor and slide it on the new ignitor until it hits the stop. Re-attach the stove wires with the wire-nuts. Stuff the wire and wire-nuts back into the hole, making sure that they go down the hole and outside the bottom of the oven. Re-position the guard and replace the 3 screws.
Re-connect the power. Test by turning the oven to Bake and an aribtrary temperature. The ignitor should glow white-hot within a few seconds. A bit later, the gas will come on and it should ignite. If this test fails, turn off the oven controls and investigate with the power off and gas off.
If the test is successful, replace the burner cover with tabs in the rear engaging the slots in the rear of the oven floor. Replace the wire racks.
I presume replacement of the boiler ignitor is similar. It gets used much less and I have not had to replace it.