@3beltwesty
Thanks for the explanation. My parents' Hotpoint range (home built 1972) is identical. The manual is long-gone, when you buy a new house with included appliances, you tend to lose the manuals in the flurry of paperwork that accompanies a house sale. We never used any of the timer functions because of the missing manual. They tend to hang on to the manuals when they upgrade or replace an appliance, but this oven came as part of a newly constructed home.
We were aware of the pull-out upper vent, but rarely used it. The vents under the upper oven (above cooking surfaces) seemed more logically placed, unless you plan to burn something in the upper oven. I was not aware that full deployment of the upper vent cuts off venting of the cooking surface vents, not did I realize that partial deployment of the upper vent still draws some air through the cooking surface vents. There is definitely only one fan switch for both of the vents.
What I do know is that about two years ago, I aggressively cleaned the oven inside and out for my folks, and part of that cleaning included inspecting and cleaning (in dishwasher) the vent filters. The two filters above the cooking surface had their share of grime, while the upper vent was nearly spotless---probably due to the fact that it was virtually never used. The coils and trim rings are original and still look ok.
As stated above, I recently visited the neighbors and noted they have a 30" standard electric range, with taller cabinets above range plus a hood. Since this was a 300 unit condo development, buyers must have been able to elect either of the two ovens (my guess is the double oven Hotpoint was at extra cost) and the cabinet maker then supplied either short or standard overhead cabinets to fit (the neighbors have the same model and same kitchen layout, in a reverse mirror of my parents' kitchen).
Other than at Thanksgiving or Christmas, my parents rarely used both ovens at once. I was in high school when they bought the condo (downsizing from "the big house"), mostly because their gardening crew (their kids) was about to ship off for college and they no longer needed all the room or the yard.
Within two years of purchase, they were empty nesters, and for most purposes the upper oven is all they need. Roasting a chicken, occasionally baking, etc. The upper oven is manual clean, the lower is self clean, but they distrusted the process of raising a heat shield and then locking the oven with the lever, so they never used the feature and always cleaned it manually. The smaller upper oven is easier to clean, anyway. Because the lower oven has a crack in the glass, they use it for warming functions but not at high temperatures (no one is sure how the crack gone there, whether it was trauma or high temperatures).
The range in their kitchen is original. In terms of dishwashers, the original was a matching Hotpoint that died only three years after installation. A replacement GE lasted about 24 years. Now they have a KitchenAid with about six years on it and doing well. They are also on frig #3. First was a side by side yellow Gibson. Replaced about ten years later by a GE side by side with dispenser door which soldiered on until about six years ago, and now they have a GE Profile side by side. First set of washers were Hotpoints, replaced about ten years later with GE's, now they've had a set of Maytags for about eight years (top loader).
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