We need to replace the wall sleeve for our thru the wall heat pump. But ones I see on line won't accommodate our current unit, which is functioning just fine despite being 20 years old. Our current wall sleeve has a smallish rust hole - and has "lips" on each side that the unit sits on. Wall sleeves I see out there now don't have the lips .......sigh.
Any one have any ideas. Could I actually plug the rust hole successfully as someone suggested. Hate to invest in new unit just to replace its metal standard size sleeve!