It used to be that toilets lower than the drain pipe were set on a raised platform, usually concrete, so gravity could help with the flush.

We had a bathroom added to the basement in 2005. I asked the contactor about that and he said the new toilets were designed to work without the platform. We've never had trouble with that toilet.

My house is a pre-war house, built right before WW2 (1940).

I do know someone with a basement apartment and they have a toilet with a built-in in injector pump that flushes with out having to be on a raised platform like the old school ones. It has a box with the injector pump mounted in back just below the tank.

While a normal toilet uses a tank full of water and gravity to flush, these pressure assist toilets have a small tank inside the tank in place of water. This small tank is similar to the tank in a private well pump. It has a rubber diaphragm in the middle of the tank. The water line feeding the toilet connects to the bottom of the tank and the water pressure pushes up on the diaphragm compressing the air in the upper part of the tank. When you push the flush lever it release the pressurized air and it flushes like a toilet in a commercial building. They are sold at Home Depot and yoi can even have Home Depot install it. It might be cheaper than having your plumber do it.

The second suggestion is to have a bottle or two of this product called Green Gobbler on hand. It can be bought st places like Walmart and Home Depot or ordered on Amazon.
https://www.walmart.com/ip/14691219721?sid=4af2d9ce-eb5c-4a34-9a94-a29886baa693
It is a heavy green liquid that you put into your toiled that clears clogs. It is like a specialized Drano (never put Drano in your toilet) for the toilet. Follow the direction and give it time to work.

I really feel that, at my age, it is that we pay good money for a professionally well done job so how it can not work just minutes after the plumber left just makes me crazy...

Several years ago. It has two bathrooms. The toilet that were installed are older but still available. They are $500 toilets. I would never spend $500 on a toilet. I have never had more flushing problems than I've had here. I'm older (65) and my bathroom habits and toilet paper usage might have changed.
It could be that the drain pipe that the toilet is connected to has become partial clogged over the years and that night have to be "snaked out". I end up having to regularly use a plunger on at least one of them.

So even more than any cost, its he damn inconvenience and panic of not being able to flush toilet.

However that Green Gobbler stuff really works. It's nearly $20 a bottle but you get three uses out of the bottle. You can even add it once in awhile as preventive maintenance.

Your post actually gave me a kick in my procrastinating back side to go to Home Depot and shop for one those pressure assist toilets for the main bathroom. I had one in my house in MA and it never clogged

I believe it is this toilet, or this is a newer version of it.


Strong Flush and Comfortable Height https://www.amazon.com/vdp/02ed25dd6e654e14a4df92806433d28c?ref=ive_share_mshop_detail

I won't bombard you with any more links. That one is from the manufacturer. The toilet is also sold at Home Depot. When you flush it it is like a "turbo flush" it flushes with a loud whoosh noise. We had three daughters and I dont think it ever clogged. I'm going to a visit my local home depot to see if they have one. I sse on tge link to it at my home depot there is a $75 rebate from the local water utility.

I've become convinced it's actually a portal to hell. I hope your demons didn't come out of my closet.