LPolk and Jerry, thanks for your comments. I've had adventures in vapor steam cleaning since I first posted my query. A nice lady from Norwalk, CT came to my house and demonstrated the wonders of the Ladybug XL, which I did order from her. I think the on-site demonstration is very helpful, because there are definitely a few things to learn about how to use these things, and the hands-on demonstration helps. There's a video that comes along with the machine, too. Since I am of the opinion that one might as well be hung for a sheep as for a lamb, and since I have few other major vices besides my addiction to high-end home appliances, I bought some fun accessories as well: the (terrific) steam iron that can be run off the Ladybug, and the aromatherapy attachment (after cleaning the kitchen you can infuse the air with a favorite essential oil, like peppermint, or bergamot). I am enjoying the Ladybug very much -- it has added a couple of years to the lifespan of child- and dog-worn living room upholstery, and revived outdoor furniture cushions that I thought were beyond the pale, and I use it on all the rugs in the house, including some old vegetable-dyed Orientals -- they are significantly brighter and silkier/springier afterwards, and I don't see pigment coming out of the old rugs onto the terry towel that wraps the cleaning head, just dirt. I can clean my entire bathroom (limestone, stainless steel, porcelain, glass, and polyurethaned wooden floor) without using any solvents or paper towels -- the very hot vapor sterilizes surfaces. Afterwards, I wash any dirty terry towel wraps in a hot-water wash, dry them, and they're ready to reuse. I bought the cleaner because I wanted to be able to steam-clean mattresses to kill dust mites, to which my mildly asthmatic son is allerlgic. There is medical research that shows that vapor steam cleaning does significantly reduce the amount of dust mite and dust mite antigen on rugs and mattresses -- you have to follow the steam cleaning with a good vacuum with a HEPA filter to remove the dead mites and their residua -- but I haven't yet come across any medical literature that proves that this leads to significant improvement in clinical symptoms for those who are allergic to dust mites -- so it's too soon to make that claim. Still, I feel very virtuous as I steam clean the mattresses and pillows. The Ladybug can wash windows -- or i should say, YOU can wash windows using the Ladybug. There are other attachments like the "tough kit" for cleaning grills, or detailing the car, but I haven't done either of those tasks yet. I do clean my kitchen range, and that is deeply satisfying. In general, the Ladybug is a great tool in the kitchen. In fact, the hardest part is deciding where to keep it: near the bathrooms, or in the laundry room with the ironing board, or in the kitchen? I think the continuous refill feature is very important, because in the course of several hours of steam cleaning one might need to top up the reservoir at least several times, depending on how much steam one is using. I also like that the vapor steam is so dry that steamed fabrics feel dry to the touch soon after cleaning. I had one problem when an attachment broke -- I e-mailed the representative, who arranged for a replacement piece to be sent immediately, at no charge. It's cute, too, did I mention how cute it is? And it is very quiet, so while you are cleaning you can listen to music, or talk radio, or self-improvement tapes if you feel like improving yourself. Perhaps I should "get a life." But there you have my experience to date.

I broke down and bought a cheap Bissel about 5 years ago. It doesn't have the upholstery attachments, which I greatly regret. I use the Bissel cleaner, which I purchase at Target, and they also have a Bissel Power Booster, very hard to find (I bought it online). The Power Booster is a powder which you add a small scoopful of to the hot water and cleaner into the machine. Makes a huge difference. I love my Bissel, and it's one of the best investments I've made. Like I said, if you can purchase the upgraded model, do so. I only spent just under $100 on mine, and I think it does a pretty good job. In fact, I loaned it to a friend with 4 dogs and a cat. She used it once and was shocked at how clean her carpets came out. She went out the next week and bought her own. This past weekend, I spilled most of a bowl of salsa on my wool carpet. I scooped up the solid stuff, and steamed it right away. The spot is completely gone, and though I had cleaned the rug about 5 months ago, you can't believe how dirty the water was when I dumped it. One more tip, I only steam my carpets late at night before I go to bed. That way, nobody walks on them and they are dry in the morning. Works especially great in the winter, when you have the heat on. Sure beats what the guys with the truck charge!

I have used several different kinds in the past- but I have just bought my second Hoover Steam Vac. I burned my motor up sucking water out of the basement carpet after a pipe burst. I saved the holding tank and immediately went to WallyWorld and bought another one. IMHO they are the easiest to use and remove more water than the others I have used. I do not have pets in the house, but I have a man and a couple boys who track in enough dirt to choke a horse... And by the way, I have bought an extra Ureka upright bagless, yellow, I think Altima? Those are the ABSOLUTE best vac I have ever seen. I have recommended it to several people who have purchased them and love them as well. I didn't realize how much dirt I was leaving with my windtunnel or Kirby until my son brought me his to try. He gave me his, and bought his GF one and himself another. I would buy one at a yard sale if I could find one. I never want to be without one!! :)

I guess I would not feel right if I did not add this important update, as someone else may need help down the line and who knows, maybe it will be useful for them. After thinking (and writing here) that all is OKAY after installing the Gorton size 6 vapor valve, it all worked for about 12 hours, and then the water trickling out of the pigtail issue reappeared, as it did with size D, size C and onwards. I just did not want to even try size 5 as I pretty much had enough. So out of frustration and desperation, I decided to put back on the same Taco 417-3 Vent: https://www.supplyhouse.com/Taco-417-3-Coin-Vent-11389000-p that I had on my baseboard before switching it out and installing a cheap-made size C purchased at a local Home Depot around 18 months ago. Again the reason why I did that 18 months ago is that suddenly there was no heat up into that baseboard and I did not understand about the flexibility (adjustability) of Taco fully as I do now. So, for the last 4 days (notice my silence here until now), I have had no issues. No leaks, the heat works just fine and there is no hissing or banging. It took a bit of an effort to find the right “opening level” on the Taco – the thing is so sensitive that an extra 3 millimeters turn on the adjuster could allow water to leak or 3 mm not enough, the valve would be too closed to let the steam in. But in the end, I think I finally have a eureka success moment. The bottom line, I have learned so much over the last year about this stuff (much thanks to people like you in this forum) and I just wish I would have given the Taco another chance sooner. But then again I have also learned that my PSI on the cut-in can be set to much lower than I had before (I went from 3 PSI -> 5 PSI down to 0.5 PSI -> 2.25 PSI) and still have everything work perfectly. Also, I increased the pitch on the baseboard by another .25 inch, and that never hurts for the return to work properly. I still can’t imagine why none of the 3 Gorton’s worked. You would think that size 6 would do it, but it leaked the MOST out of the three! That company is considered the golden standard of quality but I guess this was not a match to be had. Once again, thank you all for all the help.