Nooo definitely not electricity. I was thinking more along the lines of a wood fire hot tub set up. I’ve seen people make them into cold plunge tubs. I’ll have to edit the post lol. Should have specified.

There should be a threaded hole on the bottom of the ring for a set screw. But the screw is probably gone.

Replace the hardware. $45 at any big box home improvement depot.

Edit: Now I see the other picture. Blast off and nuke the door from orbit. Holy hell! I'm angry for you. Do what the other commenter said, re-bore the hole. You'll need to buy a jig and a proper sized bit.

Consider:

You want to hack job something involving water, metal and electricity, and then submerge yourself in it.

I was thinking of using an electric hw tank for hydronic heat source backup - remember you are getting supplemental heat in a super cold condition when heat pump is less efficient.

Using a heat pump water heater to heat your home with a hydronic system is like trying to cool your home by opening the refrigerator door. A heat pump water heater pulls heat from the surrounding air to heat the water. Then you try to use that hot water to heat that same surrounding air you just pulled the heat from…

Heat pump water heaters don’t make sense in cold climates as they are pulling heat from air that you then have to heat via other means. Stick to gas/oil for supplemental heat or if electricity isn’t that expensive and it doesn’t get too cold you can just use a resistive heater. But that is typically much more expensive than gas/oil.

I would simply remove the old handle, bore the door and install a standard handle.

You could attempt to screw a scrap piece of wood inside the radius of the cover plate, we could give you something to screw to.

this is the other side, which is attached

the handles on all my doors are attached with wood screws into the doors themselves, rather than the opposite handle - the square bar is the only bit that runs through the entirety of the opening and physically connects the two together. The issue I have is there’s not enough wood left in the door to attach the wood screws to the door.. it’s as though whoever installed this has drilled too big a hole through the door

Is your issue that the hole is so big that the handle almost falls through it?

The point is that the screws don't screw into the door, they screw into the other half of the knob assembly. You can see one of the sockets in the picture you show -- it's the tube sticking out in the hole.

Normally, a complete circle is hole-sawn out of the door. What you have there is amazingly slapdash.

https://www.thisoldhouse.com/home-safety/21016489/how-to-install-a-lockset

I’ve uploaded a picture that should show the issue

This shouldn't be necessary. The handle usually is sandwiched between the door with machine screws. Only the latch plate on the edge of the door is screwed in.

door frame here

Don't fuck around with pressure. Even at modest pressure, if you're talking about the size of a bucket, that makes quite a bang when it lets go. Enough to cause serious injury, permanent hearing loss, etc.

The only suitable glass would be those designed for carbonated drinks. And all of those will have narrow openings precisely because they're designed to hold pressure.

A 10" opening at 10psi will have 2500 lbs. of force on it. Only an engineered product like a pressure cooker can withstand that sort of pressure at reasonable cost. Plumbing parts can also be suitable, but you need to make the joints/seals properly. It's not hard, but it's also easy to screw up if you don't know what you're doing.

I doubt there's enough heat in your basement to pull that much out of it to be useful. If it's conditioned, you're just moving that heat twice, and if you're relying on the ground/walls, the heat flux is pretty low.

Simple resistance heating is likely your best bet here. Gets you off oil and is likely only marginally worse performance than an expensive HP heater.

Understood

I used 6" schedule 40 pvc for my spud gun and it handles 80psi fine. It's rated for 180psi.

I have a rather large basement. While it will get slightly cooler, the above ground sections are insulated so it should never drop below 55F.

IIRC, a heat pump water heater will remove heat from the room where the water heater is located to concentrate it into the water heater. In other words, the room will get cooler. This may or may not be an issue for you.

Getting the pressure isnt the problem. Im mostly wondering what the best containers would be for it.

Would a small pressure sprayer work?

Thanks for this tip. Ill tty to see if I can find anything like that, though ive found finding proper pvc pipes is bothersomely difficult. If i can find any ill go for it, but if not ill still keep the water tip. And yeah ill avoid glass, much appreciated

Not american, we dont have that store. As for cheap even the cheap ones around whwre i live seem to be around 35-40 euro. Beside that do they work for casting epoxy? I couldnt find a clear answer

Either the door is twisted or the frame is not plumb. Easiest solution is to unscrew bottom hinge from the door frame and pull it out slightly and refix with 1 screw and try the fit. The other option on the closing side of the door run a scribe line down the frame and plane off with a rebate plane. Last couple of inches will need to be taken off with a chisel