Is this valve on or off?

Ball valve, if the red handle is parallel to the pipe it’s on, it’s open. Perpendicular is closed. Looks like yours is open.

If the photo was uploaded for interpretation then it probably saw the white pipe in the running horizontally and assumed the value was on that pipe. Maybe?

But yeah terrible.

I just told it the pipe was in the same direction as the red handle and got this;

"If the red handle is aligned in the same direction as the pipe, then the valve is open.

Ball valves typically follow this rule:

• Parallel to the pipe → Open
• Perpendicular to the pipe → Closed

Since you mentioned the handle is in the same direction as the pipe, water or gas (depending on the system) should be flowing through. If you want to shut it off, you would need to turn the handle 90 degrees to make it perpendicular."

Never used it before, but interesting.

It’s open (on).
The new tap may be designed for a higher pressure than you have in your hot system, and so may flow slower. If it’s unacceptably slow you will need to change the tap for one designed for lower pressure.