I took off a radiator for decorator in our house and capped off both pipes. After I'd removed the radiator I noticed the boiler pressure was at "0" but it refilled no problem.
When I've got to REhang the radiator and removed the cap nut on the thermostatic valve loads of water started spraying out so I tightened the nut back up and walked away.
The valve is off so I don't understand where the waters coming from.
Any suggestions or do I need to call a plumber? Looked at draining system but there's no tap on system or any radiator. I know it can be done as I know plumber did it but wasn't watching how he did it.