[PIC] What's this thing in my hotpress?

fullerand

Hi there,

I have a closed central heating system at home, and in my hotpress I have a water top-up valve, a pressure gauge, and what seems to be a brass pressure release valve on the loop that goes out to my radiators - see pic attached.

I took 2 radiators out of the system at the weekend (we were painting the room), and later when I turned on the heating, water sprayed out of this thing, and the pressure dropped to zero. I was able to get things working again by topping up the pressure, but I'd like to know if that's normal behaviour - especially before I add the two rads back in this evening

Any advice welcome, cheers.

jigsey

pressure release valve

corkgsxr

Auto air vent. But if it sprays water it's shagged.

Also if your pressure went down that fast your expansion vessel needs topping up / replacement

fullerand

Thanks guys. Auto air vent it is, so!

Just to clarify, it wasn't continually spraying water - all I know is that after turning on the heating and the rads hadn't heated up 10 minutes later, I checked the hotpress and found a small puddle of water on the ground under this thing. Maybe it just pulled a bit of water out when it was venting the air?

Re expansion vessel - forgive my ignorance but is the idea that it's full of extra water that should automatically top up the radiator loop when the pressure drops? Not entirely sure that I have one...