Leak in Hot press - HELP

Lex Luthor

Just noticed some water on the ceiling in the kitchen under the hot press. Went to the hot press and found water had just been coming out of the item shown in the picture. I believe its some sort of pressure relief valve.

Any idea why this would be happening apart from the obvious that its over pressured? What can I do to resolve this? Also the adjustment screw at the top of it...what should it be set at?

Heating is off now so its stopped....if I just bleed off some rads will it help?

Picture quality not great but I think its clear enough...

Lex Luthor

Just had a quick look at the over pressure valve and apart from the water coming out the top, it also looks like its coming out of the area just under the cap as shown by the yellow arrows....

This should surely be sealed, so it looks like the valve has just sprung a leak..
Even with the heating off, if you tap the valve, it leaks a little around the area pointed out...

I suppose they are easy enough to change...just open...while the heating is off and replace. I've checked the pressure in the system with the heating running and its just about 1bar which I think is right.

foamcutter

It's an automatic air bleeder. Are you sure it's coming out at the rim. They usually (when faulty ) leak at the cap on the top. You can tighten the cap to stop it leaking. Then you can get it replaced. Make sure to let the pressure off first and drain down part of the heating sytem otherwise you will get soaked or flooded.

pipers

replace

Its called an Bottle vent.

Lex Luthor

ok, first thing in the morning I'm going to try and replace...how do I drain down some of the system and let the pressure off first before replacing?

Lex Luthor

Ok, I was able to get off the pressure relief valve (bottle vent) and temporarily put a straight through fitting with a red handle valve on it its place. AT least this way I have stopped the leak. I wasn't able to source one of the bottle vents today (Sunday - Woodies around the corner don't stock that sort of thing). I suppose it'll be chadwicks or a builder providers tomorrow. Writing on it has 110deg C 10bar. Is that pressure not a bit on the high side for safety?????

pipers

Its not a pressure relief valve.

Its an automatic air vent (bottle vent). Its fitted in the hot press because that the highest point in the pipework. Air is lighter than water, hence why its fitted there. You will get away with not replacing it, but you will occasionally have to vent it.

pipers

B & Q might stock them today.

Lex Luthor

pipers wrote:

B & Q might stock them today.

Thanks Pipers...nowhere near B&Q today...one in Newbridge not open yet...I'll be near Liffey Valley tomorrow so I'll try there if I don't get to a BP first.

I had a look at a few websites and never once seen anything called a bottle vent...plenty pressure relief valves mentioned in there though.

However, I did notice down at the oil bioiler there is a little device with "3 BAR" written on it right at the same point of the pressure gauge. It actually comes on the same manifold as the pressure gauge. Is this the pressure relief valve?

I'm thinking of adding in a gauge also up in the hotpress above the point where I have just installed this hand valve and on the same line as the bottle vent that will be put in. Do you think it might be a good idea to have a gauge there to get a reading? What typical readings should I get here?

I think I'll put in another one anyway, because I know I'll forget to vent the system over time.

JamesM

Pipers is correct - it is an automatic air vent. They often leak ! You can replace it, or not.
The only reason to have a pressure gauge in the hotpress is because you may see it easier than at the boiler. There is probably a safety valve close to the boiler.
1 Bar is about correct when the system is hot. You can cause leaks at rad valves (and automatic air vents) if you have it too high.
Jim.

Lex Luthor

New air vent installed today with pressure gauge.

Few questions...after I installed the air vent & gauge, I opened up the locking hand valve and introduced the gauge and the air valve into the loop. The air vent started to hiss as if it were releasing air although I just imagine it was the air that was in the new manifold I put in

As soon as the air expelled, water then started to come out the top. Are there 2 types of air vents, automatic & manual..? Did I get a manual one, cos I don't remember the previous one letting water out the top.

Also, I got no reading whatsoever on the gauge. Does it look like I will have to manually vent the system anyway with this new valve every month or so? Any suggestions?

Also, I found a quarter turn hand valve in teh hot press on the pipe that supplies hot water to the cylinder. What would this be there for?