My heating has developed a leak from the part pictured below. It looks like a pressure relief valve, but that is on top of the red pressure vessel. Its just dripping but obviously I need to sort it. Any ideas what it is and how to fix it? Much gratitude in expectation:D

Not that I have a clue what I am talking about, but it looks like a T junction to me with one end blocked off. I would probably just try tightening it up with stilsens, then on the other hand I would probably end up with a flooded cellar :P

i thought that too but the fact it has holes in it makes me think it isn't, might be a pressure relief valve or something. if your unsure i'd get a heating engineer to look at it

No not just a T unfortunately. The water is dripping out of the little holes on the fitting in the last pic. Just looked at it again and its dripping quicker so I've lowered the water pressure which has helped but not stopped it

i thought that too but the fact it has holes in it makes me think it isn't, might be a pressure relief valve or something. if your unsure i'd get a heating engineer to look at it

I don't mind fixing it (it looks like it would just unscrew) but I don't know what to order/ask for:O

It looks like a vent for releasing air from the system. Sometimes there is a leather type material inside which expands & seals when wet, but shrinks when dry & lets the air escape then reseals when wet again. It would seam odd to have a vent laying flat, normally they are upright at the highest point in the system.

Pressure Relief Valve.

It looks like a vent for releasing air from the system. Sometimes there is a leather type material inside which expands & seals when wet, but shrinks when dry & lets the air escape then reseals when wet again. It would seam odd to have a vent laying flat, normally they are upright at the highest point in the system.

Theres an air vent nearby on the left higher up with a little screw cap on it. I've replaced one before so I'm ok on this, but thanks for trying

Pressure Relief Valve.

Thats what I thought but why 2? The heating runs of a Stanley range oil fired but the actual heating seems ordinary enough. Recently I have removed 3 radiators and replaced another, leaving 9 rads, but everything was working ok, I thought the pressure in the system had dropped because of a dripping thermostatic on one rad and fixed that, then noticed this.

Yep that looks like a pressure release valve.

Guess I'll try and get one tomorrow then, just easier when your confident of what you want;). Going down the pub now to drown my sorrows - hopefully not my house:eek:

Thanks for all your help

Fitted one myself years ago. Slacken the thin lock ring, tighten the cap a 'bit' (technical term to stop it weeping) and re-tighten lock ring.

Disclaimer - The PRV is a safety item protecting the boiler circuit from over pressure, adjust at your own risk!

Very odd place and angle for a PRV. Could be a bodge as the installer didnt have the right part.

All ours have drainage tubing for when they let by.

Seen similar in B&Q warehouse today in their central heating/plumbing bits.

Hmm, I'm confused here. It looks like an unvented / pressurised water circuit because I'm assuming the red tank on the right is an expansion vessel. But then not sure why you have a pump on the left :confused:

So either you have too much water pressure, 2 bar seems quite high, do you know if this is for the hot water feeding the taps or a closed circuit feeding a hot water tank?

Hmm, I'm confused here. It looks like an unvented / pressurised water circuit because I'm assuming the red tank on the right is an expansion vessel. But then not sure why you have a pump on the left :confused:

So either you have too much water pressure, 2 bar seems quite high, do you know if this is for the hot water feeding the taps or a closed circuit feeding a hot water tank?

The little red thing is indicating the maximum pressure, the black pointer is the actual pressure (about 1.4 at the time of photo). Not sure what you mean about the pump? It just shoves the water round the rads or the hot tank depending on where the electric valves send it, wouldn't work without it;) The pipe the offending item is on is the 28mm feed/supply to the boiler (not sure which). I've just been reading the fitting instructions for the range and it does specify a pressure relief valve in this area so I guess they just played safe and fitted it as well as the one on top of the tank. Will dismantle tonight - hopefully just dirt in the valve but we'll see

Fitted one myself years ago. Slacken the thin lock ring, tighten the cap a 'bit' (technical term to stop it weeping) and re-tighten lock ring.

Disclaimer - The PRV is a safety item protecting the boiler circuit from over pressure, adjust at your own risk!

I tried that but it kept dripping so I'll try to get it off tonight - wish me luck:)

surely if the pressure relief valve is dripping it's because there is too much pressure in the system? (which would suggest a fault elsewhere in the system)

I have to say I know absolutely naff all about central heating though...

Took it to bits - not much to it, just a spring, small brass piston with an o'ring seal on it. Some dirt on it so cleaned it all up put it back in - still leaks:mad: So I'll get a new one anyway. The pressure in the system is no different from what its ever been. I think I just disturbed some dirt when doing the rads.

thanks to all for your help:thumbup:

That pressure relief valve was leaking on my heating , i waited until it was due a service to get it fixed. My plumber/cowboy didn't have one so he removed it, blanked the pipe off and came to replace it about six months later ,saying that if the pressure built up too much it would end up in the overflow tank,

Likely a weak spring.

We get them fail with age on our equipment, or they're fine until tested, then leak like a bugger!

Not quite sure how you would know what pressure its set at? The cap just screws up until it stops!

Likely a weak spring.

We get them fail with age on our equipment, or they're fine until tested, then leak like a bugger!

That's we got told about old aunty **** down at the hospital :P

Not quite sure how you would know what pressure its set at? The cap just screws up until it stops!

The spring will be rated, and is usally stamped.

The spring will be rated, and is usally stamped.

I did look at it but couldn't see anything. Ah well its back in now, and has stopped leaking:thumbup:, but I will keep an eye on it. I'll pick up a new one just in case - can't cost much?

Depends. Guess is between £5 and £20 easy.