Unvented Cylinder - leaking pipes when system off only

Sharons1987

Hi all

bit of an odd one - does anyone have any thoughts as to why 2 of the pipes coming off my cylinder (leading up to the heat exchanger) leak whenever the system has been off a while (ie if I don’t put heating or water on for say 24 hours) - it’s not condensation as too much water. Image attached (this is the pipe work just Above the bypass valve)

 It only happens if the system is off / cooled down - really keen to solve as it sits right above my fuse box so worried about electrics and water! 

Thanks! 

Grenage

The water is probably evaporating when the system is on (and the pipes are hot).

Jeepers_Creepers

As Grenage says. That small leak could easily be evaporated when the pipe is hot before you notice it. Or, the leak could be tweaked off by the pipe and fitting expanding when hot.

Either way, the fix is soooo easy it's like falling off a chair, getting up, going out to your garage, fetching an adjustable spanner, and tightening that nut by around a quarter of a flat's worth.

Sharons1987

Thanks @Jeepers_Creepers and @Grenage however ... the engineer who’s already been here a few times to fix other bits like replace the blown PRV did just that - tightened everything 3 days ago! Is there anything else it could be or that would help? Just worried with elec below! Does the whole thing need replacing?  I’m more concerned when come summertime I don’t want the heat on that it’ll be everywhere 😬 

Jeepers_Creepers

Place a towel or similar over the socket

If such a joint leaks it's either because it hasn't been done up quite tightly enough, or because the - what I'm guessing is a fibre - washer is damaged. (Or the brass seat the washer goes on is ditto.)

BUT, this is easy peasy for a plumber. Power off, depressurise system, shut off red valve, undo nut fully to investigate (whilst catching any water that comes out) and sorting the issue - new O ring or a smear of Fernox Hawk. Redo.

But, if you have an adjustable spanner, there is no harm in trying another small tweak - we are talking a 5-10mm circumference turn.

Sharons1987

Jeepers_Creepers said: oh

Place a towel or similar over the socket

If such a joint leaks it's either because it hasn't been done up quite tightly enough, or because the - what I'm guessing is a fibre - washer is damaged. (Or the brass seat the washer goes on is ditto.)

BUT, this is easy peasy for a plumber. Power off, depressurise system, shut off red valve, undo nut fully to investigate (whilst catching any water that comes out) and sorting the issue - new O ring or a smear of Fernox Hawk. Redo.

But, if you have an adjustable spanner, there is no harm in trying another small tweak - we are talking a 5-10mm circumference turn.

That’s such a relief thank you so much!!

Jeepers_Creepers

You ain't dun it yet :-)

Keep us posted.

Sharons1987

Jeepers_Creepers said:

You ain't dun it yet :-)

Keep us posted.

Haha will do!

Jeepers_Creepers

Grab the red valve firmly in one hand as the nut is turned - just a few mm. See if that sorts it or makes a difference.

If the red valve is threatening to turn at the same time - unlikely, but possible - then that'll need holding firm with another wrench to prevent this.

Sharons1987

Jeepers_Creepers said:

Grab the red valve firmly in one hand as the nut is turned - just a few mm. See if that sorts it or makes a difference.

If the red valve is threatening to turn at the same time - unlikely, but possible - then that'll need holding firm with another wrench to prevent this.

thank you! gonna have a plumber come do it because theres also a drip from behind this black element just above - any ideas what that is called / what might cause that? its def not from any further above - have checked in real time, its somewhere right behind. (original leak spots in green, the other i'm referring to above in the blue)

Currently its basically at a stage where either the water or heating needs to be on every 4 hours or so to avoid getting to that leak point - not ideal!

Jeepers_Creepers

Thank you for showing me pics of things I've never seen before in my life :-) Ditto the brass fitting with the cable to its left.

The two fittings circled in green look like connectors, tho' what you'd connect to things so small I dunno. They have what looks like screw-on 'dust caps' on them to prevent dirt getting in there and to stop any potential drips... By why they're on the flow and return pipes, I've no idea.

That's some system you got there  

I hope that helps... :-(

:-)