Unvented Cylinder - leaking pipes when system off only

Sharons1987

Jeepers_Creepers said:

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... :-(

:-)

thanks anyway yes its a bit wild....its a water cylinder connected to district heating system for the block but NO IDEA whats what on any of it! thanks anyway will await the plumber

Jeepers_Creepers

Interesting stuff - but beyond anything I'm familiar with I'm afraid.

What is the ultimate source of heat?

Sharons1987

Jeepers_Creepers said:

Interesting stuff - but beyond anything I'm familiar with I'm afraid.

What is the ultimate source of heat?

Communal boiler externally services all the flats pipes come in to unvented water cylinder that services both hot water and heating!  Tbh I hate it and it’s a money pit already - very complicated system (here anyway) 

Sharons1987

@Jeepers_Creepers could i pick your brain on one more Q - would it be unusual for the pipes into cylinder to still be pretty warm (not quite hot but warm) long after everything off? hot water on for 30 mins this AM 7am-730am, system off at wall since (was testing if leaked still when totally off) - pipes still warm inc where the cold inlet meets the cylinder..... flow and return not warm though 


thoughts? 

Jeepers_Creepers

Assuming the water in the cylinder is now hot, it shouldn't come as a surprise that the pipes going into it are kept warm.

I'm assuming you mean the pipes that are used to heat it up - the flow and return from the 'boiler'? When the 'hot water' was on for these 30 mins this morn, these pipes you are referring to would have been pretty hot? Inside the cylinder the pipes form a coil which sits in the cylinder's hot water - heat is transferred via this coil. Once the heating flow has stopped, the no-longer-heated coil is now sitting in hot water, so I would expect that heat to effectively transfer back out the pipes to some degree.

Why do you ask? Heat loss? Are the pipes lagged (as they should be)? If so, I'd guess that heat loss through there would be minimal.

Sharons1987

Jeepers_Creepers said:

Assuming the water in the cylinder is now hot, it shouldn't come as a surprise that the pipes going into it are kept warm.

I'm assuming you mean the pipes that are used to heat it up - the flow and return from the 'boiler'? When the 'hot water' was on for these 30 mins this morn, these pipes you are referring to would have been pretty hot? Inside the cylinder the pipes form a coil which sits in the cylinder's hot water - heat is transferred via this coil. Once the heating flow has stopped, the no-longer-heated coil is now sitting in hot water, so I would expect that heat to effectively transfer back out the pipes to some degree.

Why do you ask? Heat loss? Are the pipes lagged (as they should be)? If so, I'd guess that heat loss through there would be minimal.

perfect exactly as i hoped! i only ask as i had a worry for a while that the stat was playing up on the cylinder and continuing to heat when off but no signs of this - the pipes up to the heat plate yep are usually boiling hot while its on and are cold now.

the ones that are still warm are directly off the cylinder and lead around and into where the motorised valves are and directly off the cylinder so makes sense they would be a letter warm per your coil comment

thanks so much, feeling less stupid by the day!

Jeepers_Creepers

Sharons1987 said:

perfect exactly as i hoped! i only ask as i had a worry for a while that the stat was playing up on the cylinder and continuing to heat when off but no signs of this - the pipes up to the heat plate yep are usually boiling hot while its on and are cold now.

the ones that are still warm are directly off the cylinder and lead around and into where the motorised valves are and directly off the cylinder so makes sense they would be a letter warm per your coil comment

thanks so much, feeling less stupid by the day!

And yoor making me feel more cleverer. :-)