leaking overflow

[Pipkd]

Hi hoping a) this is right section and b) someone can help me

I live on groundfloor of 3 floored flats (1960s). The top floor overflow was leaking and has now been fixed (leaking from toilet overflow). Now I notice my overflow is leaking. I've checked the water level in relation to the flowing out hole in the cistern of the toilet and the water is way below the leaking level (when cistern is full). It looks as though the bath and possibly the shower feed into the same overflow. the bath is not overflowing, which leaves the shower. how can I check this? The shower is a mira advanced atl if that is relevant. Could it be related to when the power is switched on to heat the shower?

Thanks very much.
Pipkd

 

[gas4you]

Bath overflows usually go into the bath waste, not to outside.

External overflows are usually for toilet cisterns or storage tanks.

Do you have a fortic tank in your flat? If so check the ball valve in the header tank on the top of the cylinder.

 

[Pipkd]

Thanks gas4you.
The overflow is not beneath the toilet but is below the bath overflow overwhich the shower hangs. It bends from the toilet area inorder to come out of the flat underneath bath area - i wasn't sure if it was relevant or not so thought I should mention it.
Is a fortic tank only the big blue tanks that are a brand name? If so I don't have one. (I googled it!)
I have a santon immersion heater in the airing cupbaord backing onto bathroom and a large metal (possibly watertank?) above that. When I go up there I hear dripping but wouldn't know whether that is part of normal operation.
(the boiler is in the kitchen on opposite side of flat.)
Does this help? If I could get in it would there be something in the metal tank with a ballcock?
Thanks
Pipkd

 

[gas4you]

Do I assume that by a 'Santon immersion heater' you mean an unvented hw cylinder made by Santon?

If so the dripping could be from the pressure/temp relief safety valve due to excess pressure, excess temperature or just a weak valve.

If you have one of these you need a G3 qualified engineer in to look at it for you.

 

[Pipkd]

I think you can assume so - I wrote what is written on the cylinder and it looks like a hot water cylinder. Would that dripping you mention above result in a leak out of the overflow pipe? Could it still be a problem with the ballcock in the top metal tank? It's quite a snug fit be we've felt around inside and located a ballcock.
Thanks again
Pipkd

 

[gas4you]

Could still be the ballvalve. The Santon though as unvented, is mains pressure and doesn't have a ballvalve in a storage tank

 

[Pipkd]

most intriguing - I think I'm going to have to get someone in - the flat has had work done on it and seems to have two water tanks, one boiler and and one central heating cylinder and more pipes than it could possibly need - some of which are cut off mid section! It makes it difficult to work out what is actually working and what is nolonger in use. I just want to be as informed as possible before I let someone loose.
i don't think I can replace the ballcock (if indeed there is one - my partner checked not me) as you can't see into the tank its so close to the top of the cupboard.
Thanks for you help and any advice on getting someone in gratefully appreciated.
Thanks
Pipkd