Econonomy 7 hot water cylinder

albyota

the storage tank in the loft is what provides the pressure to your existing cylinder by gravity, the hot water vents to this tank.....with an unvented cylinder...you get rid of the tank in the loft....then excess pressure is taken up with an expansion vessel, the mains cold water then feeds the new unvented cylinder so your hot water taps are then fed at mains pressure......

pingua

Not sure what to say to that !!!!!!!!!

Perhaps I need to read it a few more times....

pingua

Think I may have opened a can of worms...... and spent too much already!

albyota

STREWTH PINGUA......questions, questions, I come on here for a bit of peace and Qu..........ooooh sorry...;). right....you must have mains pressure cold water coming into your house....right. all you are doing is re-directing that pipe which, at the moment, is in the loft feeding the tank up there...the new cylinder will come complete with the expansion vessel and all its safety devices as a packaged system. you connect hot takeoff pipe to it...cold mains to bottom, and.... here goes :rolleyes: a discharge pipe..... but your plumber will do all that for you.....

pingua

Oh you are an angel and the drinks are on me if we ever meet !!

Yes, I am a woman so I am allowed to be hard work am I not??

Thank you very much for all your help and you have passed the patience of a saint test. 10 out of 10 for you!!

albyota

glad to help....

JennyR68

albyota wrote: »

OH....Yes.....Good scrap!!....but the plumber will probably nick it, by the way you will have to inform the local authority if you install an Unvented cylinder, your plumber will do this on your behalf.

I'm the third type.....can't remember what it was I was counting.......

Why is this? we're in process of changing to direct unvented and no one has mentioned that!

albyota

from building regulations Part G......G3. Hot Water Storage
Tradition hot water storage systems have vent pipes which discharge over top-up cisterns, usually in the roof space, for safety.
This regulation, however, allows for pressurised, non-venting storage systems which can be located anywhere in a dwelling but still deliver water under pressure. Very convenient! However, if the water gets above 100O centigrade it would turn to steam and exert great pressure on the storage vessel and an explosion would occur! Therefore these systems have to be properly designed and contain pressure, temperature and overflow safety devices.


Unvented and vented systems both provide hot water at mains pressure. They achieve this by slightly different methods. There are however certain considerations when choosing the system that suits you best. Unvented Mains Pressure Systems

• In an unvented system you will be storing a large volume of hot water under pressure. For reasons of safety such systems must be installed by qualified technicians with relevant experience, CITB training and G3 certification.
• As a precaution, pressure-relief pipework and valves must be installed to protect against unsafe pressure build-up within the vessel which could result in explosion.
• Your Local Authority (Building Control Dept) will need to be advised of your intention to install an unvented system.
• For reasons of safety, your system will require annual maintenance to ensure safety equipment is functioning correctly (BS2870).
• An unvented system must be commissioned and certified by the installer.

albyota

some good info here....http://www.hotwater.org.uk/q-and-a.php

JennyR68

Do I presume my plumber knows all that and will handle it or do I have to do something?