How Unvented Hot Water Works

[@chohanchohan8208]

BEST video on unvented faults...

[@nilesh74in]

Perfect video. This is called a video. All fault explained.

[@aball4114]

Good demonstration of the components, and I learned a lot from it. The instructor mistakenly refers, however, to "temperature" at 1:56 and 1:58 when he means pressure. The left gauge is a pressure gauge, not a temperature gauge.

[@Greggspies]

Great module and explanation sir

[@adzyk6197]

Hi there. By no means am I a qualified tradesman, but just love learning about different systems etc.. This video is fantastic, as it shows in a simplistic way how an Unvented hot water system works. The one area that I cant get my head around and understand and if the gentleman who made the video could kindly shed some light on it is: The expansion vessel is connected inline with the cold water supply to the boiler. Which means there is cold water in that part of the system, so why would it expand??? My understanding (limited of course!) is only hot water expands due to raised temperature, as molecules become more spaced out etc. So why would the expansion vessel not be on the other side of the system, meaning on hot side?? On the other hand I can understand why the expansion valve is there because if there is a fault in the pressure limiting valve then it will release that extra pressure. If the expansion valve is there for safety and to regulate the pressure then what is the role of the expansion vessel, why is it needed? Sorry I ask too many questions!! Please can somebody explain and give me the light bulb moment! Thanks in advance.

[@Kalabenos]

There is no valve separating the supply side of the boiler from the hot water side. This means that if the pressure rises it wil rise on the supply side as well, up to the point of the check valve (which is probably built into the pressure reducing valve in this setup. The expansion vessel is there to maintain a more constant pressure in the system within normal operating limits. The pressure relief valves act as a safety measure in case these limits are exceeded.

[@Roger-Bisby1]

excellent video. Nice rig

[@robertmalcolm9358]

Great video

[@suj1945]

Really good explanation :)

[@ismartgas7073]

Well explained

[@malcolmbale9566]

What pressure needs to be in a replacement expansion vessel?

[@nickburlton5821]

Thanks Terry!

[@brandonbrazier7110]

its very good for the plumbing level 2's and 3's

[@Phiyedough]

Very useful video.

[@cen2s2s]

Why does it need both an expansion vessel and an expansion valve with tundish?

[@rohitnarang3123]

Happy new year’s

[@tr-maroc4977]

Hello i thank u so very much for ur explain. Im azzeddine from morocco my job is plumber n i need to learn chaufage central if do not mean we need from you to give us some teachs... Im sorry for my english i will bevhappy hear soon

[@jeffgibons1540]

In theory, could you still get hot water with the expansion valve turned of?

[@Phiyedough]

You would get hot water but you would also waste hot water as the expansion water would go down the drain through the relief valve.

[@herobo123456]

You would never get all those faults occurring at the same time perhaps one individually

[@anthonymassimo3843]

Great video