Help with unvented cylinders central heating

[Old Account]

Thnx Ron, shows you have a lot of learning ahead of you 🙂

Thanks shauni, but let me tell you everyone of us, will learn the whole life.

But do t take it wrong as you always do. 😉

 

[tolly]

Nothing wrong with a lever valve on hot outlet at all. Some people will do this where they have a balanced cold coming off a the combination valve so your not turning the hot and cold off together all the time when using the lever valve before the combination valve.

 

[Chalked]

When installing unvented I fit a lever valve on the inlet to combi valve. This enables easy servicing. I then fit one to the balanced cold AND the hot outlet. This enables you to isolate just the hot, or cold for maintenance.

The big mistake I see very regularly, is a valve on the cold feed to the cylinder! Between the combi valve and cyl. This wil cut out the expansion vessel and expansion relief in one go.

 

[1Steven]

Just come across prv after the tundish!

 

[ShaunCorbs]

Do many people fit hotun?

 

[Chalked]

Iv fitted a few hot tuns. They do get around difficult vent runs

 

[ShaunCorbs]

Iv fitted a few hot tuns. They do get around difficult vent runs

Problem is now they can't take the flow, they spill out when blowing off

Twitter

 

[Harvest Fields]

That's bad 😱. Has anyone had a response from hotun? If so what did they say?

 

[Chalked]

You can get a cover

 

[ShaunCorbs]

You can get a cover

Still spills out of it

 

[ShaunCorbs]

That's bad 😱. Has anyone had a response from hotun? If so what did they say?

Yep only tested to 18lpm

 

[Chalked]

Tbh. Something massively wrong if one of the relief valves are passing that amount. I bet the standard ones can't take that either.

 

[ShaunCorbs]

Tbh. Something massively wrong if one of the relief valves are passing that amount. I bet the standard ones can't take that either.

Just fully open and stnd tun should be fine

 

[Adam Perry]

Done my unvented in the end so all qualed now however, before my course i rang gas safe who can advise on building reg G3 who said that as long as your not installing an unvented cylinder, then it is completly fine to work on it and change components!!! This is how companies get around it......although the instrucror on the course said they are talking Rubbish!!! Very grey! Non the less i have the qual now

 

[ShaunCorbs]

Your tutor is correct

If gas safes logic transfers that means you can repair gas appliance eg boilers without needing to be qualified

 

[Ric2013]

So all hot water installations are notifiable...

unless testing and adjustment is not possible, or would not affect the energy efficiency of the fixed building service

Surely, then, that would apply to a normal, old fashioned, DHW cylinder? What can I adjust and test except the thermostat? The main energy efficiency (seeing as the cylinder always comes pre-insulated) would be in the proper horizontal run before the vent and the pipe lagging; the safety lies in the design of pipework. Both of which would be 'tested' by visual inspection, certainly not 'adjusted' in any way.
If I'm wrong, of course, then this makes a mockery of the C&G level 2 assessment in which you must design, install, and remove a hot water cylinder and header tank?