Unvented hot waterstorage systems exam questions HELP!!

[graham1030]

Hi,

Sorry if this is in the wrong section but i needed help quick so put it in the busiest section.

I took my Unvented hot water storage system exam today but failed on exam 2 as i got 2 questions wrong. It was an open book exam but i couldnt find the info anywhere. I have 1 more chance to re-do it tomorrow but still cant find the answers i am looking for.
I cant remember the exact questions but have a rough idea so if anyone has any idea of the answer please le me know or advise me on where i might find the information.

1. Something like.....
In a new build or where a material change of use occurs a bath should be limited by the use of:


2. where a system incorporates a high temp heat source of 80 c eg solar how would you control the temp


i know this probably makes no sense but i am quite desperate as i have read through tons of pages of info and have not found the answer. Hopefully one of you guys will have done the exam recently and maybe know what im talking about

Thankyou

 

[mark_mc]

2 answer is a thermostatic mixer valve (trv) to give the correct temp for hot supply
and i dont understand the 1st question

 

[graham1030]

thankyou for your help,

all i can remember is the answers to one question. i think it might have been the bath question were something like

a. 6m length pipe to allow cooling of the water
b. some sort of valve set to 80 degrees 1m from the bath
c. some sort of valve set to 60 degrees 1m from the bath
d. some sort of valve set to 48 degrees 1m from the bath

 

[tamz]

It needs a thermostatic blending valve set at 48 deg.

 

[mark_mc]

well its not (A) THAT WOULD JUST BE MAD, ITS NOT (B) AS 80 WOULD BURN A CHILD
ITS EITHER C OR D I WOULD PERSONALLY GO WITH D SAFE TEMPERTURE OF WATER

 

[ecowarm]

G3 Hot water supply and systems

Requirement G3 sets out enhanced and amended provisions on hot water supply and safety. G3 applies safety provisions to all types of hot water systems and new provision on the prevention of scalding.
The former G3 only related to unvented hot water storage whereas the new requirement applies to all types of hot water systems.
The first part of G3 is a new requirement that heated water be supplied to any wash basin or bidet in, or adjacent to, a room containing a sanitary convenience; any wash basins, bidet, fixed bath or shower in a bathroom; and any sink in an area where food is prepared.
The second part of G3 is new and requires that any hot water system, including associated storage or expansion vessel shall resist the effects of any temperature or pressure that may occur in normal use or as a consequence of a reasonably anticipated malfunction.
The third part of G3 requires that any part of a hot water system incorporating a hot water storage vessel shall contain precautions to ensure that the temperature of the stored water does not exceed 100 degrees centigrade and that any discharge from safety devices is conveyed to a point where it is both visible and will not cause a danger to people.
The final part of G3 is a new requirement intended to prevent scalding and requires that the hot water supply to any fixed bath in a newly formed dwelling must be designed and installed with measures to ensure that the temperature of the water that can be delivered to the bath cannot exceed 48 degrees centigrade. This will be done by inline blending devices and thermostatic mixing valves.

 

[graham1030]

Thankyou, that is very helpful and answers one question. the G3 Document i was given did not contain this new info so thankyou.

There was another question on the mock paper i got wrong which still confuses me.

It was something along the lines of.....

The expansion valve discharges hot water at 65 c. what could the cause be:

a. expansion vessel
b. check valve
c. pressure reducing valve
cant remember the other option

 

[tamz]

I think you should have a better read through your course books as this is all simple stuff you should and need to know.
Download yourself a free pdf version of building regs part G. It will benefit you to learn and remember the main points at least.

 

[ecowarm]

you need to study those books more, getting answers on here and your probably not take in this either.

Listen and learn and then take exams, if not sure ASK and ASK again untill you know.

Its not a hard exam you just need to listen and learn, take notes along the way, and its open book! you get plenty of time look through the books and find out the answer.

If we give you all the answers and you dont take it in, it can be very dangerous.

Eco

 

[graham1030]

i have read through the book countless times and have learnt practically all of it. the questions i got wrong were not mentioned in the book and the question i mentioned above i was 99.9% sure was right but they said it was wrong. I got 100% on my 1st exam 2 out of 30 wrong on the 2nd and 100% on the 3rd so i must have learnt something. Thankyoufor your advice though, i appreciate it