Mira Advance 8.7KW, very poor water flow rate

[Blissof89]

Just been to see a friend who has a Mira advance 8.7 in his flat. Flow rate of the water is terrible, he was saying he had looked online and seen they do 11KW showers and was asking if he could change if for a bigger one.

Does anyone have any experience with the Mira Advance? Is the water flow always ---- poor? It seems really bad for an 8.7KW shower, I usually fit Triton 7.5KW's at work cause we only have 32A supply to work with and they seem better than this.

11KW shower seems a bit overkill to me but i could do it, 10mm T&E feeding the current shower, rm B and only <10M from DB to shower.

I'm starting to wonder if pressure is just very bad don't want him to spunk £300 on a new shower and have same problem.

 

[Leesparkykent]

Just been to see a friend who has a Mira advance 8.7 in his flat. Flow rate of the water is terrible, he was saying he had looked online and seen they do 11KW showers and was asking if he could change if for a bigger one.

Does anyone have any experience with the Mira Advance? Is the water flow always **** poor? It seems really bad for an 8.7KW shower, I usually fit Triton 7.5KW's at work cause we only have 32A supply to work with and they seem better than this.

11KW shower seems a bit overkill to me but i could do it, 10mm T&E feeding the current shower, rm B and only <10M from DB to shower.

I'm starting to wonder if pressure is just very bad don't want him to spunk £300 on a new shower and have same problem.

What flow rate and pressure are you dealing with?

 

[buzzlightyear]

Try a new pressure switch .

 

[Daniel Oake]

In my experience it sounds like his pressure, if it's gravity fed system I think you achieve something like half a bar of pressure for every meter dropped. increasing his shower KW isn't going to make a difference unless your saying its not heating up enough

 

[buzzlightyear]

Look on fluetube it will show you what to look for regarding showers.

 

[Blissof89]

I'm not sure on what his incoming pressure is like, I'll text him and see what its like on his other taps stuff.

Its an old ex council flat so I guess some of the infrastructure isn't great, think he on zone heating and hot water still hence the need for an electric shower.

I think he knows another lad who is a plumber so maybe he can enlighten us on what the pressure is like coming into the flat.

 

[buzzlightyear]

You can always know if you have good pressure if the kettle goes on quick.

 

[Andy78]

Could be water pressure, could be an internal part of the shower, could be as simple as descaling the shower head.

 

[GBDamo]

In my experience it sounds like his pressure, if it's gravity fed system I think you achieve something like half a bar of pressure for every meter dropped. increasing his shower KW isn't going to make a difference unless your saying its not heating up enough

0.1 bar/m roughly, so if hes gravity fed from a loft tank his pressure could be really poor.

 

[buzzlightyear]

Shower doctor you tune.

 

[ChrisElectrical88]

Purge it. Bottom left of the shower behind the cover is a whiteish button on a metal square part. Try that first to get water flowing and clear any ---- in the pipes. There amazing showers.

 

[David Prosser]

In my experience it sounds like his pressure, if it's gravity fed system I think you achieve something like half a bar of pressure for every meter dropped. increasing his shower KW isn't going to make a difference unless your saying its not heating up enough

10m of head gives about 1 bar, 0.981 to be precise if the water is @4C.
So a 1 meter drop provides about 0.1 bar. Is the cold water tank above in the loft ?

If the OPs friend has mains water supply from Anglian Water then the pressure at his stop tap should be at a minimum of 1 bar.

 

[buzzlightyear]

Ring up mira get their shower engineers to sort it out .

 

[ruston]

Agree with lime scale and/or blockage as a first port of call if it has been working acceptably previously. As @ChrisElectrical88 said they are good showers .

 

[ChrisElectrical88]

Purging it will clear the head mate and put some proper pressure through all the pipes.

Edit, if the pressue comes put crap when ypur purging it nothing you will ever do will increase the pressure and Mira will charge you a call out fee to tell you the pressure is not suitable.

 

[Blissof89]

Would I be able to test the pressure at the shower 15mm brass compression fitting with something like this? Not sure if the thread will fit.

https://tinyurl.com/y5j84x9k

Purge it. Bottom left of the shower behind the cover is a whiteish button on a metal square part. Try that first to get water flowing and clear any **** in the pipes. There amazing showers.

Thanks! I'll try this, I gotta go round and do some other bits for him soon.

 

[shaun1]

Have you tried setting the shower to cold to see what the pressure is like then? That should be the maximum you will get through it.

 

[PEG]

Hi,pressure means nothing,it is flow rate at shower head,which is important. You could have 6000 psi and only get a squirt,every few seconds....(just like a grease gun)

Any minimum stated supply,from the utilities,has always been in terms of LPM,at first drawing....and it is not usually dazzling.

Also,a great many suppliers have a policy of energy/leak reduction,through the small hours,which involves a supply pressure drop of maybe a bar.

Comedy pairing,of flow issues... but only when all known plumbers are asleep.

 

[David Prosser]

Hi,pressure means nothing,it is flow rate at shower head,which is important. You could have 6000 psi and only get a squirt,every few seconds....(just like a grease gun)

Any minimum stated supply,from the utilities,has always been in terms of LPM,at first drawing....and it is not usually dazzling.

Also,a great many suppliers have a policy of energy/leak reduction,through the small hours,which involves a supply pressure drop of maybe a bar.

Comedy pairing,of flow issues... but only when all known plumbers are asleep.

You are wrong with the minimum supply.

It is always on pressure not litres per minute (the flow per minute is only a guide for people with a jug and stop watch).
There are standards set out buy the government (OFWAT) and they are clear. Water supply companies will then set their own standards which at least have to meet the minimum. These are all in set out in pressure (or head) to the stop tap.

If the minimum requirement from OFWAT was 0.7 bar then it would be impossible (without sucking water from peoples house) that it could be as you suggest "suppliers have a policy of energy/leak reduction,through the small hours,which involves a supply pressure drop of maybe a bar".

 

[PEG]

You are wrong with the minimum supply.

It is always on pressure not litres per minute (the flow per minute is only a guide for people with a jug and stop watch).
There are standards set out buy the government (OFWAT) and they are clear. Water supply companies will then set their own standards which at least have to meet the minimum. These are all in set out in pressure (or head) to the stop tap.

If the minimum requirement from OFWAT was 0.7 bar then it would be impossible (without sucking water from peoples house) that it could be as you suggest "suppliers have a policy of energy/leak reduction,through the small hours,which involves a supply pressure drop of maybe a bar".

Hi,no my friend,in the instance i cite,it is yourself,who is incorrect.

Your first error,was reading my post as stating 0.7 as a minimum supply pressure. I do not.
You will see i state "pressure drop of...",which is correct,and they do,and i have the email statement from United Utilities,who supply our locality,if you need it.

The suppliers who adopt this method,and yours may not,are very cagey about sharing this information. It indeed,took a lot of back and forth,including their fitting of data monitoring device,for a week.

This showed the deviation in supply pressure,a reduction being measured in the time period mentioned - on the minute.

The minimum supply pressure,as stated by WRAS and the other groups,is 9LPM at 10M head.

If you require any other information or data to corroborate my post,please feel free to ask. It is considerably more friendly,than "you are wrong"

 

[PEG]

The water supply companies are very cagey,as i mentioned,but Southern Water,has a mild statement of intent,on their web page,under the title of "Managing water pressure".
They tell you what they do to the pressure - and when they do it

 

[David Prosser]

I apologise it does come across unfriendly when I read it back through. However I never suggested that you stated a 0.7 bar or any other figure.

Although it may appear to be 9LPM at 1bar, if you look through each provider has a different legal minimum pressure with the lowest being 0.7bar. There are several permutations on this revolving around the number of homes supplied of each point etc etc but this is the basic figure you should expect at your stop tap.

The management of water pressure to reduce leaks is common to all water supply companies however it is used to bring pressure back down over night balancing out for lower demand this should not of effected you and I hope you got your compensation.

 

[PEG]

Cheers for the reply,my friend. I have to admit to a bit of insider information,on this,as not only have i dealt internally,with United Utilities,we have lots of friends,who are employed by them,stretching throughout the organisation.

This means,we have been privy to policies and information,some of which is not meant for "external consumption"...should we say

In my own personal quest,for information,i was blanked completely,and went through the list of hurdles,to the final one,where they fitted the data capture device. This was superfluous,as i had done this already,and only confirmed, my original complaint.

I knew the company policy,regarding this method of reducing leaks and energy costs....and to be fair,the lad who fitted the device,confirmed it...albeit,off the record...

The first 3 people i dealt with,denied the deliberate reduction in supply pressure,between the hours i described. The final email i received,confirmed it,and the reasons for doing it,and included my data capture read-out,which mirrored my own.

I never wanted compensation,and was never entitled,as the supply directives are still met. The minimum supply statements,all vary,and some,including my own provider,state "minimum supply head of 10M or a filling a 4,5 litre bucket from first drawing,in 30 seconds..."

The bucket nonsense,alludes to the 9 lpm,but the most important word in that statement...the one they go back to,when issues arise,and i have been involved in such matters....is the word "or".

They can stretch out this dual value,to the point where you are sick of making cups of tea,for the half dozen supply assessment and sampling technicians...which you have missed a days work,to meet....in the end...bottled water starts to look cheap

We are lucky enough to have,in Urmston,the world's first municipal sewerage treatment plant,at Rivers Lane,and it is still in use.
My pals farm is next door (the farm is mapped 300+years ago) and the site and it's history is absolutely fascinating - space-age gas capture and generation,right alongside parts which have working infrastructure,older than anyone's nan

Anywho,i have probably bored you to the extent where you feel like running some water and pushing my head in it

 

[ChrisElectrical88]

Soooo anyone know of the showers working yet?

 

[DPG]

Am I on the bloody plumber's forum or something?

 

[Blissof89]

Finished a bit early today so I'm actually just sitting in the van waiting for him to get home so we can give this purge thing a try.

Fingers crossed

 

[Blissof89]

Arrived and the shower was on the bathroom floor Apparently his mate had a couple quiet days so he is retiling bathroom and kitchen and removed the shower so he could take tiles behind it off .

I found the purge button but it doesn't seem to work with no water or electric connected . His pressure seems fine to me although I had no way of actually testing it, runs out the taps pretty rapid though.

 

[David Prosser]

Am I on the bloody plumber's forum or something?

I suspect most plumbers can only just manage the bucket never mind a pressure gauge and stop watch !