Water pump adjustable pressure?

metricspaces

I have a Stuart Turner Monsoon S2.0 Twin water pump in my house. I'm wondering if the pressure on these are adjustable?

The reason I'm asking is that the pressure seems very low.

The house is a standard new build semi-d. The water pump is brand new.

The house is not in an area with poor water pressure.

In comparsion to a Triton T90 shower the pressure is nowhere near as strong from my water pump. Should it be?

Sleeper12

metricspaces wrote:

In comparsion to a Triton T90 shower the pressure is nowhere near as strong from my water pump. Should it be?

An electric shower like a t90 pumps out 4 litres per minute or less of hot water. Your 2 bar pump should be pumping 14 litres plus per minute.

Something is definitely wrong. This might sound like a silly question but are you sure that the pump is switched on? Does it sound like it's pumping water or just humming?

metricspaces

Thanks for the reply. Yes the pump is definitely on and is making a noise.

Is the pressure on the pump adjustable? I'm wondering if it has just been set to lower than 2bar and needs turning up.

I've yet to move into the house so I had the pump switched off. So it's been mostly off since installed by builder a few months ago.

When I turned the pump on today I still had very low pressure, but pressure increased after a few minutes.

Turning on the tap in the bathroom has a noticeable effect on reducing the pressure in the shower. This system seems nowhere near operating at 2 bar.

metricspaces

In my kitchen where the cold water is coming from the mains (i.e. not going through the pump), the pressure from the cold water is greater than the pressure from the hot water (which obviously is going through the pump).

There is no other use of water in the house when I'm doing this little test.

I'm guessing the mains is not coming into the house at anywhere near 2bar? (a quick Google seems to suggest mains is 0.5bar or less in Ireland)

Sleeper12

What type of shower head have you got? The bigger the head the weaker the pressure, or at least the impression of less water.
Stuart Turner monsoon comes with a 5 year warranty so you know that you will be looked after if it is the pump.

metricspaces

Shower head is just your standard shower head. Not much different to the ones that come with a Triton T90 shower.

Do you know if the pressure of the pump is adjustable?

metricspaces

Shower head

Here's a video where you can see the pressure. When I turn the tap on you can see the pressure in the shower drop dramatically https://streamable.com/vuaw6

sky6

It could possibly have been piped wrong. Can you post pictures of the Plumbing around the Pump and Cylinder.

exaisle

If you're in an area with hard water, the head of the shower may be partially blocked...dismantle it and soak it in vinegar to clear it (or attack it with a pin to unblock the holes)....

metricspaces

exaisle wrote: »

If you're in an area with hard water, the head of the shower may be partially blocked...dismantle it and soak it in vinegar to clear it (or attack it with a pin to unblock the holes)....

Everything is brand new. New house. New pump. New shower. So I think that should all be ok.

K.Flyer

To answer your main question, No, the output of the pump is not adjustable, it is fixed.
Have you checked all valves on the pipes to and from the pump to ensure that they are all in the fully open position (lever valves are marked, round handles open anti clockwise)?
Is the issue on both the hot and cold selection of the shower valve?
Does the pump service anything else, e.g. taps in the same bathroom, is the pressure low on these as well?
If everything is a brand new installation, why have you not contacted the installer?

metricspaces

K.Flyer wrote: »

To answer your main question, No, the output of the pump is not adjustable, it is fixed.
Have you checked all valves on the pipes to and from the pump to ensure that they are all in the fully open position (lever valves are marked, round handles open anti clockwise)?
Is the issue on both the hot and cold selection of the shower valve?
Does the pump service anything else, e.g. taps in the same bathroom, is the pressure low on these as well?
If everything is a brand new installation, why have you not contacted the installer?

Thanks. I will check these things.

The pressure with hot and cold is the same.

As far as I'm aware the pump services every water outlet in the house (bar the mains in the kitchen). It even comes on when you flush the toilet.

I've never had a shower in a house with a water pump before. So I don't know what I should be expecting from a 2 bar pump. I've nothing to compare it to. Yes I'll ask the builder, but would like to be somewhat informed beforehand.

Even though I've never had a water pump in a house before. I've read that mains supply in Ireland is less than 0.5 bar, am I right in thinking that the hot water coming out in my kitchen (going through pump) should have higher pressure than my cold water in the kitchen (coming from mains)?

Sleeper12

I'm just looking at the video now and I think the pressure looks OK. I'm assuming when it drops off it's you turning on the bathroom tap?

It's quite a big shower head and looks like a lot of water is going through it. An electric shower head has a lot less holes & the holes are a lot smaller. This gives the impression of more pressure & more water.

Can you measure how many litres per minute you are getting or how many times you can fill a litre jug in a minute? I'm betting you are getting over 15 litres per minute.

Mains water pressure is supposed to be I think 1.5 bar minimum for a household but it can be anything from 1 to 3 bar. Higher in a few areas.

metricspaces

Sleeper12 wrote: »

Can you measure how many litres per minute you are getting or how many times you can fill a litre jug in a minute? I'm betting you are getting over 15 litres per minute.

Thanks! Good idea. So I'll just take off the shower head and see how long it takes to fill a litre bottle. I'll do this a few times after the pump is running for a minute or so, average out the figures, and calculate what it is outputting per minute on average.

How do I find out how many litres per minute my pump should be outputting?

Here's a pic of the pump. It says 9 L/min @ 1.5bar. So it would be 12 L/min @ 2bar?



I checked all valves and they are all full open.

metricspaces

There is also this guage in this hot press. I'm not sure if it's of any relevance here. Is it displaying the pressure of the water (the black hand)?

What's the purpose of the red hand - does the system stop suppling water if the black hand goes below the red?

K.Flyer

Just a quick reply, that gauge is part of the central heating system.
Your pump is rated 1.5 bar at 9 litre /m when operating.
The 2 bar figure is how much pressure could build up behind a closed valve.
I would check the internal diameter of the shower house, some can be very narrow which drastically affects pump performance.

metricspaces

K.Flyer wrote: »

Just a quick reply, that gauge is part of the central heating system.
Your pump is rated 1.5 bar at 9 litre /m when operating.
The 2 bar figure is how much pressure could build up behind a closed valve.
I would check the internal diameter of the shower house, some can be very narrow which drastically affects pump performance.

Thanks. I'll check this diameter and the water flow.

Kinda false advertising for these pumps, to call it a 2 bar pump if it's only putting out 1.5 bar pressure water.

If everything is ok and I want more pressure then what bar would you recommend? I see these Stuart Turner Monsoon pumps come in 2, 3, 4 or 4.5 bar. Presume I can use any of them?

I would like the shower to be quite high pressure. The house has two bathrooms, so if changing the pump I might as well accommodate for the possibility of both bathrooms using water at same time (both using showers, or one shower & other using taps).

Will there be much of a difference in running cost and noise if i go 3 or 4 bar pump?

metricspaces

K.Flyer wrote: »

Just a quick reply, that gauge is part of the central heating system.
Your pump is rated 1.5 bar at 9 litre /m when operating.
The 2 bar figure is how much pressure could build up behind a closed valve.
I would check the internal diameter of the shower house, some can be very narrow which drastically affects pump performance.

I just tested the amount of water coming out and it is about 8.6 litres per minute. As the pump is rated 9 litres per minute this sounds ok?

Internal diameter of the shower house is 7mm.

Does this all sound ok? And if I want more pressure I just need to get a 3 or 4 bar pump?

K.Flyer

metricspaces wrote: »

I just tested the amount of water coming out and it is about 8.6 litres per minute. As the pump is rated 9 litres per minute this sounds ok?

Internal diameter of the shower house is 7mm.

Does this all sound ok? And if I want more pressure I just need to get a 3 or 4 bar pump?

You can get bigger bore than that..
Go into woodies, they have a larger diameter 1.5m length hose for around 16 euro.
Its a cheap try that might help before going looking for a larger pump.

metricspaces

K.Flyer wrote: »

You can get bigger bore than that..
Go into woodies, they have a larger diameter 1.5m length hose for around 16 euro.
Its a cheap try that might help before going looking for a larger pump.

Thanks. I will give this a try.

If I decide to go for a bigger pump what bar should I go for?

K.Flyer

metricspaces wrote: »

Thanks. I will give this a try.

If I decide to go for a bigger pump what bar should I go for?

Before spending on a new pump, I would first ensure all pipework is correct and shower valve filter / strainers are clean.
3 bar would be considered plenty for a domestic installation.
Stick with the Stuart Turner brand.

metricspaces

K.Flyer wrote: »

Before spending on a new pump, I would first ensure all pipework is correct and shower valve filter / strainers are clean.

Does the fact that I am getting almost 9 litres per minute (without the shower head on) not imply that the pipework etc. is all ok?

K.Flyer

metricspaces wrote: »

Does the fact that I am getting almost 9 litres per minute (without the shower head on) not imply that the pipework etc. is all ok?

Yes, sorry I forgot you had checked that, so it probably is fine.

metricspaces

According to this page here https://victoriaplum.com/blog/posts/understanding-water-pressure anything below 10 litres per minute is considered low pressure. Is 9 L/min really the expected flow rate of this 2.0 bar pump?

Based on the information on that site it doesn't make sense that 9 L/min would be the expected flow rate of my 2.0 bar pump. Why would any company make a pump where the flow rate is considered low pressure?

Sleeper12

metricspaces wrote: »

According to this page here https://victoriaplum.com/blog/posts/understanding-water-pressure anything below 10 litres per minute is considered low pressure. Is 9 L/min really the expected flow rate of this 2.0 bar pump?

Based on the information on that site it doesn't make sense that 9 L/min would be the expected flow rate of my 2.0 bar pump. Why would any company make a pump where the flow rate is considered low pressure?

For your shower to be "officially" a power shower it has to be 10 litres per minute. Anything under 10lpm isn't called a power shower.

There's nothing wrong with 9 lpm. In many states in America shower heads have to be limited to 9 lmp max under state law.

The link you posted is by a bathroom company. They have an interest in making you think your water pressure isn't good enough. They would try sell you a new shower with a bigger shower head requiring even more pressure & sell you a 3 bar pump.

It's really what you want out of your system. If you go to a 3 Bar pump (I have one myself) you are going to go through more hot water per shower. I can drain a full tank of hot water in little over 10 minutes. So bigger pump = more powerfull shower= higher electricity costs.

metricspaces

Sleeper12 wrote: »

For your shower to be "officially" a power shower it has to be 10 litres per minute. Anything under 10lpm isn't called a power shower.

Thanks, it really is a power shower I want and I don't mind the extra water\electricity usage.

I got an 11mm diameter shower hose, it didn't make a noticeable difference. I've ordered this shower head from showerpowerbooster and will test it.

If the combination of the 11mm diameter hose and new shower head don't increase the pressure of water coming out enough, then I guess I am looking at getting a new pump.

Before I get a new pump, I really want to be sure my existing pump is operating as expected. I'm a bit confused as to what my pump should be putting out. See the spec here http://www.stuart-turner.co.uk/products/monsoon/s20-bar-twin/

@Sleeper12 you mentioned previously that a 2.0 bar pump should be putting out 14 l/min? But K.Flyer said my pump (based on the photo I shared of the label on it - see below) should only be putting out 9 l/min. That's obviously a big difference of 50%.



The spec of my 2.0 bar pump says "Performance @ 9 l/min 1.5 bar". How do I tell this is the performance to expect when no shower head is on the hose? It doesn't say anywhere on the spec that 1.5 bar is the operating pressure of the pump.

Sleeper12

metricspaces wrote:

@Sleeper12 you mentioned previously that a 2.0 bar pump should be putting out 14 l/min? But K.Flyer said my pump (based on the photo I shared of the label on it - see below) should only be putting out 9 l/min. That's obviously a big difference of 50%.

I was wrong. I was surprised myself when K.Flyer said 9 litres per minute but I don't for a second doubt his knowledge. I deal with self contained power showers and electric shower. I rarely deal with stand alone pumps

metricspaces

Sleeper12 wrote: »

I was wrong. I was surprised myself when K.Flyer said 9 litres per minute but I don't for a second doubt his knowledge. I deal with self contained power showers and electric shower. I rarely deal with stand alone pumps

Thanks! I was hoping you weren't wrong

Just out of interest, how do I tell from the label on my pump (or the specs of the pump online) that 1.5bar @ 9 l\min is what I should expect with the shower head off the hose? Is it the "Duty Head" term that signifies this?

I'm thinking to go 4.0 bar based on my current pump is 2.0 bar and:

1. Visible pressure of the current shower, see here https://streamable.com/vuaw6, it looks like I'd want to double the pressure?
2. Only £60 in difference between cost of 3.0 bar and 4.0 bar stuart turner monsoon pump here https://www.tradingdepot.co.uk
3. If I go for 3.0 bar and pressure is not enough, then I'll have to pay for a 4.0 bar and pay a plumber twice. So for the sake of £60 extra, seems sensible to get 4.0 bar
4. I've two pumped showers in the house, so occassionally I like both to operate at decent pressure if needed

My only concern with 4.0 bar pump is that the pressure is too strong for the taps, and even turning the tap on a small bit in the wash basin will shoot the water out onto the floor. Should this be a concern? Or unlikely to be a problem?

Sleeper12

metricspaces wrote:

If I go for 3.0 bar and pressure is not enough, then I'll have to pay for a 4.0 bar and pay a plumber twice. So for the sake of £60 extra, seems sensible to get 4.0 bar I've two pumped showers in the house, so occassionally I like both to operate at decent pressure if needed My only concern with 4.0 bar pump is that the pressure is too strong for the taps, and even turning the tap on a small bit in the wash basin will shoot the water out onto the floor. Should this be a concern? Or unlikely to be a problem?

I just checked mine out of pig iron. It's a 3 bar monsoon and I'm getting 23 litres per minute give or take with the shower head off

K.Flyer

I was a bit surprised to see the label rating the pump at 9 ltr / min. @ 1.5 bar as well.
According to the Stuart Turner web site the pump will deliver between 9 and 18 ltr / min, depending on resistance in the pipework, shower valve, shower head etc.
In other words an open pipe = greater flow rate, but lower pressure.
Might be worth checking the shower valve for partially blocked inlet strainers, its not uncommon problem.
Keep in mind, I have recently heard that Stuart Turner will not cover any warranty issues on non Irish spec pumps.

metricspaces

K.Flyer wrote: »

I was a bit surprised to see the label rating the pump at 9 ltr / min. @ 1.5 bar as well.
According to the Stuart Turner web site the pump will deliver between 9 and 18 ltr / min, depending on resistance in the pipework, shower valve, shower head etc.
In other words an open pipe = greater flow rate, but lower pressure.

I don't understand why previously you mentioned it was ok the I got almost 9 l/min with shower head off?

Surely with the shower head off I should be expecting a lot more than the minimum output of the pump?

The pump is approximately three metres from the shower.

If sleeper12 is getting 23 l/min with a 3bar, then if he stuck in a 2bar pump you'd expect roughly 15 l/min ? (3bar is 50% more pressure than 2 bar, 23 l/min is 50% more than 15 l/min).

The 3bar pump also says 9 l/min at 2.5bar. So I really don't understand why I should only be expecting 9 l/min on my 2bar pump.

So surely I should be expecting more than 9 l/min with shower head off?

K.Flyer wrote: »

Might be worth checking the shower valve for partially blocked inlet strainers, its not uncommon problem.

Thanks. I'll take a look. But not sure how to. Do I need to take the shower fixings on the wall apart?

K.Flyer wrote: »

Keep in mind, I have recently heard that Stuart Turner will not cover any warranty issues on non Irish spec pumps.

So the pumps sold in UK (for way cheaper) are not the same spec as the ones sold in Ireland?

Comparing the label on my pump to the info on the Stuart Turner website my pump looks identical.

metricspaces

Hmmm...I guess the relationship betwee
flow rate and pressure are not linear. So if sleeper12 dropped from a 3bar to a 2bar pump, his flow rate would not drop linearly. So my example is wrong? I don't know the equation to work it out correctly.

Sleeper12

metricspaces wrote:

So the pumps sold in UK (for way cheaper) are not the same spec as the ones sold in Ireland?

Modern Plant is the Irish agent for Stuart Turner. If you buy a Stuart Turner pump from the UK or Screwfix.ie then it hasn't gone through Modern Plant. If it doesn't go through them then they don't make any money on the pump. If Modern Plant don't make any money on the pump then they won't repair it under warranty. They only offer a warranty on pumps they sell. Buy a pump from the UK & you don't get the 5 years warranty. This is the case with any product from the UK with an Irish agent. Triton, Aqualisa, Salamander etc are a few more examples

metricspaces wrote:

If sleeper12 is getting 23 l/min with a 3bar, then if he stuck in a 2bar pump you'd expect roughly 15 l/min ? (3bar is 50% more pressure than 2 bar, 23 l/min is 50% more than 15 l/min).

Everything being equal. There can be many variations on setup. If one attic tank is higher than the other it will make a difference. Every elbow on the run slows it down.

When I tested mine I had the shower mixer valve halfway bet hit and cold to allow as much water through as possible. You can test it on cold only then hot only then both together. This might give you an indication that there's a problem with one pipe. Sometimes valves being fully open on the outside does not mean that they are fully open inside the valve. Sometimes you get faulty valves

There will be filters on the pump and on the hot & cold inlet on the shower itself. These need to be totally clean.

Sleeper12

metricspaces wrote:

Hmmm...I guess the relationship betwee flow rate and pressure are not linear. So if sleeper12 dropped from a 3bar to a 2bar pump, his flow rate would not drop linearly. So my example is wrong? I don't know the equation to work it out correctly.

If you have a half inch pipe & valve. The water pressure is let's say 2 bar. If you half close the valve you will reduce the flow rate but the pressure will still be 2 bar

K.Flyer

metricspaces wrote: »

I don't understand why previously you mentioned it was ok the I got almost 9 l/min with shower head off?

Because it was close to what the label said you should get.

Surely with the shower head off I should be expecting a lot more than the minimum output of the pump?
The pump is approximately three metres from the shower.

You will loose flow rates through pipes and shower valves, especially with fine strainers fitted.

The 3bar pump also says 9 l/min at 2.5bar. So I really don't understand why I should only be expecting 9 l/min on my 2bar pump.

So surely I should be expecting more than 9 l/min with shower head off?

As I said it comes down to resistance in pipework and valves.

Might be worth disconnecting one of the outlet pipes from the pump, preferably the cold one, and rate the water flow straight off the pump to see what the difference might be.
Also the feed hoses to the pump have strainers, I would double check them for any debris as well.

So the pumps sold in UK (for way cheaper) are not the same spec as the ones sold in Ireland?

Comparing the label on my pump to the info on the Stuart Turner website my pump looks identical.

I would agree that they are identical with the exception of the connection hoses, 3/4" and not 22mm.
They even say on their data sheet that the only difference is the hoses. So I imagine its market protection more than anything else.

metricspaces

Sleeper12 wrote: »

Modern Plant is the Irish agent for Stuart Turner. If you buy a Stuart Turner pump from the UK or Screwfix.ie then it hasn't gone through Modern Plant. If it doesn't go through them then they don't make any money on the pump. If Modern Plant don't make any money on the pump then they won't repair it under warranty. They only offer a warranty on pumps they sell. Buy a pump from the UK & you don't get the 5 years warranty. This is the case with any product from the UK with an Irish agent. Triton, Aqualisa, Salamander etc are a few more examples.

It's looking like I need to buy a new pump. The difference between UK and Irish price is a few hundred so I'm trying to weigh up my options.

If you buy from UK you must have some manufacturers warranty, same as buying any other product from UK/EU. Any idea what this is?

How would Modern Plant know you bought it outside Ireland? If a plumber buys and installs it for you you'd never know where he got it from?

Is it really a 5 year warranty? I mentioned that to someone and I remember vaguely being told it's really a 2 year warranty. I can't remember the details. Is there something particular about the warranty that means most people could not avail of it after two years?

metricspaces

Interesting. I just rang up Stuart Turner. They have told me that Modern Plant will come out to look at a Stuart Turner pump even if you bought the pump in the UK, the only requirement is that the pump has to be under warranty.

Does anyone have experience of Modern Plant refusing to look at a pump bought in the UK that is still under warranty?

Now, the person I was talking to from Stuart Turner said none of the online retailers in the UK would sell a pump with Irish fittings, and if I got the UK fittings separately afterwards it "may" invalidate the warranty.

Sleeper12

metricspaces wrote:

Does anyone have experience of Modern Plant refusing to look at a pump bought in the UK that is still under warranty?

Best option is to ring Modern Plant & ask. They won't know who you are so it won't effect any pump you might buy here or in the UK.

I can confirm that Triton definitely won't repair UK sourced showers. This includes triton models not intended for the Irish market but sold by Argos, B&Q, Screwfix and Homebase in Ireland. I also have emails from the Aqualisa agent stating that I have to provide an Irish receipt for any showers that I have fitted that needs repairing under the warranty. Up until recently my clients just showed them the receipt I gave.

Modern plant used to be the agent for Mira and never repaired UK mira showers. I'd be interested to hear what they say about UK Stuart Turner pumps

metricspaces

Sleeper12 wrote: »

Best option is to ring Modern Plant & ask. They won't know who you are so it won't effect any pump you might buy here or in the UK.

I rang Modern Plant and they said "Shower Doctors" are the ones that look after repairs (I didn't get around to calling them).

Whilst on to Modern Plant they gave me a price of 580e for a 4 bar monsoon pump. The UK price I have is 430e. A difference of 150e, guessing the 580e is retail price, trade I'm sure would be a little cheaper...so in the grand scheme of things it's not as big a saving as I was initially thinking.

K.Flyer

Spoke with M.P. about this..
If you phone up with a warranty issue call they will ask for the serial number and model code.
If the pump does not have ROI on the end of the model code number they will have to refer back to S.T. for authorisation to cover the warranty, which is at the discretion of S.T.
If the U.K. flexible hoses have been changed to Irish ones then most likely the warranty may be void as it has not been an authorised change to manufacturers specifications.
So..
If you are going to buy and fit a Stuart Turner pump sourced from the UK or N.I. make sure you fit the original hoses that come in the box to the pump.
But, Make sure you use 22mm copper pipe (or 15mm for the smaller plastic pump) to connect to the Stuart Turner hoses.
Then use whatever adaptors are required to connect back from this pipe to your original pipework.
There is no guarantee that S.T. or M.P. will cover the warranty, but at least with the correct hoses (which must be fitted almost dead straight up!!) they can't use the hoses against you to void the warranty.
Hope that somewhat clears up the question

metricspaces

I took at look at my pump and it does not have ROI at the end of the serial number. It also has a plastic attachment on the between the silver pipes of the pump and the copper pipe work. The end of the attachment connected to copper pipes has 22mm marked on it and the other end connected to the sliver pipes going into pump has 3/4 marked on it. Do I have a UK pump and and UK pipe work in my house (22mm)?

metricspaces

I just got a response back from Stuart Turner and they checked my serial number - my pump is a UK pump. Which I guess is good news as I can order a cheaper pump from the UK and fit it without any additional work required

Are there any potential negatives for me in the future with the house in general due to the fact that the builder used UK 22mm sized pipe work?

K.Flyer

metricspaces wrote: »

Are there any potential negatives for me in the future with the house in general due to the fact that the builder used UK 22mm sized pipe work?

Not really no, once you are aware of it you can mention it to anyone coming to do work for you.
There may sometimes be a small delay sourcing a component in metric, but adapters etc are available and a lot of parts come into the country with metric connections.

metricspaces

Fantastic. The only slight negative is it may be difficult for me to sell my current uk pump. Unless there's someone in ROI that has 22mm pipes, or is willing to adapt their 21mm pipes to fit my pump.

Of course I can stick on ebay and hope for a buyer up north or uk!

Sleeper12

metricspaces wrote:

Fantastic. The only slight negative is it may be difficult for me to sell my current uk pump. Unless there's someone in ROI that has 22mm pipes, or is willing to adapt their 21mm pipes to fit my pump.

I thought it wasn't working properly?

metricspaces

Sleeper12 wrote: »

metricspaces wrote:

@Sleeper12 you mentioned previously that a 2.0 bar pump should be putting out 14 l/min? But K.Flyer said my pump (based on the photo I shared of the label on it - see below) should only be putting out 9 l/min. That's obviously a big difference of 50%.

I was wrong. I was surprised myself when K.Flyer said 9 litres per minute but I don't for a second doubt his knowledge. I deal with self contained power showers and electric shower. I rarely deal with stand alone pumps

@Sleeper12 based on above I understood you were saying my pump putting out 8.6 l/min was working as expected?

Sleeper12

metricspaces wrote: »

@Sleeper12 based on above I understood you were saying my pump putting out 8.6 l/min was working as expected?

My fault. I thought you were replacing it because it was faulty. I'm mixing this with another thread

metricspaces

I did some more testing of the flow rate of bath\taps\shower in my house. Shower flow rate is extremely low. Does it look like I've a problem between the pump and the shower hose?

How I tested:

• Shower tested with shower head off.
• Cold\hot tested separately but no difference in flow rate.
• Left tap\shower running for a minute, then filled a bucket to 4 litre mark. Repeated 3 times (figures were almost identical each time).

In the main bathroom the flow rate of the bath is 66% faster than the shower. Surely something wrong here?

If I understand correctly, both the shower and the bath have the same diameter flexi pipes coming from the water pump. Copper piping is just added on at the T junction to connect up the tap\shower regulator - so the actual amount of copper pipe is a only a small fraction of the piping between the pump and the tap\shower? So how could the flow rate be so drastically different?

The ensuite shower is even worse again. It has almost the same flow rate as the mains coming into the kitchen cold tap. The ensuite is directly beside the main bathroom yet it drops 2 l/min flow rate?

If I could get my showers at the same flow rate as my bath, then I wouldn't need a new water pump I think.

K.Flyer

The bath taps will have a 3/4" connection and when the tap is fully open there is very little restriction on the flow rate. By comparison, shower connections will reduce down to 1/2" and usually have a gauze strainer and sometimes small little non-return valves to further reduce the flow rate.
The outlet of the shower is 1/2" and then its further reduced to the internal diameter of the hose.
So if the pipework is all exactly as it should be, then the flow rate from bath taps will always be higher due to the lesser restrictions.
You also find kitchen and basin taps fitted with small bore flexible connection hoses have much lower flow rates compared to older taps with 1/2" connections.

metricspaces

Thanks. So possibly these figures are ok? Even the drop of 2 l/min between the main bathroom shower and ensuite shower? Main bathroom is closer to the pump, the ensuite shower is about a further meter away.

I have someone coming to look at gauze strainers to see if they are blocked, so I'll see what that shows up.

They suggested that putting in a higher bar pump for the entire house may not be a great idea. The pressure in my taps is already high enough, but there is not enough copper pipe coming to my taps to put in pressure reducing valves, so would need to extend the piping on feeding every tap to give space to fit in the valve.

The extended pipes would be hidden, but it'll be messy and take up limited space I have in units under the taps. The pump is feeding 5 sinks, so 9 values in total.

The best job they said would be to run separate pipes to both the showers and run them off a separate pump. Bathrooms are tiled already, so I'm guessing this means ripping up at least the floor?

metricspaces

I got a Mira Atom shower valve to see if it made any difference. I see an increase of 27% in flow rate (from 10.4 l/min up to 13.2 l/min). But the end result from the shower head is not massively different. (There's no name on my valve, so no idea what brand it is)

Observed Flow Rates

Here are the results below from various tests. They are with the shower head off and max flow setting on the valve. Same hose used for both shower valves.



Expected Flow Rates of Mira Atom

Here is the expected flow rate of a Mira Atom EV valve. Based on this I'm seeing about 0.8bar at my shower hose (or maybe worse, as this graph is showing figures for the handset and I have the shower head off).


Mira Atom 19.6 l/min

One interesting thing with the Mira valve is when I put it at temperature setting 4 I see a flow rate of 19.6 l/min (temperature settings go from 1 to 10; where is 1 lowest cold and 10 max hot). I didn't notice this behaviour with my current valve.

I guess at temperature setting 4 the Mira valve is letting through full flow from both hot and cold. If I got this flow rate throughout the temperature settings I would be happy. But it drops off immediately back to the 13 l/min as soon as I move the setting up to level 5.

How to get close to 20 l/min?

To get close to the 20 l/min it looks like I would at least need to double my pressure? I currently have a 2 bar pump so that would mean going to 4 bar.

Looking at the pressure\flow rate chart from Mira.
* A flow rate of 13 l/min equates to about 0.8 bar
* A flow rate of 20 l/min equates to about 1.8 bar

So if I double the pressure of my pump, I hopefully double the pressure at the shower valve which would bring me from 0.8 bar at the valve to 1.6 bar, this would get me close to 20 l/min