Water pump adjustable pressure?

Sleeper12

I want to get the old valve off the ensuite to test with the Mira valve, but there are two screws in the bracket holding the vertical pipe in place and it looks like I need a special screw bit to take it apart. Anyone have any ideas?

You are looking for an Allen key

With a manual shower you can install it with the hot & cold swapped around & you'd turn it to cold on the dial for hot & hot for cold. Hooking the pipes to a thermostatic shower crossed over like that messes with it's brains & it wont function correctly

John.G

Sleeper12 wrote: »

You are looking for an Allen key

With a manual shower you can install it with the hot & cold swapped around & you'd turn it to cold on the dial for hot & hot for cold. Hooking the pipes to a thermostatic shower crossed over like that messes with it's brains & it wont function correctly

The tests were done with a cold "hot water" cylinder so I suppose it may not have made much difference to the flow tests but the thermostatic shuttle certainly wouldnt work properly. Is hot & cold normally stamped on the mixer barrel water inlet connections?.

Sleeper12

John.G wrote: »

The tests were done with a cold "hot water" cylinder so I suppose it may not have made much difference to the flow tests but the thermostatic shuttle certainly wouldnt work properly. Is hot & cold normally stamped on the mixer barrel water inlet connections?.

Different manufacturers do different things. Many mark hot & cold. Others don't. It will always be it the installation booklet. Each manufacturer have the Hot & Cold on the same side on all their models. So swapping a Mira for a Mira the pipe will be the same

metricspaces

Existing Shower Valve

Here's my shower valve from the main bathroom



Here's the connection for the hose, no restrictor there.


Here's the connection for the inlet, no restrictor there either it seems?



Mira Atom Valve

Here's the inlet valve from the new Mira Atom shower valve, there is something in there. Is it a restrictor? I didn't easily come out and I didn't want to damage it so I didn't try to hard.

metricspaces

Sleeper12 wrote: »

You are looking for an Allen key

Thanks! If I get something like this from B&Q I'm guessing one of them will fit https://www.diy.com/departments/carbon-steel-hex-key-keyring-set-0/1801911_BQ.prd ?

Just saw they give the mm sizes on the B&Q site...I'll measure mine

Sleeper12

metricspaces wrote: »

Thanks! If I get something like this from B&Q I'm guessing one of them will fit https://www.diy.com/departments/carbon-steel-hex-key-keyring-set-0/1801911_BQ.prd ?

Just saw they give the mm sizes on the B&Q site...I'll measure mine

thats them

John.G

metricspaces wrote: »

I measured the hot tap in the kitchen with the pump turned off. Flow rate was 3.3 LPM. How does this sound?

I want to get the old valve off the ensuite to test with the Mira valve, but there are two screws in the bracket holding the vertical pipe in place and it looks like I need a special screw bit to take it apart. Anyone have any ideas?






I didn't get time to fully test both valves in main bathroom with hot water. I'll do that at the weekend at post up complete set of figures.

One problem I noticed though is that my hot\cold pipes are the wrong way around in the main bathroom, so I had to turn the valve upside down to get it to work. Other than being a bit of a pain as you can't read the settings on the valve now as they are upside down, will this cause me any problem?

How did you know that they are the wrong way round?

John.G

metricspaces wrote: »

Existing Shower Valve

Here's my shower valve from the main bathroom



Here's the connection for the hose, no restrictor there.


Here's the connection for the inlet, no restrictor there either it seems?



Mira Atom Valve

Here's the inlet valve from the new Mira Atom shower valve, there is something in there. Is it a restrictor? I didn't easily come out and I didn't want to damage it so I didn't try to hard.

There seems to be a restrictor in both those pictures above (isnt there a white plastic ball in both?) except that one will need a socket or box spanner to remove it and the other will need a circlip pliers to remove it. If theres a restrictor on the inlet then there is IMPO one in the outlet as well.
Its funny but they look like non return (check) valves to me.
If you press them with your finger you should find that they are spring loaded.

metricspaces

John.G wrote: »

There seems to be a restrictor in both those pictures above (isnt there a white plastic ball in both?)

Yep, it seems to be a plastic ball type thing. So I should just get this out?

John.G wrote: »

If you press them with your finger you should find that they are spring loaded.

Definitely my original valve it seems to be a ball type thing that I can push in and it pops back out.

metricspaces

John.G wrote: »

How did you know that they are the wrong way round?

In the main bathroom, they are the wrong way around as when I put the Mira valve on the correct way around (so you can read the heat settings and on\off marker) all I got out was hot water. When I turned it upside down I was able to regulate the temperature and change from cold to hot.

I haven't had a chance to test the original valve in the main bathroom with hot water. So maybe the pipes are the correct way around for my original valve. Or do all manufacturers have the hot\cold on the same side?

You were asking about my flow rate from hot tap in kitchen with pump off. How does my 3.3 LPM sound to you?

John.G

metricspaces wrote: »

Yep, it seems to be a plastic ball type thing. So I should just get this out?



Definitely my original valve it seems to be a ball type thing that I can push in and it pops back out.

Just to be clear on the above, the valve with BC on it, is there a plastic ball in this one as well that you can press in and out? or am I just looking at the back of the bar??. and as I stated before its quite possible that this is fitted to both cold & hot water inlets, I would still remove them even if they are check valves as they will have a restrictive effect as distinct from a flow regulator which when fitted in the bar discharge connection is effectively an orifice plate and is designed specifically for that purpose. I do know that some people do remove the check valves on the anti scald (thermostatic) valve used with solar systems especially to improve the flowrate in gravity fed systems, they may not have a huge effect with a pumped system as someone above posted earlier but one wont know until they are removed, they can always be replaced.
Will get back to you later re other posts.

John.G

metricspaces wrote: »

In the main bathroom, they are the wrong way around as when I put the Mira valve on the correct way around (so you can read the heat settings and on\off marker) all I got out was hot water. When I turned it upside down I was able to regulate the temperature and change from cold to hot.

I haven't had a chance to test the original valve in the main bathroom with hot water. So maybe the pipes are the correct way around for my original valve. Or do all manufacturers have the hot\cold on the same side?

You were asking about my flow rate from hot tap in kitchen with pump off. How does my 3.3 LPM sound to you?

You got 6.7 LPM hot so assuming 0.6 Bar gravity head, the pump total head required is 0.6*(6.7/3.3)^2 - 0.6 = 1.87 bar which from the "2Bar" pump curves seems spot on so the pump (on the hot end anyway) seems OK.

John.G

metricspaces wrote: »

Yep, it seems to be a plastic ball type thing. So I should just get this out?



Definitely my original valve it seems to be a ball type thing that I can push in and it pops back out.

Re: Hot & cold water connections, if you open the link to the Triton Dove you will see that the hot connection is on the left as you are looking at the wall and the cold is on the right, if you look at the spares list you will see both non return valves and at least one restrictor which may be just fitted (on this mode) on the hot water inlet?. I think Sleeper12 said all Triton Bar showers have the hot&cold on the same side but that doesnt mean that it applies to other makes. I'd say that the plastic balls in your other photos are check valves.
https://www.wolseley.co.uk/wcsstore7.00.805.1036/ExtendedSitesCatalogAssetStore/images/products/AssetPush/DTP_AssetPushHighRes/std.lang.all/ti/on/Triton_DoveEcoMixer_Installation.pdf

Sleeper12

The photos with the white balls are non return valves. These shouldn't be removed as they are part of the hot /cold mixing process. Shower won't function correctly without them

John.G

Sleeper12 wrote: »

The photos with the white balls are non return valves. These shouldn't be removed as they are part of the hot /cold mixing process. Shower won't function correctly without them

OK, to summarise then, all Metricspaces can do is, (1) make sure that there are no flow restrictors in any of his showers either in one or both of the water inlets or in the outlet from the shower bar, (2) Make sure that the water connections are orientated correctly, (3) put the showerheads back on, (4) ensure that his hot water cylinder is at its normal temperature, nominally 60C, and then run all his tests again, hot,cold and mixed. OPs might like to add to this.

Sleeper12, you got 23 LPM (mixed) with a 3 Bar pump and the showerhead off, any idea what your normal flowrate is, with the showerhead on?.

John.G

Sleeper12 wrote: »

The photos with the white balls are non return valves. These shouldn't be removed as they are part of the hot /cold mixing process. Shower won't function correctly without them

OK, to summarise then, all Metricspaces can do is, (1) make sure that there are no flow restrictors in any of his showers either in one or both of the water inlets or in the outlet from the shower bar, (2) Make sure that the water connections are orientated correctly, (3) put the showerheads back on, (4) ensure that his hot water cylinder is at its normal temperature, nominally 60C and then run all his tests again, hot,cold and mixed. OPs might like to add to this.

Sleeper12, you got 23 LPM (mixed) with a 3 Bar pump and the showerhead off, any idea what your normal flowrate is, with the showerhead on?.

Sleeper12

John.G wrote:

Sleeper12, you got 23 LPM (mixed) with a 3 Bar pump and the showerhead off, any idea what your normal flowrate is, with the showerhead on?.

I haven't tested but I have have a rain water head so I have wouldn't expect much of a reduction in flow. I only tested without the head cos its easier to get into a litre jug from the hose itself.
My tank is raised about a metre. I run 3/4 inch pipe to the pump and the pump is inches from the shower valve. There are no elbows on my system. I designed my system for optimum pusure/flow

John.G

Sleeper12 wrote: »

I haven't tested but I have have a rain water head so I have wouldn't expect much of a reduction in flow. I only tested without the head cos its easier to get into a litre jug from the hose itself.
My tank is raised about a metre. I run 3/4 inch pipe to the pump and the pump is inches from the shower valve. There are no elbows on my system. I designed my system for optimum pusure/flow

I was wondering why you were doing the tests without the showerhead!.

metricspaces

John.G wrote: »

You got 6.7 LPM hot so assuming 0.6 Bar gravity head, the pump total head required is 0.6*(6.7/3.3)^2 - 0.6 = 1.87 bar which from the "2Bar" pump curves seems spot on so the pump (on the hot end anyway) seems OK.

I'm trying to understand this. Where does the 0.6 bar come from?

0.6bar is the pressure needed to raise water 6m. Is the assumption that my hot water is coming from 6m above the tap in the kitchen?

My ceiling height downstairs is 2.4m. Tap is probably close to 1m off the ground. Top of the hot water tank is about 1.5m off the ground upstairs. So that leaves around 3m head height which would be 0.3 bar?

metricspaces

John.G wrote: »

OK, to summarise then, all Metricspaces can do is, (1) make sure that there are no flow restrictors in any of his showers either in one or both of the water inlets or in the outlet from the shower bar, (2) Make sure that the water connections are orientated correctly, (3) put the showerheads back on, (4) ensure that his hot water cylinder is at its normal temperature, nominally 60C and then run all his tests again, hot,cold and mixed.

Thanks! I will test again with both shower valves in both bathrooms at weekend and post up my figures.

From the photos I uploaded it looks like I don't have any restrictors?

When I turn the Mira valve upside down to get it working, is there any negative consequence here other than it's hard to read the markings on it ?

John.G

metricspaces wrote: »

I'm trying to understand this. Where does the 0.6 bar come from?

0.6bar is the pressure needed to raise water 6m. Is the assumption that my hot water is coming from 6m above the tap in the kitchen?

My ceiling height downstairs is 2.4m. Tap is probably close to 1m off the ground. Top of the hot water tank is about 1.5m off the ground upstairs. So that leaves around 3m head height which would be 0.3 bar?

Its the distance from the top of your cold water tank to your tap that gives the gravity head as the cold water tank feeds the hot water tank and then the hot water tap, so what do you reckon is the distance from water level in the cold water storage tank to the cold tap? and we can do the calcs again.

John.G

metricspaces wrote: »

Thanks! I will test again with both shower valves in both bathrooms at weekend and post up my figures.

From the photos I uploaded it looks like I don't have any restrictors?

When I turn the Mira valve upside down to get it working, is there any negative consequence here other than it's hard to read the markings on it ?

No it doesnt look as if you have any restrictors but check everything again.

"Upside down" Mira valve, as long as the water inlets are correct I cant see how it would make any difference.

John.G

John.G wrote: »

Its the distance from the top of your cold water tank to your tap that gives the gravity head as the cold water tank feeds the hot water tank and then the hot water tap, so what do you reckon is the distance from water level in the cold water storage tank to the cold tap? and we can do the calcs again.

If I use an educated guess of 4M or 0.4bar from your cold tank water level to the tap, then the calcs give a flowrate of 7.2 LPM (vs a measured 6.7) from the 2 Bar pump so I think its reasonable to conclude that the Pump hot end at least is performing OK?.

metricspaces

I did some more testing of flow rates at the weekend, see results below. I think the conclusion is that a combination of (a) having hot water! and (b) using the Mira valve results in expected performance from my 2 bar pump - I get 20 LPM in both showers

So it looks like I should throw my existing two valves in the bin, keep my Mira valve for main bath, and buy a new Mira diverter valve for the ensuite. Sound like a good plan?

Results



How I tested

I timed filling a 4 litre bucket, repeated three times and took average.

Turned on shower, left running for few seconds, filled bucket, turned off shower. Repeated.

I had the shower valve set to the max heat setting before you have to press the button in to make it hotter. On the Mira valve this is setting 7 out of 10. There are no numbers on the existing shower valve to tell what heat setting this is.

I used the same shower hose with both valves. The shower head was removed for all tests.

Observation

Interestingly, the flow rate in main bath is lower with the old valve. I think this valve is not working correctly though, it was not possible for me to get completely cold water out of it.

My figures for the "old valve" in main bath and ensuite are for the valves that existed in these rooms before the Mira - i.e. I didn't take the old valve off the wall in the main bath and put it into the ensuite for testing (I was all tested out at that stage!). But they are they same brand, they look identical apart from the fact that the ensuite has a diverter on it for rain shower head.

There's a 3% reduction in flow rate between the main bath and the ensuite for the Mira valve. But this is so small it not really worth talking about.

metricspaces

John.G wrote: »

If I use an educated guess of 4M or 0.4bar from your cold tank water level to the tap, then the calcs give a flowrate of 7.2 LPM (vs a measured 6.7) from the 2 Bar pump so I think its reasonable to conclude that the Pump hot end at least is performing OK?.

I measured this distance. It is approx 4.785 M, give or take a few cm! So it sounds like all is good here?

John.G

metricspaces wrote: »

I did some more testing of flow rates at the weekend, see results below. I think the conclusion is that a combination of (a) having hot water! and (b) using the Mira valve results in expected performance from my 2 bar pump - I get 20 LPM in both showers

So it looks like I should throw my existing two valves in the bin, keep my Mira valve for main bath, and buy a new Mira diverter valve for the ensuite. Sound like a good plan?

Results



How I tested

I timed filling a 4 litre bucket, repeated three times and took average.

Turned on shower, left running for few seconds, filled bucket, turned off shower. Repeated.

I had the shower valve set to the max heat setting before you have to press the button in to make it hotter. On the Mira valve this is setting 7 out of 10. There are no numbers on the existing shower valve to tell what heat setting this is.

I used the same shower hose with both valves. The shower head was removed for all tests.

Observation

Interestingly, the flow rate in main bath is lower with the old valve. I think this valve is not working correctly though, it was not possible for me to get completely cold water out of it.

My figures for the "old valve" in main bath and ensuite are for the valves that existed in these rooms before the Mira - i.e. I didn't take the old valve off the wall in the main bath and put it into the ensuite for testing (I was all tested out at that stage!). But they are they same brand, they look identical apart from the fact that the ensuite has a diverter on it for rain shower head.

There's a 3% reduction in flow rate between the main bath and the ensuite for the Mira valve. But this is so small it not really worth talking about.

I can't see these properly on my free wifi at the airport but did you do tests with shower head on and if not why not

metricspaces

John.G wrote: »

I can't see these properly on my free wifi at the airport but did you do tests with shower head on and if not why not

I tested with shower head off.

Both valves have different shower heads, so removing the shower head allows for better comparison of shower valves, and removes one variable from determining if pump is operating as expected.

I could test again with shower head on. Mira head on both valves, old head on both valves etc...but not sure it will tell me much more with regards determining if my pump\valves are operating as expected.

Sleeper12

metricspaces wrote:

Interestingly, the flow rate in main bath is lower with the old valve. I think this valve is not working correctly though, it was not possible for me to get completely cold water out of it.

This would suggest that the dial isn't sitting in the correct position. This might make the result of any tests on this valve redundant. Not that it matters if you are replacing it anyway

metricspaces

Sleeper12 wrote: »

This would suggest that the dial isn't sitting in the correct position. This might make the result of any tests on this valve redundant. Not that it matters if you are replacing it anyway

Thanks. The shower in the ensuite (same make) is only getting 13 LPM and the Mira getting 20 LPM. So if there's nothing I can do to get my existing valve to 20 LPM (i.e. no restrictors to remove etc.) then only option I see is to get a new valve in both bathrooms?

Sleeper12

metricspaces wrote:

Thanks. The shower in the ensuite (same make) is only getting 13 LPM and the Mira getting 20 LPM. So if there's nothing I can do to get my existing valve to 20 LPM (i.e. no restrictors to remove etc.) then only option I see is to get a new valve in both bathrooms?

20 lmp is a lot for a two bar pump. Can't argue with that