bathroom plumbing
stevebubs - 30/4/08 at 05:10 PM
Right,
Finally plumbed dad's new bath in at the weekend (this one fits!!!)
However, the water pressure is absolutely appalling.
Problem 1 - Cold Water Supply
Never great in this room, it would appear that raising the taps by 3inches or so has reduced the cold water flow to the same sort of flow you'd
expect from a watering can.
Now, I'm assuming this lack of water flow is partly due to the lack of height difference between the loft tank and the top of the bath (about
8feet) but my house doesn't have much more than that and the water pressure is fine, so I'm guessing there's other contributing
factors. The feed pipes in both houses are 22mm diameter.
Only 2 things that spring to mind to explain the lack of pressure:
1) There's a restriction in the pipes somewhere (limescale buildup?).
2) The fact the water comes down into the airing cupboard, into the ground floor roof space and across the house before rising up out of the bathroom
floor is a factor.
Any ideas on the cold pressure problem? I would like to maintain the bath off the tank if I can, but it's a reasonably straightforward job to
relocate it to the rising main.
Problem 2 - Hot Water Supply
The pressure for this isn't great, but seems no worse than before. However, I would like to improve it.
Any suggestions? The boiler actually resides at ground level behind the living room fire (old Baxi - Bermuda?, I think)
TIA
Stephen
Rescued attachment house.JPG
MkIndy7 - 30/4/08 at 05:20 PM
Just a quick one... have U tried putting the old taps back on?
The new taps might be of a different type and more restrictive inside.. espescially as its effecting both hot and cold water, and the hot water was
probably restricted down in the first place.
owelly - 30/4/08 at 05:36 PM
If you havn't changed the height of the feed/expansion tank, then the pressure shouldn't have changed. The hot water tank is supplied from
the same header as the cold, the pressures should be the same. It's often the case that hot water tap pressure is a bit lower than that of the
cold because the hot water is cooling as its travelling on it's way to the tap! As both pipes are 22mm, I would say that there is either rubbish
at the bottom of your header tank which you've disturbed and it's blocking the outlet, or as previously mentioned, the taps are for a higher
pressure, with restrictive innards.
stevebubs - 30/4/08 at 05:37 PM
quote:
Originally posted by MkIndy7
Just a quick one... have U tried putting the old taps back on?
The new taps might be of a different type and more restrictive inside.. espescially as its effecting both hot and cold water, and the hot water was
probably restricted down in the first place.
did that this evening before I posted as my first reaction was that it may be the taps at fault.
The new tap is definitely a contributing factor. With just a flexi at the tap height, I we can half fill a saucepan from the cold tap in about 15
seconds. With the new taps it takes about 2 minutes.
The hot water on just a flexi half fills said saucepan in about half the time. With the tap installed, it takes about 30 seconds.
Conversely, both the hot and cold taps at my house will fill said saucepan full in about 7 seconds - making the flow rate about twice as high for hot
and 4x as high for cold...
stevebubs - 30/4/08 at 05:37 PM
quote:
Originally posted by owelly
If you havn't changed the height of the feed/expansion tank, then the pressure shouldn't have changed. The hot water tank is supplied from
the same header as the cold, the pressures should be the same. It's often the case that hot water tap pressure is a bit lower than that of the
cold because the hot water is cooling as its travelling on it's way to the tap! As both pipes are 22mm, I would say that there is either rubbish
at the bottom of your header tank which you've disturbed and it's blocking the outlet, or as previously mentioned, the taps are for a higher
pressure, with restrictive innards.
With no taps installed, the hot water flexi provides water at twice the rate of the cold....
westf27 - 30/4/08 at 05:39 PM
modern taps very restrictive unless they are the standard full bore wind up/down.You can fit a double ended pump that works on a pressure drop as you
open the tap.Nice pressurised water flow to all hot taps and low pressure cold fed outlets.
stevebubs - 30/4/08 at 05:42 PM
quote:
Originally posted by owelly
The taps are for a higher pressure, with restrictive innards.
I've a suspicion this will be a contributing factor...but not the root of all the problems.
The taps were supplied already fitted to the bath - is there anything we can do to "modify" them to derestrict them?
stevebubs - 30/4/08 at 05:43 PM
quote:
Originally posted by westf27
modern taps very restrictive unless they are the standard full bore wind up/down.You can fit a double ended pump that works on a pressure drop as you
open the tap.Nice pressurised water flow to all hot taps and low pressure cold fed outlets.
This sounds like it could be the solution - any suggestions given the house layout above?
billynomates - 30/4/08 at 05:53 PM
Fit a combi boiler, if the present boiler is getting old, and your dad has any thoughts that it maye need changing, just get on and do it.
Or maybe modify the current system so it is a pressurised system.
The locost solution - plan your baths well in advance.
Hellfire - 30/4/08 at 05:54 PM
I had a similar problem to this when I replumbed my Bathroom...
I found it to be the flexi's that I had used to connect to the taps from the fixed coppers. I hard wired them and the problem was cured.
I used to work in a company that manufactured taps and mixers and restrictions were never a problem. With that head of water you should have no
problems with no pressure. We hardly got any limescale on cold only systems...
If you have any flexi's - replace them or make sure they are not twisted or kinked.
Steve
eccsmk - 30/4/08 at 06:00 PM
^^ steve i think you mean hard piped 
indeed steve is correct if you've used flexi's they do restrict the flow alot as they are about 6mm core as apposed to copper tails which
are 10 - 15mm bore
hope you manage to get it sorted
stevebubs - 30/4/08 at 06:02 PM
quote:
Originally posted by billynomates
Fit a combi boiler, if the present boiler is getting old, and your dad has any thoughts that it maye need changing, just get on and do it.
Not an option, I'm afraid...
quote:
Or maybe modify the current system so it is a pressurised system.
How? Cold is easy to do, but what about the hot....
quote:
The locost solution - plan your baths well in advance.
TBH, if the new taps weren't restrictive to the point where the water literally dribbles out, we probably would have said "sod it" and
he'd had lived with the "not so ideal but workable" pressure available....as has been doing for the last god knows how many years...
[Edited on 30/4/08 by stevebubs]
stevebubs - 30/4/08 at 06:04 PM
quote:
Originally posted by eccsmk
^^ steve i think you mean hard piped
indeed steve is correct if you've used flexi's they do restrict the flow alot as they are about 6mm core as apposed to copper tails which
are 10 - 15mm bore
hope you manage to get it sorted
OK...so next test is to run a copper pipe up to the bath level....
The idea of inserting a pump to up the pressure appeals, though....
tjoh84 - 30/4/08 at 06:12 PM
the problem can come from 2many compersion fittings as it reduces the flow and traps air.
when i get this prob go in the loft you all ready have a risinf main feeding the tank.
tee off this pipe and disconect cold water feed and plumb to the mains 10 min job
stevebubs - 30/4/08 at 06:17 PM
quote:
Originally posted by tjoh84
the problem can come from 2many compersion fittings as it reduces the flow and traps air.
I can't believe 4 is too many? On the code, there is 1 x 22mm isolation valve, 1 x 22mm 90degree fitting, 1 x 22-15mm adapter and 1 x 15mm screw
fitting for the flexi
quote:
when i get this prob go in the loft you all ready have a risinf main feeding the tank.
tee off this pipe and disconect cold water feed and plumb to the mains 10 min job
Ready to go this route for the cold but what about the hot water....?
[Edited on 30/4/08 by stevebubs]
stevepj - 30/4/08 at 06:26 PM
to improve pressure on the cold side the easiest thing is to feed everything straight off the rising main, toilet fills faster - may need a restricter
in some cases, cleaning teeth is far nicer with fresh water rather than water from the storage tank full od sediment and the occasional dead thing!
as for the hot, you can increase the flow by increasing the drop from the storage tank into the hot water cylinder, but it will never be massive as
its only using gravity to cause the flow, so scrap the flexi on the hot and use 22mm copper right to the tap
stevebubs - 30/4/08 at 06:29 PM
quote:
Originally posted by stevepj
to improve pressure on the cold side the easiest thing is to feed everything straight off the rising main, toilet fills faster - may need a restricter
in some cases, cleaning teeth is far nicer with fresh water rather than water from the storage tank full od sediment and the occasional dead thing!
as for the hot, you can increase the flow by increasing the drop from the storage tank into the hot water cylinder, but it will never be massive as
its only using gravity to cause the flow, so scrap the flexi on the hot and use 22mm copper right to the tap
Increasing the drop isn't going to be possible, and, to be fair, I think the restrictiveness of the tap is still going to be an issue.
The idea of a pump sounds like it might be the right approach....just need to understand what/where/how....
MkIndy7 - 30/4/08 at 07:21 PM
I'm not sure your drawing is exactly correct.. The Bath water and the Boiler water should NOT be coming from the same tank!.
There should be 2 tanks in the loft, 1 small feed and expansion tank for the boiler and a larger tank that feeds the hot water cylinder and could also
feed the cold water to the bath taps etc.
You CANNOT just connect all the exsiting cold feeds from the tank direct to the mains if it feeds the hot water cylinder. It will not be designed to
take full mains pressure and there would also be no room for expansion of the water when heated (at prescent this should be done by a vent pipe back
upto and over the tank).
As suggested it might be best to remove the flexi's if possible, or maybe get some 22mm ones (so they will have a larger bore), or ask if there
are any "full flow" flexi's at a good plumbers merchants.
Also could any isolation valves on the cold water have snapped in the 1/2 closed position, also cheep ballafix valves can be very restrictive as they
only flow about 8mm and at low pressure this can have a big effect! also has said extra elbows etc.
stevebubs - 30/4/08 at 07:29 PM
quote:
Originally posted by MkIndy7
I'm not sure your drawing is exactly correct.. The Bath water and the Boiler water should NOT be coming from the same tank!.
There should be 2 tanks in the loft, 1 small feed and expansion tank for the boiler and a larger tank that feeds the hot water cylinder and could also
feed the cold water to the bath taps etc.
You CANNOT just connect all the exsiting cold feeds from the tank direct to the mains if it feeds the hot water cylinder. It will not be designed to
take full mains pressure and there would also be no room for expansion of the water when heated (at prescent this should be done by a vent pipe back
upto and over the tank).
As suggested it might be best to remove the flexi's if possible, or maybe get some 22mm ones (so they will have a larger bore), or ask if there
are any "full flow" flexi's at a good plumbers merchants.
Also could any isolation valves on the cold water have snapped in the 1/2 closed position, also cheep ballafix valves can be very restrictive as they
only flow about 8mm and at low pressure this can have a big effect! also has said extra elbows etc.
you're quite correct on the 2 header tanks, and the plumbing...
FWIW, the hot pipe also feeds the sink and the pressure is "OK". Not great, but OK.
I'm sure changing the flexis will make a huge difference but not big enough to overcome the bath tap issue...
To repeat what I've implied from previous comments....if it weren't for the restrictiveness of the bath tap, I don't think we'd
have an issue that we'd be bothered out....
So... once the flexis have been replaced with proper copper, the solution would appear to be
1) How to make the tap less restrictive
2) How to increase the pressure/flow to the taps (Pump??)
[Edited on 30/4/08 by stevebubs]
[Edited on 30/4/08 by stevebubs]
MkIndy7 - 30/4/08 at 07:41 PM
Maybe try and contact the manufacturers of the taps... there might be a restricter in them thats normally used when there on the mains but can be
removed in cases such as yours?.
Or if your really brave take them apart and have a look yourself, there may be part that could be filed away to give more flow or some massive
burr's left from the manufacturing process, you never know!.
There may also be filters on the inlet that you could remove either obvious as you look up the tap or inside somewhere.
stevebubs - 30/4/08 at 07:46 PM
quote:
Originally posted by MkIndy7
Maybe try and contact the manufacturers of the taps... there might be a restricter in them thats normally used when there on the mains but can be
removed in cases such as yours?.
Or if your really brave take them apart and have a look yourself, there may be part that could be filed away to give more flow or some massive
burr's left from the manufacturing process, you never know!.
There may also be filters on the inlet that you could remove either obvious as you look up the tap or inside somewhere.
Thanks - another jobs for this weekend!
The idea of also installing a pump really appeals also - not least for the fact that it would enable a decent power shower.
Given the location of the bath wrt the hot water boiler (boiler is on the ground floor at the other end of the house), what options do we have for
this?
ruskino80 - 30/4/08 at 07:47 PM
there are sometimes filters/aerators on the 'outlet spout' which can be removed to aid better flow-not a lot but a little
for a pump you will need a min of 50 gallons in the cold water storage tank in the loft check that first
pump £100
fittings £10
pipe £10
having a nice shower - priceless
[Edited on 30/4/08 by ruskino80]
stevebubs - 30/4/08 at 07:59 PM
quote:
Originally posted by ruskino80
there are sometimes filters/aerators on the 'outlet spout' which can be removed to aid better flow-not a lot but a little
for a pump you will need a min of 50 gallons in the cold water storage tank in the loft check that first
pump £100
fittings £10
pipe £10
having a nice shower - priceless
Tank is definitely big enough....what do I need to have/do for the install?
[Edited on 30/4/08 by stevebubs]
Peteff - 30/4/08 at 08:16 PM
Why is your cold tank for the boiler connected to your bath? It shouldn't be and as mentioned earlier your cold to your bath and wash basin
should come from the rising main. Stored water should not be used for tooth brushing only as a head for the hot water. Using it will reduce the volume
in the tank and lower the hot water flow. It can only come out of the hot tank as fast as it is replaced.
[Edited on 30/4/08 by Peteff]
ruskino80 - 30/4/08 at 08:16 PM
1.drain down tank
2.install 15 mm tank connector low down on side.
3.run 15mm pipe from this to pump(sat on floor next to cylinder)inlet (twin impellor pumps are inlet and outlet per side).
4.cut into 22 mm hot draw off of top of cylinder and t off in 15(or fit an essex flange)fit pipe to other side of pump.
5 pipe up outlets to your new shower valve
6 refill system and run draw offs to expell air
7 plug in pump
that should do it
be carefull though especially around the top of the cylinder part of the job things can go horribly wrong here!!!!
ps this is a very basic description-i shall not be held liable for any disasters!
hth rich
adam1985 - 30/4/08 at 08:17 PM
hi sounds to me like your problem is a air lock where the pipes come across the floor under your bath because the hot and cold should be the exact
same presure as they are both feed from the same tank so this rules out the taps being too restricted are the taps quarter turn ones or the old
fasioned screw ones to clear the air lock there are a couple of things you can try either put you mouth over the tap turn it on then try blow like mad
to clear it (very hard work) or get a hose pipe connect it to a mains tap (kithen or outside tap) and the other end to bath tap and force it out that
way
Wheels244 - 30/4/08 at 08:33 PM
Pressure (Bar) = Head ( in metres) divided by 10
In your case = approx 0.24 bar or 3.48 ILBs per sq in - Not a good start.
Next the 'inverse square law' - in brief if you double the diameter of a pipe you quarter the frictional loss, so you can get 4 times as
much water through it for the same given pressure. Conversely, if you half the the diameter, you will quarter the amount of water through it.
I cannot see why you would feed your cold water taps from a tank, plumb them direct into the feed for the house - you will get a much higher pressure
which will compensate for the smaller diameter pipe.
stevebubs - 30/4/08 at 08:36 PM
quote:
Originally posted by ruskino80
1.drain down tank
2.install 15 mm tank connector low down on side.
3.run 15mm pipe from this to pump(sat on floor next to cylinder)inlet (twin impellor pumps are inlet and outlet per side).
4.cut into 22 mm hot draw off of top of cylinder and t off in 15(or fit an essex flange)fit pipe to other side of pump.
5 pipe up outlets to your new shower valve
6 refill system and run draw offs to expell air
7 plug in pump
that should do it
be carefull though especially around the top of the cylinder part of the job things can go horribly wrong here!!!!
ps this is a very basic description-i shall not be held liable for any disasters!
hth rich
I'm lost - diagram?
adam1985 - 30/4/08 at 08:43 PM
10 years ago when nobody had combis about 95% of house ran the bath and basin of storage tanks there was no problem with them then and there still
aint converting to the mains will work if thats what you wanna do but the easist thing to do is is just clear the air lock
stevebubs - 30/4/08 at 08:48 PM
quote:
Originally posted by adam1985
10 years ago when nobody had combis about 95% of house ran the bath and basin of storage tanks there was no problem with them then and there still
aint converting to the mains will work if thats what you wanna do but the easist thing to do is is just clear the air lock
Am I reading the above right in that the easiest way to do that is to squirt mains water up from the taps to the tank?
eccsmk - 30/4/08 at 08:53 PM
generally if you either stick you wet n dry vacuum on the tap that will remove the air lock or a short length of garden hose put into the connector in
the tank and blow away
i havent read every post so you might have already been told this next bit but air locks only occur when a run of pipe rises and falls again
(this may be deleted if i find it written in a previous post)
HTH
stevebubs - 30/4/08 at 09:48 PM
quote:
Originally posted by adam1985
10 years ago when nobody had combis about 95% of house ran the bath and basin of storage tanks there was no problem with them then and there still
aint converting to the mains will work if thats what you wanna do but the easist thing to do is is just clear the air lock
Yep - his house dates from 1983 and mine 1984 (I think)
MkIndy7 - 30/4/08 at 11:29 PM
quote:
Originally posted by stevebubs
quote:
Originally posted by MkIndy7
Just a quick one... have U tried putting the old taps back on?
The new taps might be of a different type and more restrictive inside.. espescially as its effecting both hot and cold water, and the hot water was
probably restricted down in the first place.
did that this evening before I posted as my first reaction was that it may be the taps at fault.
The new tap is definitely a contributing factor. With just a flexi at the tap height, I we can half fill a saucepan from the cold tap in about 15
seconds. With the new taps it takes about 2 minutes.
The hot water on just a flexi half fills said saucepan in about half the time. With the tap installed, it takes about 30 seconds.
Conversely, both the hot and cold taps at my house will fill said saucepan full in about 7 seconds - making the flow rate about twice as high for hot
and 4x as high for cold...
Just reading this back it sums it up completely.. no need to get carried away with airlocks etc.. the taps are just of poor and restrictive design.
Taps can range from £10 a pair to the absoloute crazyness, what looked like 2 normal pairs of taps even with our works discount went from £10 for the
cheepest to £40 for some others and even onto over £100 a pair for some others. Allowing for shinier chrome, packageing and whatever else there must
be a difference in the design construstion and styling etc.
Without the taps and just the flexi's connected there's a pretty good flow of water.. it just all goes wrong after that!
Schrodinger - 2/5/08 at 10:49 PM
Having recently been looking for a shower and taps, I found that a lot of taps these days require at least 1bar, where did your bath/taps come from?
stevebubs - 3/5/08 at 12:01 PM
www.the-direct-group.co.uk
Is the corner whirlpool bath - comes complete with taps etc already fitted...and you're quite right - it specifies 1 bar pressure...
Have been out and bought a salamander CT75 from screwfix. Will be fitting it tomorrow.
[Edited on 3/5/08 by stevebubs]
stevebubs - 4/5/08 at 05:35 PM
Right - while you lot have been getting rained on at Stoneleigh, I've had my head under a bath getting rained on there.
Thankfully putting the CT75 pump in the airing cupboard did the trick - now have a nice steady flow of water into the bath!!
Thanks for all your help!!!
