Plumbing questions - bath mixer/shower taps
Discussion
Sorry in advance, this might be slightly rambling as I have a series of queries...
SWMBO would like a shower over the bath in the main bathroom. This would be for occasional use only, so we don't want a massive project. We've found ourselves looking at mixer taps with a proper shower head mounted to the wall, rigid or flexi (not the type with a head on a short hose for rinsing down the bath).
She is particularly drawn to this Mira one which is thermostatic as well.
However, I'm not sure this is as simple as it looks...
Happily, our tap centers are 180mm, which is about the only thing in this house that appears to be a modern standard size!
First off, how do you check the water pressures?
And then the instructions for that shower say "Mixed gravity and mains supplies are not recommended"... which I think is what we've got. We have a hot water tank upstairs with 2 tanks in the attic, that bath fills quickly with hot water (in fact, I'm for this thermostatic one as she tends to run a bath by using all the hot water, then letting a load out so she can get enough cold in there...), and then very good pressure on the cold water side, which is definitely mains fed. In fact we can't open the stopcock in the road all the way for the pipes start banging. I have noticed that on the only mixer tap in the house (kitchen sink) that the hot water flow is easily overwhelmed by the cold and this worries me for a mixer shower.
Is it possible to get a restrictor for the cold water feed to the bath?
Or could the isolation valve built into that tap be used to do that on the cold side (redneck bodge approach)?
And finally, if we don't go for that Mira one, there appear to be approximately 1000 almost identical versions of similar things without the thermostat... are there any other brands you guys would recommend us to look at (or ones to avoid!)?
Thanks in advance
SWMBO would like a shower over the bath in the main bathroom. This would be for occasional use only, so we don't want a massive project. We've found ourselves looking at mixer taps with a proper shower head mounted to the wall, rigid or flexi (not the type with a head on a short hose for rinsing down the bath).
She is particularly drawn to this Mira one which is thermostatic as well.
However, I'm not sure this is as simple as it looks...
Happily, our tap centers are 180mm, which is about the only thing in this house that appears to be a modern standard size!
First off, how do you check the water pressures?
And then the instructions for that shower say "Mixed gravity and mains supplies are not recommended"... which I think is what we've got. We have a hot water tank upstairs with 2 tanks in the attic, that bath fills quickly with hot water (in fact, I'm for this thermostatic one as she tends to run a bath by using all the hot water, then letting a load out so she can get enough cold in there...), and then very good pressure on the cold water side, which is definitely mains fed. In fact we can't open the stopcock in the road all the way for the pipes start banging. I have noticed that on the only mixer tap in the house (kitchen sink) that the hot water flow is easily overwhelmed by the cold and this worries me for a mixer shower.
Is it possible to get a restrictor for the cold water feed to the bath?
Or could the isolation valve built into that tap be used to do that on the cold side (redneck bodge approach)?
And finally, if we don't go for that Mira one, there appear to be approximately 1000 almost identical versions of similar things without the thermostat... are there any other brands you guys would recommend us to look at (or ones to avoid!)?
Thanks in advance
defblade said:
Sorry in advance, this might be slightly rambling as I have a series of queries...
SWMBO would like a shower over the bath in the main bathroom. This would be for occasional use only, so we don't want a massive project. We've found ourselves looking at mixer taps with a proper shower head mounted to the wall, rigid or flexi (not the type with a head on a short hose for rinsing down the bath).
She is particularly drawn to this Mira one which is thermostatic as well.
However, I'm not sure this is as simple as it looks...
Happily, our tap centers are 180mm, which is about the only thing in this house that appears to be a modern standard size!
First off, how do you check the water pressures?
SWMBO would like a shower over the bath in the main bathroom. This would be for occasional use only, so we don't want a massive project. We've found ourselves looking at mixer taps with a proper shower head mounted to the wall, rigid or flexi (not the type with a head on a short hose for rinsing down the bath).
She is particularly drawn to this Mira one which is thermostatic as well.
However, I'm not sure this is as simple as it looks...
Happily, our tap centers are 180mm, which is about the only thing in this house that appears to be a modern standard size!
First off, how do you check the water pressures?
For mains pressure - this on an outside tap
https://www.screwfix.com/p/monument-tools-mains-wa...
defblade said:
And then the instructions for that shower say "Mixed gravity and mains supplies are not recommended"... which I think is what we've got. We have a hot water tank upstairs with 2 tanks in the attic, that bath fills quickly with hot water (in fact, I'm for this thermostatic one as she tends to run a bath by using all the hot water, then letting a load out so she can get enough cold in there...), and then very good pressure on the cold water side, which is definitely mains fed. In fact we can't open the stopcock in the road all the way for the pipes start banging. I have noticed that on the only mixer tap in the house (kitchen sink) that the hot water flow is easily overwhelmed by the cold and this worries me for a mixer shower.
Yep and that's why it's not recommendeddefblade said:
Is it possible to get a restrictor for the cold water feed to the bath?
Or could the isolation valve built into that tap be used to do that on the cold side (redneck bodge approach)?
<snip>
How difficult would it be to run a feed from you CW tank to the bath tap so the shower had equal Hot and Cold pressures? Across the top in the loft and then down??Or could the isolation valve built into that tap be used to do that on the cold side (redneck bodge approach)?
<snip>
Might stop Mrs Defblade from wasting HW to drain when filling the bath because you could add HW and a smidge of CW at the same time although that also does indicate that you may be heating water to a higher temp that you really need
defblade said:
I have noticed that on the only mixer tap in the house (kitchen sink) that the hot water flow is easily overwhelmed by the cold and this worries me for a mixer shower.
But if the shower temp is thermostatically controlled, wouldn't that sort it out?I have a mains cold feed and gravity hot. For the bath I deal with this by having the hot tap fully open but the cold tap only a bit. For the shower I have an Aqualisa Axis which has a built-in pump.
The shower in the ensuite has its own internal pump and a tank above it in the loft. We're trying to avoid running new pipes or electric if we can...
And, yes, I run hot full and cold less with separate taps, but it does seem like the cold actually blocks (or maybe back-pressures?) the hot on the mixer downstairs unless you're very careful.
And, yes, I run hot full and cold less with separate taps, but it does seem like the cold actually blocks (or maybe back-pressures?) the hot on the mixer downstairs unless you're very careful.
The majority of showers (& bathroom taps) are designed to operate with equal pressures from hot & cold water supplies. If they’re installed with gravity hot & mains cold, they’ll probably work to some degree, but not effectively & in many cases not at all, with the cold overwhelming the hot.
You can calculate hot pressure - something like 10 metre head of water is 1 bar (approx), look it up for exact figure. You could fit a pressure reducing valve to the cold mains pipe - turning down the stop cock will reduce flow, not pressure.
Ideal solution would be a cold supply run from the tank in the loft.
You can calculate hot pressure - something like 10 metre head of water is 1 bar (approx), look it up for exact figure. You could fit a pressure reducing valve to the cold mains pipe - turning down the stop cock will reduce flow, not pressure.
Ideal solution would be a cold supply run from the tank in the loft.
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