Can you plumb hot water supply into an electric shower ?

dnme · 06-12-2010 03:42PM #1

Just wondering if you can plumb hot water supply into an electric shower ?

I have a Mira Elite St, during this cold weather, taking showers is miserable as it struggles to heat the extra cold water to a bearable temp. I often wondered if you could plumb the hot water supply into it.

I more or less have constant hot water here in the tank from using the central heating. If I could plumb the hot water supply into my shower, it would have to far less work to heat the water during showers, thus making it cheaper, more efficient, warmer showers etc.

Any thoughts?

Joey the lips · 06-12-2010 04:01PM

Firstly to answer your question..... No!

Your theory is not sound and actually dangerous.

As the mira elite is not thermostatic in theory you can scald yourself or others quite easy.

However if you have that constant supply of hot water then perhaps you should switch your mira elite to a power shower...

mullingar · 06-12-2010 04:05PM

+1 on what Joey said ^^

A domestic hot water supply can often reach 50C+, so ask yourself how are you going to cool that water??

Buy a new MIXER shower if you want to use the existing HW

dnme · 06-12-2010 05:03PM

Thanks guys,

I guess what I was really after was having the best of all worlds. So ideally, plumbing the hot and cold water into the power shower. That way it's never too hot, you are getting the benefit of the existing hot water and saving money. AND in the summer you don't have to pre-heat water before your shower.

I mean, surely there's a smart mixer valve that can handle this. If I turn it to cold, it gives me the cold feed. If I turn it up to hot, it gives me the hot feed plus and power it needs to add the extra required heat.

It just kills me the inefficiency of it all. Anyway I take your points and many thanks.

Joey the lips · 06-12-2010 05:19PM

dnme wrote: »

Thanks guys,
I mean, surely there's a smart mixer valve that can handle this. If I turn it to cold, it gives me the cold feed. If I turn it up to hot, it gives me the hot feed plus and power it needs to add the extra required heat.

It just kills me the inefficiency of it all. Anyway I take your points and many thanks.

In the words of the late lesley neilson... Dont call me shirley.....

It all depends what you want to do.

There are many showers for many things but not one shower for everything...

You want a shower that can

Pump the water

Heat the water

Control the temperature

at a fast rate..

The best solution out there is actually what you have but its working slower because the temp needs to be raised higher....

heinbloed · 06-12-2010 10:22PM

The max. allowed feed-in temperature can be got from the installation manual. Usually around 20 degrees Celsius for most makes, a no-brainer to install a mixing valve between shower and DHW source....

There are many electric showers nowadays available which are designed to take warm/hot water.
Check the www. for your " favorite brand plus solar".

Mira has one of these 'solar' showers as well, you can get it at most Irish plumbing centers. See their home page for further technical details.

Joey the lips · 06-12-2010 11:58PM

heinbloed wrote: »

The max. allowed feed-in temperature can be got from the installation manual. Usually around 20 degrees Celsius for most makes, a no-brainer to install a mixing valve between shower and DHW source....

There are many electric showers nowadays available which are designed to take warm/hot water.
Check the www. for your " favorite brand plus solar".

Mira has one of these 'solar' showers as well, you can get it at most Irish plumbing centers. See their home page for further technical details.

I would be wery of using a blending valve on a pumped shower.. The reduction in water flow that occurs with them would not be healthy for the shower...

However the idea sounds interesting... It could actually reduce energy consumption if it was a workable idea.

groodyman · 31-10-2015 11:30PM

I just tried this today. Supplied my electric Triton T90si 8.5 KW from my hot water cylinder. Took 10 minutes to switch the pipes over.

I then was able to run the shower at maximum pressure and a reduced heater setting. Worked a treat. You can adjust the heater setting depending on the water temprature in the cylinder. If the cylinder water is hot enough the the electric shower heater setting can be set to cold and you still get max pressure showering with the temprature of the water in the cylinder.

The trick here is to set your cylinder thermostat so that it will not to heat the water hot. Just luke warm.
(Remember the electric shower cannot cool water)

I have mine on a daily timer. Heats the cylinder water for 30 mins every 24 hours. This keeps the cylinder water luke warm.

Now I have full pressure from my electric shower even in very cold weather. And I'm using less power to run the electric shower.

Dtp1979 · 01-11-2015 12:01AM

groodyman wrote: »

I just tried this today. Supplied my electric Triton T90si 8.5 KW from my hot water cylinder. Took 10 minutes to switch the pipes over.

I then was able to run the shower at maximum pressure and a reduced heater setting. Worked a treat. You can adjust the heater setting depending on the water temprature in the cylinder. If the cylinder water is hot enough the the electric shower heater setting can be set to cold and you still get max pressure showering with the temprature of the water in the cylinder.

The trick here is to set your cylinder thermostat so that it will not to heat the water hot. Just luke warm.
(Remember the electric shower cannot cool water)

I have mine on a daily timer. Heats the cylinder water for 30 mins every 24 hours. This keeps the cylinder water luke warm.

Now I have full pressure from my electric shower even in very cold weather. And I'm using less power to run the electric shower.

Nice idea but heating your water in your cylinder to "warm" is very dangerous. Google legionaries disease.
You MUST heat stored hot water to a minimum 55 degrees Celsius

01-11-2015 12:05AM

groodyman wrote: »

I just tried this today. Supplied my electric Triton T90si 8.5 KW from my hot water cylinder. Took 10 minutes to switch the pipes over.

I then was able to run the shower at maximum pressure and a reduced heater setting. Worked a treat. You can adjust the heater setting depending on the water temprature in the cylinder. If the cylinder water is hot enough the the electric shower heater setting can be set to cold and you still get max pressure showering with the temprature of the water in the cylinder.

The trick here is to set your cylinder thermostat so that it will not to heat the water hot. Just luke warm.
(Remember the electric shower cannot cool water)

I have mine on a daily timer. Heats the cylinder water for 30 mins every 24 hours. This keeps the cylinder water luke warm.

Now I have full pressure from my electric shower even in very cold weather. And I'm using less power to run the electric shower.

There was a fella I came across who wanted 100% efficiency out of his living room gas fire so he ran a rubber hose into the middle of the room pushed a bit of copper in the end and propped it up on bricks, the other end he taped to a gas pipe, turned on the gas and lit it.

So I say to you what I said to him "yes I know it can be made to work but there are much safer ways of doing it".

Now admittedly he was unconscious and was on his way to hospital so I didn't get a reply:(

groodyman · 01-11-2015 12:18AM

I've been keeping the cylinder water just luke warm for years, don't need it really hot. Still no sign of legionaries disease.

The electric shower is no longer an annoying bare trickle in the cold weather.

So instead of installing an expensive mixer system with a seperate pump and using heaps of energy keeping the cylinder water very hot. I had just 10 minutes work swapping over a pipe and no cost at all.

Took a chance, it worked. I'm happy.

Dtp1979 · 01-11-2015 12:28AM

groodyman wrote: »

I've been keeping the cylinder water just luke warm for years, don't need it really hot. Still no sign of legionaries disease.

The electric shower is no longer an annoying bare trickle in the cold weather.

So instead of installing an expensive mixer system with a seperate pump and using heaps of energy keeping the cylinder water very hot. I had just 10 minutes work swapping over a pipe and no cost at all.

Took a chance, it worked. I'm happy.

Let's hope somebody you love doesn't die from your stupidity.

The Sidewards Man · 01-11-2015 12:31AM

Dtp1979 wrote: »

Let's hope somebody you love doesn't die from your stupidity.

Shot fired.

groodyman · 01-11-2015 12:35AM

It's all fun and games until someone loses an eye.

Or suffers death by lukewarm water.

The Sidewards Man · 01-11-2015 12:36AM

Them lukewarm molecules of water are ferocious for sure.

Dtp1979 · 01-11-2015 12:39AM

groodyman wrote: »

It's all fun and games until someone loses an eye.

Or suffers death by lukewarm water.

Or suffers death by water heated to less than 55 degrees, therefore potentially creating deadly bacteria to form which mostly leads to fatalities when the water vapour is inhaled, which is mostly from showers.

The Sidewards Man · 01-11-2015 12:40AM

Dtp1979 wrote: »

Or suffers death by water heated to less than 55 degrees, therefore potentially creating deadly bacteria to form which mostly leads to fatalities when the water vapour is inhaled, which is mostly from showers.

Have you links or some vague back up to this Halloween myth?

Dtp1979 · 01-11-2015 12:45AM

The Sidewards Man wrote: »

Have you links or some vague back up to this Halloween myth?

http://www.nejm.org/doi/pdf/10.1056/NEJM197712012972202
http://cmr.asm.org/content/15/3/506.short

Dtp1979 · 01-11-2015 12:47AM

http://cmr.asm.org/content/15/3/506.short

The Sidewards Man · 01-11-2015 12:47AM

That link is useless, I do not doubt that legionnaires disease exists, I want to know how many die in Ireland in showers from it.

The Sidewards Man · 01-11-2015 12:48AM

Second link equally useless.

01-11-2015 12:52AM

The Sidewards Man wrote: »

Have you links or some vague back up to this Halloween myth?

Why would you think it was made up?? is it just easier to think that those with experience Have been misinformed all there working lives.

mickdw · 01-11-2015 12:57AM

Is idiotic to scoff at this.
Good advice has been given and it is true that it is in showers that the biggest danger arises.
Anyway heating cylinder for 30 mins and storing a volume of water all day sounds inefficient compared to having the shower heat the water.

The Sidewards Man · 01-11-2015 12:57AM

Experience at what exactly, making up fairy tales of people dropping dead in the shower is it?

01-11-2015 01:00AM

The Sidewards Man wrote: »

That link is useless, I do not doubt that legionnaires disease exists, I want to know how many die in Ireland in showers from it.

There is a big debate in the UK at the moment (and I could see you being a great chairman) over the number of people dying from legionnaires vs those the number of people dying from scalding incidents, so because more people are at the moment being scalded some want to reduced the sitting temperature of stored hot water to lower temperature of 50c Ish.

Personally I'd heat the water to 60c then put a blending valve on the cylinder so nobody has to die, but what do I know.

Wearb · 01-11-2015 01:01AM

How many people die from electrocution every year. Not many. Because there are safeguards in place. Same with Legionares. People aren't dying with it because all good plumbing setups guard against it.

It's not common, but do you want a member if your family to be the exception.

The Sidewards Man · 01-11-2015 01:04AM

Gary how many in the Uk die every year form legionnaires? Bringing the scalding water is irrelevant and confusing.

01-11-2015 01:05AM

The Sidewards Man wrote: »

Experience at what exactly, making up fairy tales of people dropping dead in the shower is it?

I can act a a bit of a fairy at times but I don't tell tales.

I'm more than happy for you to shower in what ever temperture of water you wish as I do believe in natural selection, it's my job only to give you the information if you don't wish to except that then that ain't my problem.

Dtp1979 · 01-11-2015 01:23AM

The Sidewards Man wrote: »

Second link equally useless.

http://www.nhs.uk/conditions/Legionnaires-disease/Pages/Introduction.aspx

dazed+confused · 01-11-2015 01:31AM

The Sidewards Man wrote:

That link is useless, I do not doubt that legionnaires disease exists, I want to know how many die in Ireland in showers from it.

There has never been a recorded death from legionnaires disease that was contracted in a domestic building.

It has happened in hospitals, care homes, municipal buildings etc.

Dtp1979 · 01-11-2015 01:36AM

dazed+confused wrote: »

There has never been a recorded death from legionnaires disease that was contracted in a domestic building.

It has happened in hospitals, care homes, municipal buildings etc.

Link?

Can you plumb hot water supply into an electric shower ?

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