Variable flow Water Pump for instant water heater?

[DuckyUC]

Hi again

I fitted a instant electric water heater to supply hot water for whole flat
but the hot water flow are quite low

So I am finding a pump that can:

1. pump only on when water flow
so no pump noise all the time and the pump have longer live

2. pump can tune how much water flow/pressure to increase
the water heater have a max 10bar Rated pressure
If the water flow too high the water heater wont able to heat up the water to require temperature

I find a pump call Salamander home boost on google
It only on when water flow but it design to maintain 12L/min all the time so I do worry that will give too high water flow and the water heater wont able to heat up the water to require temperature.

Any recommend for water pumps?

 

[Killy Bing]

Lets say it cost more money than you would want to part with !!!

the basic jist is that if you want an unlimited/high amount of hot water at a good flow rate in any installation you require quite a good design element and you only get that from someone with the training and experiance.

also there is a cost. the better the system you want the more you have to pay out.

It's impossible for you to get what you desire unless you part with quite a substancial amount of money.

Also the current set up you wish to use will not work

if you can only use electric then a pulsa coil style combi heater would be your best bet

http://www.gledhill.net/pdf/Spec%20101-02%20PulsaCoil%20BP.pdf

The other options are undersink water heaters and an ellectric shower.......

 

[Dotty]

Even my current shower give 4.8L/min, you have 2hours shower so that will be at least 2 X 4.8L/min X 60min = 576L
120min+20min to heat the water, 576L/140min = 4.11L/min

How many Amp does your boiler use?

You really, really should have paid attention to the advice you were given.

Because you didn't you've now got an expensive white elephant.

Oh, and for the record, my indirect unvented has a recovery time of 20 minutes too. The boiler's on a 5a spur.

But then I know what I'm doing and, when I don't, I pay attention to any and all advice given.

Especially when I'm told I need to get someone in.

You live and you learn eh?

 

[Billy Bob Bob]

me not understand why me head hurt:banghead::banghead::banghead::banghead::banghead::banghead::banghead::banghead: you must be class a plonker

 

[lame plumber]

in future when a poster like you appears, I'm going to take up my kids old mantra that they used when they got fed up with being told what to do. " LA LA LA LA LA LA LA LA LA LA"

 

[Howsie]

I'm out out out. I'm disappointed with myself for even posting again on this thread because in know it will pop up on my learned friends new posts search.


Sorry chaps.

 

[DuckyUC]

I already get the system installed, and it work. It gives enough hot water. I only want to install a hot water pump to improve it, that simple. Why you guys seem anyone not using an unvent system are wrong? Instant hot water are so common in other country, whats the point of get an massive water tank that require more maintenance and more risk of leaking?

At the end of the post the ppl seem even made up an unvent system that only exist in imagination.
Hot water last for 2 hours and take 20min to recharge with amazing flow? If you can give me such a amazing model to me I will unstall my current system and install that unvent model.

Let say you have a 200L tank with all hot water heated up in E7 period, shower take 5L/min
200/5=40min shower

If each shower take 20min, that will be enough hot water for 2 shower.
For the 3rd person need a shower, he will need to wait the whole water tank boil to decent temp.

How long do he need to wait?
A immersion normally have 3kW output, 3000W/230V=13A (normally have 16A breaker in the fuse box)
My 12KW system can heat up 5L per min instantly
3/12=1/4, 5/4=1.25L per min
So 3kw should able to heat up 1.25L per min
200/1.25=160min=2hours40min.
With an immersion for the 3[SUP]rd[/SUP] person shower need to wait 20min (1[SUP]st[/SUP] and 2[SUP]nd[/SUP] shower run at same time)+2hour40min =3hours


With an instant heater the 3[SUP]rd[/SUP] person shower need to wait 20min(1[SUP]st[/SUP] shower) +20min (2[SUP]nd[/SUP] shower)=40mins


How come the unvert immersion becomes better?
Even with a 9kW output will still take 53min to heat the full tank of water
=53+20=1hour 13min waiting time

I would bet the fact is you take a 20min shower which use up half of the hot water, and the 20min recharge just heat up a bit the remain hot+ cold water mixture.
The point is if you do believe unvent system is the ultimate solution then give a physically exist model with spec rather keep saying how crap other system is.

 

[DuckyUC]

And my boiler room not even have space to put a 200L tank, I guess even I get an unvent only can have 150L max. Do you guys understand why I rather prefer get instant system at the cost of only 1 shower can run each time now?

 

[lame plumber]

la la la la la la lal la

 

[happyflyer]

Have you thought about this guys, this could be an old plumber playing mind games with use, dats what I fink, it's a wind up and you have all fallin into the trap, BTW did I reply to this post, my memory is going now, this chap needs a left handed fluffle valve, that will fixed or someone needs to block the thread with a Yorkshire 61.

 

[Howsie]

A shower does not use only hot water. As soon as the cylinder stat calls for heat the water is being heated. The recovery times mentioned are for a complete reheat not a top up.

Your understanding of the subject is poor that is why you are clinging onto a 5l shower rather than listening to the good advice from people who do this everyday.

Are you an engineer by chance?

 

[PlumbBobBob]

it is all getting very monotonous now imho

 

[lame plumber]

la diddly la la (change of tempo to improve the thread )

 

[Dotty]

la diddly la la (change of tempo to improve the thread )

Pom pom!

 

[DuckyUC]

my current system give 5L hot water @ 55C,
if the unvent system can mix cold water to increase the flow, so do I.
If the unvent give event less than 5L per min whats the point of geting an unvent?

 

[DuckyUC]

too many unvent fundamentalist!

 

[Dotty]

Could always fit an inline heater and pump on the shower hose.

Clever things.

Look for all the world like fan heaters.

Try taking a fan heater into the shower with you.

 

[DuckyUC]

No, Kettle is better.

 

[DuckyUC]

Low cost(£30), cheap to install (£0), high out put (3kW)(same power as an immersion)

Anything better than the kettle?

 

[DuckyUC]

croppie:

If your water heater only draw 5A that mean it is using gas to boil the water,
the 5A pretty sure is not for the heating element
the 5A only for the control board+pump etc

and I dont even have gas in my flat so it is not a option

 

[Howsie]

You can keep your dribbly 5l per minute and I'll stick with my 20l.

I'm out. For good this time.

 

[DuckyUC]

how long your 20L per min last?
200L/20L=10min

That is a quick shower.

 

[DuckyUC]

So professional advise is get a system that last 10min and take 3hours to recharge.

Well...

 

[DuckyUC]

I bet those unvent fundamentalist have converted half of their house into boiler room if they have a big family.

Have a series of water tanks sit in the living room(converted into boiler room) in order to store their hot water.

Otherwise they all live in 1bed property with them self so never need to worry about running out of hot water.

 

[Killy Bing]

The plusa coil link i have you acts as a combi, heats up the store of water and then runs mains through the coil to bring it up to temp.
it doesnt deplete the store with each use but gradually depletes the temp.

bigger the store the more instant hot water the coil can provide.

 

[DuckyUC]

1king55:

Yes the boiler I have before is plusa coil do work like you said. It heat up the still water in tank(unchange) and the fresh water run through the hot still water.

That design provide higher pressure but what pull me off is the low output of the heating element (3kW)