fireplace central heating with an extra electric water heater.

[Massiccio]

THIS IS NOT !

A) Going to work!

B) Be safe!

C) Comply with the relevant safety regs!

D) End at all well!

A heating circuit is just that, a circuit, it needs a flow and a return, plus temperature stats, overheat stats and pressure relief devices.

You cannot take cold water from a main, send it into a load of pipework, heat it up and expect it to heat a room, then connect the other end to a tap.

Think about this, when you turn on a hot tap, you don't get hot water instantly, there is always an amount of cold water comes first, dependent on how far the tap is from the heat source, this is known as the "dead leg". Connecting the way you propose you'll have a massive "dead leg", then you'll probably get about a gallon of luke warm water before it goes cold again. The room will not be heated either, the only thing you may do successfully is create a breeding ground for the Legionella bacteria, and let me tell you, if you are responsible for an outbreak of Legionnaires disease then may god help you because it's jail time!

As everyone else has said, you are woefully out of your depth here, for the sake of your family, get a professional in.

Thanks but U are too dramatic. The worst it'll happen is to have cold water nd a warm room. I'm obviously gonna put safety pressure and temperature gauges nd discharge valves. It'll b nice if someone would just advise me on those  .. 

 

[Massiccio]

And how does this differ from the same question last week when you were advised to get a professional to design it properly?

So mains water in, through the fireplace, theough the under floor heating, through an electric heater then out of a tap.

So what happens when the tap is turned off? No water flows.

Please abandon this stupid idea.

.. when the taps are open the water branches off that way if they are shut, the water keeps circulating back in the circuit!  Imagine a closed circuit of pipe which passes through a fireplace and through an electric water heater. The water just circulate passing through them. ...  The only differences are:  -at a certain point (on the return) there will be an open main (which water will push in only when there will be a drop in pressure)  - at another point, past the hating devices, there will be a tap. (when the tap opens the pressure drops and water from the mains will flow in). There will also be a pump which will ensure the circulation when the circuit won't be pushed by the mains flowing in. I think with the right safety gauges it can work  .   Thank you.

 

[Massiccio]

^^^ wot he said!

Not sure the OP is taking in what we say as he's already laid the underfloor heating pipes!

I'm tryin, but as someone said i'm a 'stone-head' .. it'll take some time for ur lovely comments to be considered Thanks 

 

[Massiccio]

sounds like you want a good old fashioned 'back boiler' . My parents still have one of these behind their coal fire. Trouble is you will find it very hard to find a plumber who understands this old tech. It's a simple enough system, heat exchanger behind fire linked to hot water tank in airing cupboard. From tank hot water is supplied to house taps and radiators.

With regards to electric hot water heater, if the tank is hot, I don't think it will try to heat water, but these tend to be set for around 50 Celcius to avoid legionella issues as far as I'm aware. They also tend to have cycles to heat to higher temps to kill legionella. I think your best option is to contact Tech enquries for the tank manufacturer, and see what they say.

Finally someone who can give constructive advice instead of no-can-do jaba jaba LOL. Thanks man. One love!

 

[ProDave]

.. when the taps are open the water branches off that way if they are shut, the water keeps circulating back in the circuit!  Imagine a closed circuit of pipe which passes through a fireplace and through an electric water heater. The water just circulate passing through them. ...  The only differences are:  -at a certain point (on the return) there will be an open main (which water will push in only when there will be a drop in pressure)  - at another point, past the hating devices, there will be a tap. (when the tap opens the pressure drops and water from the mains will flow in). There will also be a pump which will ensure the circulation when the circuit won't be pushed by the mains flowing in. I think with the right safety gauges it can work  .   Thank you.

So what will circulate the water until you decide to turn the tap on?

Mains water into a circulating heating loop then out of a tap. I cannot begin to tell you how many rules and water bylaws you are proposing to break. And yes Legionaires is a REAL risk with what you propose.

This thread should be deleted, because this reputable forum cannot play any part in helping you do something so blatantly dangerous in so many ways

 

[Rob_the_rich]

Where do you live Massiccio?

 

[binky]

So what will circulate the water until you decide to turn the tap on?

back boilers utilise  a good old fashioned pump to circulate water around system. They don't separate hot water for taps from radiators, or at least my parents doesn't, hence the old fashioned advice of not drinking water from the hot tap. 

 

[Doc Hudson]

And what do the manufactures instructions for the device you intend connecting up say about your proposed configuration?  I can't quite work out which is the more dangerous, your rather sketchy proposed design? Or asking random strangers on the internet if a device that you provide no model or make or manufacture description of will work in what is a daft design arrangement. I would suggest you ring the manufactures or, just connect it up how you want and see what happens.  As I cannot see how anyone else on here could offer any more practical advice other than get a professional heating design engineer to look over your proposals.

Doc H

So, I shall repeat my earlier question of 3 Oct, after which 4 Oct you said you would be contacting the manufacture of this, (as yet unidentified), water heater.  Please can you understand that for people to offer you practical and useful answers to your questions, often they will ask questions back to you, to get greater detail so as to offer an appropriate answer. Without more factual detail about exactly how this proposed system is going to be connected up, (e.g. drawing/.plan/sketch of the system), our members are guessing. You may as well ask any random vague question you like to a complete stranger at a bus stop and expect them to be able to connect your system up. Based upon the vagueness of your question I fail to see how you can interpret any of the very constructive answers given so far as "no can do Jaba Jaba"?

Re the 15l 3kw under sink water heater:- 

1) What is the Make of this proposed water heater?

2) What is the model number of this proposed water heater?

3) What do the manufactures installation instructions say?

4) What was the response for the inquires you said you were going to make?  (Or didn't you contact the manufacture?)

Please answer each of the above points, otherwise I would have to assume this is just a 'wind-up' thread with no possible genuine answer actually needed.

 

[Lurch]

back boilers utilise  a good old fashioned pump to circulate water around system. They don't separate hot water for taps from radiators, or at least my parents doesn't, hence the old fashioned advice of not drinking water from the hot tap. 

I think you've got a few systems mixed up there. Having a back boiler doesn't mean you can't drink water from taps.

 

[SLIPSHOD & SLAPDASH]

Even if this did work, i donr know any undersink type 3kw water heater that  passes water though, they are stored water.

The only thing similar to what you want is a standard hot water cylinder fitted with a 3kw immersion but even the smallest wont fit under a  sink and i doubt the heater could keep up with the flow, its designed to heat the water static in the cylinder.

 

[ProDave]

Willis heater?

 

[Doc Hudson]

https://www.tlc-direct.co.uk/Main_Index/Domestic_Index/Instantaneous_Water_Heaters/index.html#Rho_Instantaneous

Any quick Google will bring up a varied selection of possible instantaneous water heaters, an example of some is above. Plus you can view the installation instructions on line.  However the smaller power items are typically for a single tap application, whereas I get the impression you are looking to feed all the hot taps in the property?  What is the 'heater' you are considering? I presume you have searched optional products before starting a project such as this. 

Doc H.

 

[Tony S]

I think you've got a few systems mixed up there. Having a back boiler doesn't mean you can't drink water from taps.

If you’ve seen the amount of shyte that builds up in a convection back boiler you wouldn’t want to drink the hot water.

 

[Lurch]

If you’ve seen the amount of shyte that builds up in a convection back boiler you wouldn’t want to drink the hot water.

I never said you would, that is why you generally have a hot water tank with an indirect coil.

 

[Tony S]

I never said you would, that is why you generally have a hot water tank with an indirect coil.

Convection back boilers used a direct hot water cylinder, the water going through the boiler was the same water coming out of the tap.

 

[Lurch]

Convection back boilers used a direct hot water cylinder

Some did.

 

[binky]

my parents does, I'm fairly sure. The old don't drink from the hot water tap is supposed to be due metallic contamination from lead pipes, but then my parents also fill the kettle from the cold tap last thing at night to avoid the same thing. There's not an inch of lead in their house  :slap

 

[Blue Duck]

I thought it was incase there was a drowned rat in the header tank?

Knew an establishment where the staff were showering in rotting rat carcass' for months...

:lol:

 

[Lurch]

The old don't drink from the hot water tap is supposed to be due metallic contamination from lead pipes,

Does lead contamination only occur in hot pipes? I think the 'don't drink from the hot tap' thing is because of the stored water.

Knew an establishment where the staff were showering in rotting rat carcass' for months...

Fairly common on commercial properties. Was very rare to remove a header tank from a school or small office block and not find pigeons and rats in them.

 

[Doc Hudson]

Well I assume at some point this link will have to be added, so I think I will do it now.





Doc H.