fireplace central heating with an extra electric water heater.

[Massiccio]

Hi I'm making up a Fireplace (underfloor + tabs) water heating, with additional electric boiler / under sink water heater which will serve as a cistern and as a water heater when the fireplace is off.  .. So I put 65m of 1/2'' pipe under the floor. Now i'll pass it through my fireplace via copper pipes. .. The water will come from the mains, go through the fireplace then go through the electric boiler (then connected to the taps) nd back to the fireplace . HELP PLEASE : Can I pass it through a 15 L. undersink, waterstorage heater 3kw, SO THAT IT WILL JUST GO THROUGH IT WHEN THE WATER IS ALREADY HOT FROM THE FIREPLACE and so THAT IT WILL START ND HEAT THE WATER WHEN THE FIRE IS OFF ???   THANK U ALL any comment will be appreciated.

 

[ProDave]

This sounds  a right bodge of a self designed system that has little thought for safety or regulations. I cannot think of one bit of it that is actually right.

I assume you are talking of a typical 3KW under sink hot water storage heater. They are not designed to work as a continuous flow water heater.

Get a proper heating engineer to design you an under floor heating system. You are wasting your time and potentially doing very dangerous things.

 

[Murdoch]

Apart from Dave has stated, if you choose to carry on without proper guidance and a design, you will end up with a bodge up that won't heat your house.......... then you will pay somebody to rip it out and do it again...

Your choice!

:facepalm:

 

[Rob_the_rich]

What will you do when the water turns to steam?

U/floor heating needs to be kept under 40-50degC.

What stops your water expanding into the mains drinking water?

 

[SPECIAL LOCATION]

Hi I'm making up a Fireplace (underfloor + tabs) water heating, with additional electric boiler / under sink water heater which will serve as a cistern and as a water heater when the fireplace is off.  .. So I put 65m of 1/2'' pipe under the floor. Now i'll pass it through my fireplace via copper pipes. .. The water will come from the mains, go through the fireplace then go through the electric boiler (then connected to the taps) nd back to the fireplace . HELP PLEASE : Can I pass it through a 15 L. undersink, waterstorage heater 3kw, SO THAT IT WILL JUST GO THROUGH IT WHEN THE WATER IS ALREADY HOT FROM THE FIREPLACE and so THAT IT WILL START ND HEAT THE WATER WHEN THE FIRE IS OFF ???   THANK U ALL any comment will be appreciated.

So I see two options here.....

1) either give us a proper detailed description of exactly how you intend this system to be connected....  (as what you describe is nowhere near enough to produce a safe working heating system).

or

2) stop what you are doing immediately and call in a qualified heating designer to provide a system that will work without endangering any occupants of the property...

Food for thought:-

Have a think about how old Steam Engines used to create enough power to pull whole trains full off passengers...

Heat from a fire and water in pipes can create immense amounts of energy.

If the wrong source of heat and an incorrect method of connecting pipes and expansion vessels is adopted then that energy can escape with catastrophic consequences!!!

:C :shakehead

 

[Massiccio]

Appreciated. The electric water heating will already have a pressure safety valve, and I will put an overheating release valve somewhere in there. The fire in the fireplace will always be contained and at a low heating value. And everytime the water will reach 30° a pump will make the water go around heating the floor then goin to the outlets while cooling itself down. ...   All I need to know is: will the 'under sink electric heater' let the water pass through it without problems. and without starting as long as the water will be hot enough ? ...  ... (.. steam engines .. interesting comparison) ... Many thanks! 

 

[Massiccio]

What will you do when the water turns to steam?

U/floor heating needs to be kept under 40-50degC.

What stops your water expanding into the mains drinking water?

Hi, Thank you! ..  naa it'll never get that hot to turn into steam. I'm gonna keep my fire to a minimum, If the water will reach 30° it'll be sent around the floor circuit, I'll feel hot nd I'll stop feeding the fire. .. The drinking water will be cold water which goes to the taps via a separated circuit. 

 

[ProDave]

Hi, Thank you! ..  naa it'll never get that hot to turn into steam. I'm gonna keep my fire to a minimum, If the water will reach 30° it'll be sent around the floor circuit, I'll feel hot nd I'll stop feeding the fire. .. The drinking water will be cold water which goes to the taps via a separated circuit. 

And when there's a power cut so the pump won't work to circulate the water? And you can't just instantly turn off a solid fuel fire.

There is a very good reason why solid fuel stoves used for heating water have to be designed carefully and to comply with lots of regulations so there is always a convection path for the hot water to flow away from the stove and somewhere for the hot water to go to dissipate excess heat. And then over heat and over pressure blow off systems to prevent the cylinder exploding.

Please do everyone a favour and abandon this ridiculous ill thought out scheme. Get a proper water heating stove and a proper designed system.

 

[Massiccio]

This sounds  a right bodge of a self designed system that has little thought for safety or regulations. I cannot think of one bit of it that is actually right.

I assume you are talking of a typical 3KW under sink hot water storage heater. They are not designed to work as a continuous flow water heater.

Get a proper heating engineer to design you an under floor heating system. You are wasting your time and potentially doing very dangerous things.

Hi, ye well if the electric heater will just allow the water to flow through it, it'll be switched off nd I will start it only when and if it'll be necessary  Thanks.

And when there's a power cut so the pump won't work to circulate the water? And you can't just instantly turn off a solid fuel fire.

There is a very good reason why solid fuel stoves used for heating water have to be designed carefully and to comply with lots of regulations so there is always a convection path for the hot water to flow away from the stove and somewhere for the hot water to go to dissipate excess heat. And then over heat and over pressure blow off systems to prevent the cylinder exploding.

Please do everyone a favour and abandon this ridiculous ill thought out scheme. Get a proper water heating stove and a proper designed system.

Thank you I'll keep this into consideration. There will be a overheating discharge valve in any case  

 

[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

 

[Massiccio]

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

Thank u, I'll try to get a contact to get proper infos. Thing is any constructor will never instruct me on using his 'creation' in a manner not ment for ...    In the main time I am getting loads of  very useful ''food for thoughts'' CHEERS

 

[Massiccio]

Hi I'm making up a Fireplace (underfloor + tabs) water heating, with additional electric boiler / under sink water heater which will serve as a cistern and as a water heater when the fireplace is off.  .. So I put 65m of 1/2'' pipe under the floor. Now i'll pass it through my fireplace via copper pipes. .. The water will come from the mains, go through the fireplace THEN THROUGH THE UNDERFLOOR and lastly through the electric boiler (then connected to the taps) nd back to the fireplace . HELP PLEASE : Can I pass it through a 15 L. undersink, waterstorage heater 3kw, SO THAT IT WILL JUST GO THROUGH IT WHEN THE WATER IS ALREADY HOT FROM THE FIREPLACE and so THAT IT WILL START ND HEAT THE WATER WHEN THE FIRE IS OFF ???   THANK U ALL any comment will be appreciated.

Sorry I had forgotten a piece :'(    

 

[binky]

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.

 

[Massiccio]

Hi I'm making up a Fireplace (underfloor + tabs) water heating, with additional electric boiler / under sink water heater which will serve as a cistern and as a water heater when the fireplace is off.  .. So I put 65m of 1/2'' pipe under the floor. Now i'll pass it through my fireplace via copper pipes. .. The water will come from the mains, go through the fireplace THEN THROUGH THE UNDERFLOOR and lastly through the electric boiler (then connected to the taps) nd back to the fireplace . HELP PLEASE : Can I pass it through a 15 L. undersink, waterstorage heater 3kw, SO THAT IT WILL JUST GO THROUGH IT WHEN THE WATER IS ALREADY HOT FROM THE FIREPLACE and so THAT IT WILL START ND HEAT THE WATER just for taps WHEN THE FIRE IS OFF ???   THANK U ALL any comment will be appreciated. (sorry my previous one was missing some notes)

 

[ProDave]

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.

 

[Murdoch]

^^^ wot he said!

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

 

[Tony S]

Hope the OP can swim.

 

[Doc Hudson]

Duplicate threads merged.

Doc H.

 

[phil d]

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.

 

[Massiccio]

Duplicate threads merged.

Doc H.

sorry, but the first time I placed it, i've omitted an important part, and I could not rectify. That's why I had to redo it. My apologies.