Parkray Chiltern and my central heating system/ hot water

[awja]

Can anyone help me with the following:-
I have a Parkray Chiltern and an unknown make of tank.
As far as I can see the system is set up as illustrated below.

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• awja
• 12 Aug 2008
• 1

I am curious to know how the heating water is kept seperate from the hot water to the taps.

 

[spacethegas]

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• spacethegas
• 12 Aug 2008
• 1

 

[awja]

That's what I thought but how does the whole system (Central heating & fire back boiler) get filled with water from just filling the tank ?
There must be some physical connection between the two parts.

 

[spacethegas]

generally there are 2 tanks in the attic.
the large one feeds the h/w. the small one feeds the boiler & heating.
alternatively you may have whats called a primatic cylinder.

 

[awja]

spacethegas
Thankyou for that.
It must be a primatic tank as I have just had a look at how they work and they fit the description to a tee.
I now know basically how they work now but if you know of any web sites that give an in depth description/diagrams it would be appreciated as this is the only diagram I can find and it isn't very good.

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• awja
• 12 Aug 2008
• 1

 

[spacethegas]

all the detail you need to know is in the diagram.

the only thing that separates the dhw & heating is an air bubble.

its not generally considered to be a good idea nowadays.

you cannot introduce any chemicals to protect the heating system as there is no physical barrier between the two systems & there is always the possibility of loosing the air bubble with the consequence of contaminated dhw.

also if an airlock were to develop within the heating system you will not have the option of backfilling the system.

 

[tomm174]

spacethegas
Thankyou for that.
It must be a primatic tank as I have just had a look at how they work and they fit the description to a tee.
I now know basically how they work now but if you know of any web sites that give an in depth description/diagrams it would be appreciated as this is the only diagram I can find and it isn't very good.

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• awja
• 12 Aug 2008
• 1

Here's something
http://www.go-repairs.co.uk/#/cylinder-types-continued/4535075835

 

[Terrywookfit]

It should not be fitted on a Primatic system.
Installation instructions state that it should be a "Double feed indirect".
A heat leak rad is also needed.