Can you put Expansion vessel in the same location as previous open ventd header tank

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Can you put Expansion vessel in the same location as previous open ventd header tank

Discuss Can you put Expansion vessel in the same location as previous open ventd header tank in the Plumbing Jobs | The Job-board area at PlumbersForums.net

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interesting100

I have a header tank at ceiling height on the first floor and we want to put rads on the 2nd floor above the header. - It would be v. difficult to raise the header tank

Is there any reason why you can't put an expansion vessel in the same place as the existing header tank, so it replaces the header tank ? It seems a simpler / more logical way of doing it

( I know normally you fit it at boiler level on the return pipe, but there are difficulties with that here, whereas it would be easy at the header tank location )
Thanks
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

If you remove the tank feeding the heating the system will then have to be a pressurised system, as long as your system looks like it can cope.
get someone to have a look and give you a quote for the work.
 
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Can you put Expansion vessel in the same location as previous open ventd header

Its doesn't matter where it goes on the system, just bare in mind where your blow off is going to terminate
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

There is more to pressurizing a system than just putting in an expansion vessel.

The manufacturers installation instructions must be consulted as some boilers cannot be pressurized.

Also there is safety discharge and filling to be considered.
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

Thanks Heliotrope -good points, (its a new WorcesterBosch 24Ri )
but that is in many ways the whole point -
At the header tank site, you already have a mains cold feed for filling and a waste pipe for the safety valve discharge, so is it not preferable to use them rather than put new ones in by the boiler ?
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

As longs your not thinking of re-using the tank overflow as your safety relief pipework!
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

When a prv lifts at 3bar it is almost always when the system water is hot. Boyles Law can also come into play which means the hot water can flash off into steam. For that reason discharge pipework must be metallic. Not plastic.
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

aslong as you divert the outside pipework to a safe location, as most overflow/warning pipes are positioned to be a nuisance. ie over a window or doorway.
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

croppie said:
When a prv lifts at 3bar it is almost always when the system water is hot. Boyles Law can also come into play which means the hot water can flash off into steam. For that reason discharge pipework must be metallic. Not plastic.
Click to expand...
funny you say that, Veissman vitodens 100 have a combined prv discharge and condensate plastic tube. Here what they stated: Espected question from installers because of the believe that if the SV opens it releases boiling water or steam into the pipe work.This is not entirely correct. It is a pressure relief, therefore unlike with un-vented cylinder it only opens if the pressure of the boiler increases beyond 2.5 bars. The opening is gradual which means only little water discharge occurs. The valve closes as soon the pressure drops below the threshold. This from Viessman technical.
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

Veissmann have designed their safety valves and their systems. We're talking about a different safety valve designed to lift at 3bar, and not graduated either.
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

fm memory Boiler needs to have overheat stat that isnt self resetting amongst other minor reqirments. you dont mention wether your using gas oil or solid fuel for the boiler either, definite no no for wood or coal burners
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

It's a Worcester 24Ri so boiler complies with requirements. Just a case of doing the rest correctly.
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

Blow off pipework must have a fall with no horizontal sections
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

WHPES said:
Blow off pipework must have a fall with no horizontal sections
Click to expand...

so what do you do when you fit a boiler not directly on an external wall where it cant just go straight down and out the wall?
 
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Re: Can you put Expansion vessel in the same location as previous open ventd header t

best practice is to fit vessel under pump as you would a feed and exp
 
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