primatic cylinder

[baggielad]

I want to eventually replace a primatic cylinder with a usual indirect one but is there any problem with putting in a separate f&e tank for the heating system before I get round to replacing the cylinder.

I'm in the process of replacing the old combined f&e tank at the moment and I thought that as I'm messing around in the attic I might as well plumb in a new f&e tank for the heating system.

Thanks for nay replies

 

[cross thread]

no carry on

 

[transam]

Are you intending to connect the new feed & exp tank to the system now ?
or at a later date ?? when you change the cylinder ?

 

[baggielad]

Are you intending to connect the new feed & exp tank to the system now ?
or at a later date ?? when you change the cylinder ?

Thanks for the replies. Yes I am planning to connect the tank up now as I assume that I can connect the feed/supply pipe from the new central heating f&e tank to the lower coil pipe from the cylinder (it's a gravity system)? Will it be ok to use 15mm pipe for the feed/supply pipe or should it be 22mm.

I can then simply move the expansion pipe for the heating system across to the new central heating f&e tank.

 

[seco services]

I can then simply move the expansion pipe for the heating system across to the new central heating f&e tank.

the old vent would of came of the top of the primatic useally your new vent
to the f/e will come of the primaries.

 

[transam]

So would that not mean that the central heating system is now fed from 2 different water source's exp tank & cold water tank ? primatic cylinder use's an air bubble to seperate heating & domestic water ??

 

[baggielad]

Thanks for the reply. Here is a picture of the cylinder and the old header tank

Untitled

• baggielad
• 2 Apr 2010
• 3

Untitled

• baggielad
• 2 Apr 2010
• 2

There is one vent pipe (22mm) which comes of the hot water pipe at the top of the cylinder and then another vent pipe (15mm) which is connected to the top coil pipe. It's the latter vent pipe which I assume is the one that should be moved to the new heating f&e tank?

 

[Nige F]

Put the F+E in and run the pipes near to exist. cyl . Leave it all dry A primatic has 1 feed and it`s from the domestic water . Do the final connections to the new cylinder

 

[transam]

I might be wrong? but from what I can see ? are you sure it is a primatic cylinder ??

 

[Nige F]

I might be wrong? but from what I can see ? are you sure it is a primatic cylinder ??

You`re right It`s a indirect with an annulus heat exchanger - and this has been here before I recall replying to it It`s a ballsed up setup - with the 2 vents over the 1 tank

 

[baggielad]

It appears that it is something odd, but there was a label attached to the cylinder specifically stating that only one tank was required, so this would indicate that it was installed correctly.

If it's not a primatic and it has been installed correctly and is not leaking should I just leave it as it is then. I am still replacing the tank in the attic as its the original, but if the cylinder is ok shall I just leave it?

 

[transam]

How many conections do you have to the tank in the loft
1) mains in via b.v
2) overflow 3) cold feed to cylinder 4) cold feed to cold tap's & ??

 

[baggielad]

How many conections do you have to the tank in the loft
1) mains in via b.v
2) overflow 3) cold feed to cylinder 4) cold feed to cold tap's & ??

I've taken the tank out and there was just the following:

1) mains into the tank (15mm)

2) overflow

3) cold feed from the tank to the bottom of the cylinder (22mm)

All the taps are connected to the mains.

Edit: so where is the supply to the boiler!? Is there some mechanism within the cylinder which transfers water into the heating circuit?

 

[transam]

In which case the cylinder must be a single feed primatic type , transfer of water takes place within the cylinder , the domestic water is seperated from the heating water via an air bubble only suitable foe gravity circulation inhibitors cannot be added as there is always the possibility that the water can mix ect the vent pipe coming off the flow is unusual & I have not seen that before than again one rarely see's a primatic cylinder !

I do not think that you can connect a feed & exp tank to the cylinder untill you change it as u would therefore be feeding the heating via 2 source's which could cause problem's !!If you google in primatic cylinder there is a site with various dia's that might give u a better understanding ??

 

[baggielad]

I do not think that you can connect a feed & exp tank to the cylinder untill you change it as u would therefore be feeding the heating via 2 source's which could cause problem's !!If you google in primatic cylinder there is a site with various dia's that might give u a better understanding ??

Many thanks for your help.

Just one further question. If I was to turn it into a fully pumped system I understand that the expansion pipe, the supply pipe and the pump have/should be close together. Therefore, would the easiest way to achieve this would be by adding an additional pump on either the flow or return pipe next to the cylinder as this is where the vent pipe is connected?