IS anyone familiar with Primatic cylinders?

[allmodcon]

I am a new gas engineer (8years) and i havent come across one yet ,but is anyone familiar with Primatic Cylinders? How are they identified?
I have been told that if you need to work on the heating system and drain it down, than you will certainly have problems filling the system afterwards and bleeding the system due to the presence of an 'air bubble separating the hot water and heating water within the cylinder.
How on earth can this work? And how can you restore the air bubble when refilling the system

 

[sooey]

Just refill slowly, they're not usually a problem. The air bubble reforms by itself, don't add any chemicals though.

 

[kevplumb]

View media item 15179

How are they identified?

they have primatic or single feed stamped on them

dont see why it should be a problem filling and bleeding

the bubble forms itself (see pic )

 

[Andygasman2010]

Basically it'll sort itself out when you drain the refill it. Best ways to identify it are...

You'll only have one header tank in the loft instead of two

The flow connection on the side will have no bleed/fill/vent point on it, it'll go straight from the cylinder to under the floor.


If you ever take one out it might be an idea to cut it in half and have a look, it's hard to explain how the work. It's like an upside down bucket inside.

 

[penfold46]

Dont bung the cistern!

 

[jackpike]

you'll know when you drain the heating, it takes forever as its draing the water tank, cylinder and upstairs rads

 

[Biguns]

do not add chemicals or fit a pump

 

[kevplumb]

err they can be used on pumped systems

however ive never seen it

 

[transam]

err they can be used on pumped systems

however ive never seen it

I have some bloke down this way fitted a keston to a primatic cylinder ! seen several fitted to back boilers in mobile homes !
Always thought you could not pump a primatic , but you are now the 2nd person on here in the last few weeks who have said you can?? never new that !!

 

[roguetrader]

you can pump a primatic. another tell tail is the primary connections on a primatic are female threads rather than male.

 

[twgas]

I've never seen female primaries on a primatic.
I have seen one with a pump, it was connected to a circulator rather than a boiler and the pump, I believe, has to be on the return (that could be just my imagination).

 

[Andygasman2010]

A primatic can be pumped so long as the pump is on the return.

 

[5TIMES]

Can you turn it into a Cplan on these cylinders?

 

[Andygasman2010]

Can you turn it into a Cplan on these cylinders?

Nope! I originally thought you could until recently told other wise

 

[Biguns]

http://www.plumbingpages.com/featurepages/HWprimatic.cfm