Changing a Primatic cylinder to an indirect system

[Lazwal]

I have a gravity fed hot water system with a pumped central heating system. In my loft I have a Feed and Expansion tank with a hot water cylinder. My central heating boiler is in the kitchen with the pump directly above it. Due to the immersion heater and the position of the cylinder right next to the roof beam i could not access the immersion fully so I decided that I would fit a new cylinder and re position it so in future any problems with the immersion would not exist. I purchased a new indirect cylinder as i thought that my old one was the same, first mistake, I drain all the hot water and central heating systems and fitted nice new cylinder in new position and filled up heating system switched on immersion,lovely hot water,great I thought, ah but what about the central heating, it was not filling up. The wise members among you will already know what I am going to say,fitted wrong cylinder should have replaced it with a primatic cylinder. When I looked inside the old cylinder that is what it was. So now I need to address the problem of how to supply my central heating system. I have been advised that I can fit a second F.E tank with a feed and vent pipe to my new cylinder My boiler has two 28mm pipes for feed and return and the pump has a 22mm pipe. With the 22mm pipe it would have gone back to the hot water feed in the loft. I would be grateful of any advice.

 

[jtsplumbing]

Why not just upgrade to a fully pumpd system, you will need a small tank in loft , you will have to tee off the gravity flow and return pipes from cylinder 22mm open vent to go over the top of ex tank (Off flow pipe) 15mm cold feed into return, Try to get small tank as high as poss at least above the main water tank. This is a very basic system that you have and easey to adapt.
I am sure that you will get plenty of advise on here.

 

[DirksPlumbing]

Why not just upgrade to a fully pumpd system, you will need a small tank in loft , ...

The basics would indeed be the mentioned tank only and fill and expansion.
But a fully pumped system would offer you the possibility to an interlocked system. Which means your boiler will only run when it is required and only heat the required parts of the system. If you recon that your boiler will last you for a while then this could cut your gas bill down a bit.
If you are eying up a combi at some point then just go for the small header tank + feed/expansion.
Otherwise a fully pumped system would offer you the possibility to change your boiler with little interuption at any point you want.
Condensing boilers must be run of a fully pumped system anyway.

 

[SimonG]

You will probably find that the new cylinder has a label on it saying that it is only suitable for pumped primaries. Your halfway there now so might as well change to fully pumped system as said above.

 

[Blumper]

..Or you could just pay an experienced fully qualified plumber with all the tools and know how to sort it for you, that is, after all, why most of us have a few thousand pounds worth of tools, in a van that's expensive to run, with public liabilty insurance which don't come cheap and countless other debts brought about through training, advertising, doing free quotes etc etc etc etc.

 

[Lazwal]

Thank you all for your kind replies and sound advice, when submitting my post I wondered when I would get the Blumper reply! most useful no wonder that many having undertaken tasks and come to grief are unlikely to bite the bullet and post. Maybe next time I will not bother. But again may I thank the other members who took the time to assist me.

 

[diamondgas]

:welcome: to the forum Lazwal

Sounds like you have an old system. Some sound advice above regards converting to fully pumped, & the possibility that your cylinder may not designed for gravity! However the cheapest route would be to install a separate header tank for the heating incorporating a cold feed and open vent design. You can research that quite easily! Main thing to remember is DO NOT under any circumstances fit any isolating valves to either the feed and/or vent pipe!

If it doesn't work on gravity then you can always get the experts in to price for a conversion for you IMHO

 

[Lazwal]

Thanks good advice appreciated.