Old central heating to new

[cboswell]

Hi, I have an old open vented central heating system from around the 1960's
//media.diynot.com/192000_191914_49230_21769704_thumb.jpg
My system is the same as shown in the image.
I would like to replace my boiler and water tank but without to much pipe change. Is it ok to instal the new Pump and Mid pos valve downstairs above the new boiler and pipe these all into the existing pipework coming from my old boiler.
New boiler will be a glowworm HXI.
Thanks for your help
CLive

 

[45yearsagasman]

Your link does not appear correctly. Many boilers are installed that way. Is it remaining open vented or is your installer sealing the system?

 

[cboswell]

Thanks for your reply, i will be keeping an open vented system.
could you give me some clue as to how my pipe layout would be above the boiler to the new pump, valve and existing pipes.
I have 2 28mm for the hot water, and 2 22mm.

Many thanks for your help.
Let me know if the link is still a problem

existing system

• cboswell
• 16 Aug 2012
• 1

 

[cboswell]

This is what i was thinking of doing with the pipe work

Untitled

• cboswell
• 16 Aug 2012
• 1

 

[ALEC1]

just use a four pipe boiler with the valve inside....

 

[cboswell]

Yep i had thought about using a system boiler but i dont want to pressurize my heating system

 

[ChrisR]

CB - no you can't do that, you have to have a free path between boiler and open vent, which means moving some plumbing.
If you seal the system it does away with that requirement. TBH it's unlikely to blow apart. You can get an old rad valve leaking, or perhaps an old rusty rad, but those aren't hard to fix and need it anyway.

 

[cboswell]

Thanks for the replies, can anybody reccomend a good 4 pipe system boiler. I need around 24kw. I was looking at the GlowWorm boilers before.
Thanks

 

[ALEC1]

Viessman 100 and 200 fit the bill... With the 200 you have to use the cylinder sensor IIRC, and the system must be sealed...

 

[dcawkwell]

Open vented systems have no place in a modern heating system