Upgrading one pipe to two pipe system ready for new Boiler

[Blaze]

Hi,

Looking at upgrading from a one pipe radiator system to a two pipe radiator system and wish to know if I can do this on the existing system.

1963 house, floor standing Ideal Mexico Boiler (works well), DHW Cylinder in airing cupboard, gravity feed system with f&e and cold water storage in loft.

10 radiators in house at present, will go to 13 in around 1 year. Current rads based on BTU measurements come to around 49,000.

Would like to upgrade central heating pipes from copper to plastic (using hep2o). Looking at running 22mm feeds with 15mm spurs for radiators.

Also looking at replacing radiators with new, placing TRV on all apart from hallway where new control will go when upgrading boiler.

Question
Already started building up a schematic of which pipes currently go where and was wondering if central heating rads can be isolated from system by placing some form of connectors / connection (loop back?) at the beginning of the central heating pipe run.

This would hopefully allow us to continue using Boiler to heat DHW Cylinder but would it be an issue to not allow the heat to flow around the rads ? (Other than heat the house of course.)

The reason why I would like to turn the rads off is that I would like to run the hep2o under floorboards and down walls (would channel the wall and place piping in conduit to allow for maintenance). I see that this would be at least 2 weekends of work for me to complete the task.

Can this be isolated ?

 

[bab]

As long as the feed & vent remain on the system & if this is gravity hot water then they should be on the cylinder so it should be fine. with a one pipe system if u break the ring then all the rads on the ring stop working thats the worse case. But at this time of year its a case thats not ideal.

 

[Blaze]

Cheers Bab,

f&e on the cylinder (albeit its upside down as in hot at bottom, cold at top) and would still look to keep this on the go.

Once I've found the feed(s) off from the Boiler pipes to the airing cupboard what is the best way of shutting off central heating ? for a couple of weeks.

 

[ChrisR]

A pair of full flow ball valves, and a drain cock. Use GOOD ones (Peglers, Conex, Plumbcenter own brand are OK) and you can leave them there for future use.

 

[ricarbo]

Why not fit an electric immersion heater to the cylinder? It would take the pressure off you while you're working on the heating pipework. And you'd have a backup sytem for the water, in future.

 

[Blaze]

8) Anyone seen my glasses ? ..... Oh, they are on my face

Thanks Ricarbo,

An Immersion heater is already fitted to the cylinder so I could use this to heat water as and when needed (has a timer on it as well).

Cheer ChrisR - I presume these would be fitted where ever I find the pipes to and from the Boiler break out to the Central Heating.