How to replace microbore radiators

Posted 17th Sep 2023

I've got a few of these and am thinking about the process for replacing them because they are fairly old, potentially ahead of a heat pump installation. The in and out pipes are on the same side.
Any hints/tips are most welcomed.

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17th Sep
What is on the other end of the radiator?
Author
17th Sep
Nothing. All the connections are on this side.
17th Sep
If you want to replace the valve to a 15mm valve of the same type you need to buy a twin entry radiator valve for starters.per radiator @ £100 plus per radiator.
https://www.screw***fix.com/p/t…9hr
Then you would have to locate the manifold where the 15/22mm central heating pipe from your boiler splits into the microbore. They look like this & it should be under the floorboards on the first floor.
That would need to be replaced to take 15mm pipework. Which you would have to pressure test because if you don't get it right then you can say goodbye to your ceiling.

Then you would have to feed all that 15mm pipe around the house by ripping up all the upstairs floorboards, drilling holes in the joists as you go.

Then you would need to feed those 15mm pipes down the sides of your downstairs walls or chase channels in your walls & plaster over & repaint the walls.

Or, just leave it as it is. It would be a very expensive, time consuming job & not really for anyone but a pro to attempt. (edited)
Author
17th Sep
I am pretty much stuck with them in that case. Won't be an easy job either to replace the pipes or the radiator. I may have to think outside the box. Seems that heatpump is out of question with these.
17th Sep
That will be about 30 years old, maybe more. It is just a normal radiator and there will be a long tube from the valve to the other end of the radiator.

Amazed if it still works after all these years.

You could use that radiator with a heat pump (but don't) but it is the microbore pipework that will need replacing throughout the house - not just the bit that sticks out of the wall !

New pipework throughout the house, new radiators and a lot of room for all the storage tanks and exchanger tanks. Fun......
Author
17th Sep
It works. For how long? I have no clue. I dread to think about the bill when I have to change that. It's as if the companies that designed the system had planned obsolescence in mind. Somehow...
18th Sep
You might want to look into water based underfloor heating if it is suitable for the house, no doubt it is more expensive, but I believe it is supposed to work better than rads for the lower temperature water from a heat pump system.
18th Sep
My folks have this set up in their apartment. I only discovered how it worked recently.

Microbore is a big no no for Heatpumps and if the house is from the 80s, I would suspect that that is the least of the worries heat pump wise as you will be lacking a lot of the insulation and draught proofing required for one unless this work has already been undertaken?
I have a 2012 house with UFH downstairs and this only just scrapes through as passable despite everything being insulated.
4 m ago
I have as 2004 house with plastic MB, heat pump fitted 4 weeks ago. - no issue at all.

the flow was totally fine, has increased to P3 some rad but again flow was sound.

British Gas as part of ASHP run NEW rads and pipes to all rooms as the "gurantee" heating to all rooms. Octopus left it and that's what I wanted. - brilliant install and I love the ASHP.
any Q pls pm me.