In an earlier contribution to this discussion,
Simon Hawthorne wrote:

Hi all

Just finished the job I started last week - fitting a TRV to one of my
radiators on my microbore system. Actually removed the rad yesterday,
flushed it out with a hosepipe- then cleaned the threads for the
valves with a toothbrush - used '5 turns' of tape on the valve threads
- and reconnected. Dry as a bone now!

Anyway, I would like to add another rad to the downstairs circuit. As
far as I can see, the circuit of fed on a 22mm pipe from the boiler to
a manifold - where lots of 8mm pipe branches off the the rads. The
retur pipes are the same. To add another rad, can I simply but an
equal T joint into one of the micorbore feeds, and the same on the
return? If I do it on the feed to the closest existing radiator, will
it work?

I understand that there would be a temperature drop in the existing
rad, but that is the one I have fitted a TRV to - because the room
gets very warm - so shouldn't be a problem. I only want to run about
4m of pipe from it - and put on a small new rad in a corner of the
kitchen that is about 18 feet from the nearest other rad - and gets
quite cool...

Thanks in advance

Simon

There are rules of thumb (which I'm sure others will quote) about how much
heating capacity you can get from an 8mm pipe. If it's less than the
combined output of your two radiators, then you shouldn't be doing it. I've
never used microbore, but my understanding is that it's usual to have
individual feeds for each radiator from the manifolds. Have you got any
spare tappings on the manifolds? The other alternative is to tap into the
22mm flow and return pipes using 22x22x8 tees.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.