mikeguitar

Yup, are you satisfied that the rads are properly balanced? Check the uk.d-i-y FAQs website - there are from memory a couple of articles about rad balancing, invest in an IR thermometer, and check them out. You could save yourself a great deal of time, effort and money, and impress 'Er Indoors with your frugality......

cheers wanderer Ill investigate, nothing does it for er indoors th

-- mike guitar

A good question! If you use a larger pipe there will be more surface area in contact with the absorbing ground/screed. Depending on how/where the piping is installed you may be able to use some of the heat dispersed into the substrate.

cheers Frank , actually I was considering putting the pipes on th surface of the rooms behind cupbards etc, I can divert pipes behin kitchen cupboards, thru walls et

-- mike guitar

One poster has suggested balancing ... good idea, I wrote a large article for the FAQ many years ago ... not sure if it is still used. Make sure you take car of setting correct pump speed as well.

If it were me I would heat up system, drain it refill with a desludger/system flush additive (any plumbers merchants) run it till hot drain, flush again. Then add fernox ... and fill, bleed fully then carry out the balancing.

Rick