Heaters not working

apmac

Hi, hope some of you can help...

We moved in around a year ago to a 70s built 4 bed detached house. It originally had storage heaters but at some point has had central heating installed.
During last winter/spring, a few of our downstairs radiators gradually stopped working. Initially it was our big hall radiator which is just stone cold all over (despite being switched on!) and now our 2 living room radiators are starting to go cold, at the bottom so not needing bled.
We are planning on having other work done including laying a new laminate floor throughout a lot of the ground floor and relocating the boiler to the garage so this is the ideal time to sort it. A couple of plumbers were round in the summer to quote for the whole job and the first guy looked at the radiator and straight away said he could flush it (like I asked, as that's what I thought would sort it) but that our system was microbore and it was likely that any blockages would be due to the skinny pipes and would recur. He suggested replacing all the pipework to the downstairs radiators with bigger pipes before we lay the floor. He also said that it would be just as cost effective as flushing the system.
I was persuaded and he seemed to know what he was talking about but my husband has had a wee look into microbore and it sounds like it's used for a reason as it can be more cost effective to run(?) so thinking we could be doing with some more opinions/advice...
Any thoughts would be really appreciated! Thanks!

phill99

Microbore is often used for new builds as it is easier to install, needing fewer joints, elbows etc. However the house builders aren't the ones that maintain it in the longer term.

In hard water areas it scales up quickly. You also need to ensure the system has adequate cleaning agents / inhibitors installed. Regular servicing is also important.

I would go along with what your plumber advises and change it all to 15mm.

apmac

Ok thanks for that. I guess it's important we get this right before the floor goes down! If it has any bearing we are in Scotland and don't have any problems with limescale...

phill99

Limescale or not, microbore isn't very forgiving. Sludge will soon block it up.

When was it last serviced or had inhibitor added?

bridgedino

Worth getting a magnetic filter fitted on your system if you can as well. I've seen some real thick black sludge build-ups collected in these over the course of a year.