Christian McArdle wrote:
Can you suggest any cheap, but good systems?

Well the cheapest method is just to buy lots of PEX pipe and some clips.
However, there are lots of companies that will sort you out with kits. For
recommendations, you will need to say what your existing floor construction
is.

One issue is that underfloor heating must be run at a much lower temperature
than normal central heating or hot water heating. This means that you must
also install a thermostatic mixing valve and pump for the underfloor system
(this can be shared amongst all underfloor systems within the house). This
is easy to do and not expensive, but you need somewhere accessible nearby to
install the valve and pump.

Yup. Not recommened to run pipe-in-screed much over 45C whereas CH can
be up to 70C IIRC.

Simply restricting the flow ain't good enough - you just get high entry
and low exit temps.

You need an aux pump, thermo mixing valve and a relay, cos that pump
will be running (and need to run) independently of the main CH pump.

Christian.