On Sat, 20 Jan 2007 07:37:01 +0000, Tony 9-5 wrote:

Anyway, can I fit a room stat myself (the job seems straightfoward and
there is provision on the control board by removing a wire link and
wiring the stat in), or do I need to get an approved person to do the
work? Part L seems to refer to new installations.

As there will be mains power to the stat, is this classed as a new
installation under part P of building regs?

Yes central heating controls are notifiable under part P.

In practice it's most unlikely there would be any repercussions to simply
ignoring the regs and DIY-ing it (assuming you wire it up safely
and correctly), unlike say replacing a CU or rewiring a house which might
attract attention and awkward questions when you came to sell.

As to the type of stat you might consider a programmable thermostat which
lets you vary the temperature at different times of day and days of week
e.g. warmer in evening than daytime, cool but not off if it gets really
cold in the night. The Honeywell CM907s (at about £45 from Heating
Controls Online) are the user-friendliest I've found, although the larger
Horstmann one from Screwfix is not bad for about £30. Honeywell also do
wireless versions of the CM907 for about £90-100 which allow you to
position the sensor/control box in the best place regardless of cable
runs. They also do 1-day versions of the CM907s called CM901s and screwfix
do the wired version of this for about £43.