Paul_Thomas said:
What's special about a Rad allen key? (I have a large selection of std allen keys)
A rad allen key is one that you don't mind seeing damaged and destroyed as you sweat and swear when undoing an impossibly tight rad tail.
What's the regulations on where I have to fit TRV's when having a new boiler installed because of extension? (One person said upstairs only, another said whole house apart from 1 radiator)
I believe the only relevant legal requirement is the following, from the Building Regulations:
[code:1]PART L CONSERVATION OF FUEL AND POWER
L1 Reasonable provision shall be made for the conservation of fuel and power in buildings by—
(a) limiting heat gains and losses—
(i) through thermal elements and other parts of the building
fabric; and
(ii) from pipes, ducts and vessels used for space heating, space
cooling and hot water services;
(b) providing and commissioning energy efficient fixed building
services with effective controls;[/code:1]
Thinking pragmatically, it's traditional to keep the upstairs slightly cooler, so those rads would certainly shut off first, but, since TRVs throughout are an effective way to meet the requirement, you'd have to show that TRVs on upstairs only are an equally effective measure. Many systems require that one rad has no TRV on it, but not all systems.
Do I need to use a reducer, can't I use one of these:-
<list of URLs to TRV products>
Yes you can.
or a selection on here which are cheaper:-
http://www.toolstation.com/index.html?code=75467
Any recommendations on the above TRV's?
Personally I'd steer clear of the 'brandless' products. As ChrisR said, they all go wrong in the end, but you get what you pay for, and it's hard to beat a Drayton TRV for value.
An ordinary valve that is set partly open in order to balance system flow, whose spindle is then shielded with a cosmetic plastic cap, or a screw-on metal shield, to discourage tampering. Some lockshields have a nut that locks the spindle.
On a rad with a TRV the lockshield is a non concept, because the non-TRV is set and left fully open.