Help Wiring new Digital Room Thermostat

[fashp]

I have a problem in being able to wire in two new Room thermostats I purchased to replace the cheap dial version in my new built home. The problem is the current ones have three wires where the new ones seem to only require 2 ?

The Central heating system has two zones, one covering the ground floor and the other the upper levels, each controlled by a MYSON MRT1 room thermostats. There are 4 three wires as follows
Position 1 (L) Brown
Position2 , unused
Position 3 (?) Black with Brown Sleeve
Position 4 (N) Blue

The new thermostats i brought are HORTSMANN DRT2 with three terminals labelled, NO - COM - NC

I have tried a few variations and each time blow the 3amp fuse by the control panel, so I now wondering if DRT2 is suitable.

The central heating system is gas / radiators and the boiler is a gloworm hx30i . Many thanks for any help

 

[RF Lighting]

Wow! How wierd is that!

I actually looked in the Wiki, and there it was: an exact step by step guide with photos to show you exactly waht you want to do.

Isn't that amazing?


//wiki.diynot.com/electrics:how_to_replace_a_room_stat

 

[breezer]

use brown and black (with blue sleave) in com & NO

doesnt matter which way round

the blue, put it in a choc bloc, its not needed

 

[RF Lighting]

use brown and black (with blue sleave) in com & NO

This should read "use brown and black (with brown sleave) in com & NO"

 

[fashp]

Thanks to you both, this makes sense as I was assuming that the (Blue) neutral was needed. Apologies for not searching the WIKI correctly Will do in future. Thanks again.