Replacing a room thermostat - mechanical to digital

Charnwood · 1 Nov 2012

Not too far from Newark is the in-bred centre of England, so I'm told.

The actual centre of England is somewhere between Leicester and Coventry IIRC.

Terry7556 · 1 Nov 2012

in-breeding isn,t exclusive to newark

Charnwood · 2 Nov 2012

Not Newark exactly, a few miles west.

Charnwood · 3 Nov 2012

mfarrow said:
You should connect the brown to A and the green/yellow to B. Put the blue in a connector block somewhere safe.

......assuming everything at the thermostat end is plastic, it will comply.

Done all that and..........

IT LIVES!!! Half an hour in and all seems hunky dory. A couple of test 'boosts' up and down and the boiler seems to be obeying orders.

WTF can I get brown sleeving? Wickes seem to do just G/Y, B&Q G/Y or blue.
Might have to accost a sparky for some.

mikep723 · 29 Dec 2014

D_Hailsham - Many thanks for the wiring instructions to replace three wire dial thermostat with digital two wire, red=A; yellow=B; blue=isolate in connector , boiler now fires up without long delay and house stays warm. Excellent advice!

MarkT1967 · 13 Jan 2016

Hi guys, I'm looking to do the same thing as the op, is it still the case of using the Honeywell? I'm looking to set a maximum on the upper temperature as my kids like to roast at 25degrees lol, I had the old RTS1 set to around 21degrees, this worked well until the clip broke so I thought instead of changing the stat to the same, I found this site and thought hey why not go digital.
Thanks
Mark

thechief1979 · 23 Jan 2018

Hi all, just bumping the question from MarkT1967m - is the DT90E still the preferred replacement for the RTS1?

I have a Heatrae Sadia Megaflo with a drayton programmable controller - is the DT90E suitable?

many thanks

stem · 23 Jan 2018

You can replace a RTS1 with a DT90, whether it is preferred or not is entirely up to you. You may wish to replace a Ford with a VW, others would prefer to replace their Ford with a Vauxhall. All thermostats have the same function they are simply switches they turn the central heating 'on' or 'off' and that's it. [Nothing to do with the Megaflo that's for the hot water]

The difference with the DT90 to the RTS1 is that the DT90 has a display and so is battery operated to maintain the display when the programmer switches off the power to the thermostat.

The RTS1 connections are:

As the DT90 is battery operated, it doesn't need a neutral, so the wire in the N terminal shown above should be isolated / insulated and tucked safely out of the way. The remaining two wires in 'L' and 'Call for Heat' would be connected to the DT90E as follows:

RTS1 L = DT90 'A'
RTS1 Call for Heat = DT90 'B'

Keithmac · 23 Jan 2018

What's the main benifit from going from mechanical to digital thermostat if you already have a digital programmer?.

stem · 23 Jan 2018

Digital thermostats are more accurate than the old mechanical devices, and so maintain a more stable temperature. They also display the actual and set temperatures digitally, which may or not be an advantage to you personally.

A programmer is a different device and serves a different purpose. It is just a time switch that turns the heating on and off, as well as the hot water, if you happen to have a system with a hot water cylinder. It has no control of the room temperature.

diynot

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Replacing a room thermostat - mechanical to digital

Similar threads