Horstmann RFT1 Thermostat.(as i can tell you guys love them)

Hello
i've been reading up a bit on this thermostate and its definately not got much applause any where on the internet but im kind of stuck with it after buying it and not fitting it a few years back.

2 years ago i was confident in replacing the room thermostat on the wall.

Today i thought id be smart and thinking it was just a case of relocating the control centre onto the ends of the thermostat wire ( i haven't lost the old thermo wire as i need to back track my paces if this doesn't work out and the old thermo wire is lost in the construction of walls etc.

So i've replaced the old thermo with a 3 core ( in my hand) and long enough to reach from the wire loom to the control centre.

My system is a back boiler, had it about 20 years.

i've added some pics as i now realise its not just a case of swapping.
I do get a red light and a green light and the 2 pieces are talking to each other. I get the green light and The control unit clicks and then theres nothing else so thats where im stuck.

Hoping the photo will help someone with a clear reply as its often hard to disect one persons view to your own.
Thankyou for reading

1st pic.

Loom and the wire bottom right thats red /black and yellow is from the wall thermo.
(The house has been rewired but not that one as its "in the walls")

2nd pic
Full Wire loom central heating system

3rd How
The wires were on the wall thermo

4th Diagram for the new wireless thermo

SORRY i thought the photos would come up from the Album..ive uploaded them.


If anyone could tell me how many wires and which numbers on which sides to alter or anything that would enlighten i would be so greatful.

Electriction has to be my last resort as like everyone ...very broke hence fitting this now as really need more control on the fuel. i've put it off long enough hoping it will get done.

thanks again

 

Thank you

 

You need to connect the receiver to L, N & E from the 240V supply and

the red and black on the present thermostat to Com & NO.

Remove link for this arrangement.

 

Thankyou ive just uploaded a couple more photos of the other end of the wires in the loom

I know the pumps the round brown piece and theres also a Hooneywell square silver object that has seperates my hot water and heating choice.

So the 240v part you advise would be the amped box next to the timer.

The timer has 2 wires comming from it, if thats the case i wouldnt know which one to use so I would stop here.

Unless i had a way of identifying it.

Just need to add that im leaving the old therm reader wires in the wall, so i need to replace them and attach them from the wire loom to the unit as you describe above ...hope thats right

 

That doesn't matter.

You have to identify which of the cables (at the wiring box) goes to the thermostat.
Cut this cable so that it is long enough to reach the receiver then
Red to Com and Black to NO plus E to E.

Then connect a new piece of cable to the L & N plus E on the receiver.
The other end of this new piece to L, N & E in the wiring box.
E is 3, N is 4, Edit - Test for permanent live

 

Thanks again I will get on to it tomorrow now with daylight

 

I'm a bit concerned about the top two grey cables.

One seems to have two reds and a black.
If one of these reds is the cpc (earth) sheathed red then this is not correct and should be rectified - replaced with 3 core & earth.

The other has only a black & cpc.
In effect a single & cpc which may be alright.

If that is so then the present thermostat cable must be the bottom right grey cable.

You should make sure before changing anything.

 

The old wall thermostate at the bottom of the stairs is a the red black and Earth covered one. ( still old due to being in the walls of the house) this is definately the wall thermo wire.

The house was rewired 4 years ago thats the only wire in the house that stayed to my knowledge.

Your discription with the E is 3, N is 4, L is 5 connections is that the numbers on the big black wire loom?

as the picture with the black and red wire in to the white thermo block is just the old thermo reader down stairs

which is going to be obselete.

Im going to wind the red and black wire up at the big black loom end, so at any later date its needed in an emergency of wireless breakdown then i still have it there to reconnect.

 

Ok

Yes, but I was mistaken about the permanent live being no.5.
I have edited my previous post.
You will have to test to determine which is the permanent live.

Ok - use a new piece instead.

 

cool all in place then thnak you again will update the result , realy am greatful

 

As your main switch is next to the existing programmer you may not actually have a permanent live in the wiring box.

However, as you will be controlling the CH from the new thermostat with timer you will have to set the existing programmer to CH ON permanently.
So, to power the receiver you will have to use the terminal (in the wiring box) which becomes live when the existing programmer is calling for CH - no 10 ?

Here is the conventional wiring diagram (but not as yours is wired)

 

Hiya thank you for more discriptions.

Just back from B&Q and wire is only sold in packs of 5 meters so i will have to wait to visit Wilkinsons. As £8 is a joke for a meter that i need.

Unless this is an ordinary wire Eg. like off of an Exstension lead? between me and my friend we have a few rolls of wires stored but I know it can depend on its ability to run the power through it.

I did thou pick up a voltage tester which states up to 250V its the see through pen type screwdriver....my Grandad had one of these and i realy dont like the thought of using it as touching lives is not in my train of thought atall! with any object.

I was thinking is there a way to test for a constant live by fixing it to say an un switched 3 pin socket and if it works its live if it doesnt its not constant....or am i talking absolute twaddle?

Anyway so no wire at the moment and plastic tester.

BUT...

With your last post EFL i see that as power into old controller , old control has a set instruction for a time and then activates sending a power surge down a wire to open up and activate CH.
Its the Wire that gets activated that i am looking for.

As the old programmer will be constantly asking for CH the New control panel will accept its call or refuse its call by the times and days set in the wireless hand held devise.

Do you mean that the wire that is calling for CH is no 10 on the loom .
Thanks

Just an update
Only 2 power wires are entering the loom bottom both greys.
1 is the old thermo and teh other the pwoer supply.
This is a 3 core Red ,Black ,Earth
Which meets top right grey a 2 core
Black and Earth at Number 5 on the loom.

Seeeing as that is the only Power Supply i can see coming in may i be right in saying that the wire from the old Programmer at 5 is the constant live and the other wire from old control
3 core 2x red and Black would be the calling wire

 

But you'd have 4m left over to sell.

Yes, that'll do - in good condition.

No, throw it away.
You need a multimeter, at least, but they are a few pounds.
You really do need one to do electrical work.
CLICK
not a recommendation - just the first that came up.

No, you don't want to take the wiring centre apart.

You could connect an inspection lamp to the relevant terminals.

Yes, the one for CH.

Yep.

It should be.

 

EDL i was just adding this update above

After looking at the loom
Only 2 power wires are entering the loom bottom both greys.
1 is the old thermo and teh other the pwoer supply.
This is a 3 core Red ,Black ,Earth
Which meets top right grey a 2 core
Black and Earth at Number 5 on the loom.

Seeeing as that is the only Power Supply i can see coming in may i be right in saying that the wire from the old Programmer at 5 is the constant live and the other wire from old control
3 core 2x red and Black would be the calling wire

AS you advise no 10 it should be that Red one then
Sorry just need to clarify now the need for the live has changed do i still remove the Link?