Help installing DT92E Wireless Stat

cmulhere · 9 Oct 2010

Hi all,

I am trying to install a Honeywell DT92E to my exisitng system.

At the moment I have a wired stat (Servowarm) which has a 3 core and earth cable connecting to it from a Honeywell Wiring Centre. Only two of the cores and the earth are being used at both ends. (Yellow, Red and Earth)

I have removed the servowarm stat and put the receiver in it's place for the sake of testing this.

Have connected the live and nuetral and linked from L to A.

The live and nuetral in the honeywell wiring centre are connected to the room stat connectors 1 and 3. E for the earth, terminal 2 is empty.

I have managed to install the reciever and get the relay working OK, and when you adjust the temperature the relay opens/closes and you see the wireless display call for heat with the flame symbol.

The trouble is, the boiler does not fire up.

The programmer is a Danfoss FP715, the boiler a Potterton Suprima 50L

I appreciate you probably need more info, so tell us what and I'll try my best to answer!

Thanks in advance,

Chris

D_Hailsham · 9 Oct 2010

cmulhere said:
Have connected the live and nuetral and linked from L to A.

The live and neutral in the honeywell wiring centre are connected to the room stat connectors 1 and 3. E for the earth, terminal 2 is empty.

Presumably the wire connected to terminal 3 is blue, so you have assumed it is a neutral. It isn't - its the switched live to the boiler.

I have managed to install the receiver and get the relay working OK, and when you adjust the temperature the relay opens/closes and you see the wireless display call for heat with the flame symbol.

The trouble is, the boiler does not fire up.

You need a wire from terminal B back to the wiring centre.

Connect as follows:

Wiring Centre Live (usually T1) to L
Wiring Centre Neutral (usually T2) to N
Link L to A in the receiver
Connect Receiver B to wiring centre's Boiler ON terminal (usually has an orange wire connected).

cmulhere · 9 Oct 2010

Thanks D_Hailsham!

Before i get the screwdriver back out, can you check out the picture which should help me understand things.....

At the moment on the room stat wiring block of the honywell wiring centre, T1 is a yellow wire, E is the earth, T2 is empty, T3 is a red wire. There is a blue core on this cable which isn't connected to anything.

I currently have the yellow wire connected to N in the receiver, with the red wire connected to L. As mentioned previously A and L are looped.

Is this a case of connecting the blue wire to B in the receiver and then to somewhere in the wiring centre...

If it is can you let me know the number and location of the terminal in the wiring centre. Should I be using the T2 on the room stat block, or the L or S/L on the boiler block?

Thanks so far for your help - I'm almost there

Homeywell Wiring Centre

cmulhere
9 Oct 2010
1

D_Hailsham · 9 Oct 2010

I did not realise that you had that type of wiring centre, so my terminal numbers are wrong.

cmulhere said:
At the moment on the room stat wiring block of the honeywell wiring centre, T1 is a yellow wire, E is the earth, T2 is empty, T3 is a red wire. There is a blue core on this cable which isn't connected to anything.

Disconnect all wires to the existing thermostat and to the "Room Stat" terminals in the wiring centre.

Connect Red wire to Wiring Centre "programmer" L terminal
Connect Blue wire to programmer N terminal
Connect Yellow wire to Wiring Centre "Room stat" terminal 1
Connect Earth wire to "Room stat" terminal 3.

At the receiver:

Disconnect link between L and A
Connect Red wire to Terminal L
Connect Blue wire to Terminal N
Connect Yellow wire to Terminal A
Connect Earth wire to Terminal B

The earth wire should have a red sleeve or red insulating tape wrapped round it to show that it is a "live" wire.

cmulhere · 10 Oct 2010

D_Hailsham,

I can't thank you enough - you are fantastic!!

All up and running as per you last post. I took the option of ditching the old cable and runing 2 new twin core cables, which saved me having to use the Earth as Live, and made for a simpler job of wiring up the receiver, which is set up for 2 cables.

Thanks again, your help is more than appreciated!

Kind regards,

Chris

cmulhere · 10 Oct 2010

OK, I spoke too soon!

Have wired this up as you suggested and all appears to be OK, the call to the boiler is being made, but the boiler does not respond.

That could be because I made a mistake when connecting the wire in to the honeywell wiring centre. I mistakingly put the wire form B to terminal 2 of the 'Room Stat' instead of terminal 3.

This blew the fuse in the switched fused spur when I put the power on. I have replaced the fuse and re-wired correctly.

Could I have blown another fuse somewhere?

Just to confirm the wiring...

Receiver L to Wiring center Programmer L
Receiver N to Wiring center Programmer N
Receiver A to Wiring center Room Stat 1
Receiver B to Wiring center Room Stat 3

Cheers,

Chris

picasso · 10 Oct 2010

There is another fuse on the pcb in the boiler, could be worth checking you havent blown that as well.

cmulhere · 10 Oct 2010

Would this fuse just control the CH or Water as well, because a call for hot water is still working OK.

Regardless, I couldn't see the fuse on the boiler PCB, but in fairness, unless it looked like a conventional fuse, I may well have missed it.

There is a 2amp glass fuse in the honeywell wiring centre, this looks OK, but am unable to test it (or replace it as I don't have any spares)

Any more suggestions?

D_Hailsham · 10 Oct 2010

cmulhere said:
I made a mistake when connecting the wire in to the honeywell wiring centre. I mistakenly put the wire form B to terminal 2 of the 'Room Stat' instead of terminal 3.

This blew the fuse in the switched fused spur when I put the power on. I have replaced the fuse and re-wired correctly.

The wiring, as you gave it, is correct.

Terminal 2 is a neutral, so you would have effectively created a short.

Do you have a multi meter? If so, here are some tests. Set the meter to AC volts.

Disconnect wire from Roomstat terminal 3.

With the stat low and CH on at the programmer, measure voltage between Room stat 1 and Programmer N: it should be 240vac.

Measure between RS3 and Prog N: it should be 0V.

Now turn the room stat high so the light comes on on the relay. Measure between RS3 and Prog N. It should be 240vac. If it is, the problem is in the boiler; if it isn't the problem is in the relay.

PS Just read your latest post. If you can get HW but not CH the problem is probably that you have blown the relay. Testing with the meter will tell you.

If you don't have a meter, connect Roomstat terminals 1 and 3 together. If you now get heating, the relay is definitely blown.

cmulhere · 10 Oct 2010

OK - panic over. When taking a look at the boiler PCB, i noticed that the programmer (on the wall beneath the boiler) was at a slight angle, so being the anal git that I am, I straightened it a bit , and hey presto, the boiler kicked in.

Have played around with it all all appears to be fine now.

I must have knocked the controller slightly when changing the fuse earlier.

cmulhere · 10 Oct 2010

Thanks D-Hailsham,

I didn't see you post, must have ben typing mine at the same time.....

On a seperate note, I am looking at replacing the Danfoss FP715 for nothing other than asthetic reasons, it's looking a bit shabby and I would prefer a white programmer to match the other kit.

Any suggestions? One that is easy to replace, I am correct in thinking that most will use the same backplate to avoid having to re-wire?

Thanks again.

Chris

D_Hailsham · 10 Oct 2010

cmulhere said:
On a seperate note, I am looking at replacing the Danfoss FP715 Any suggestions? One that is easy to replace, I am correct in thinking that most will use the same backplate to avoid having to re-wire?

The Honeywell ST9400A (1 day) or 9400C (7 day) is a direct swop.

Milky01 · 1 Feb 2013

Hi There

I know this is an old post but, am I right in thinking that terminals AB&C on the Honeywell DT92E are simply the relay switch terminals and therefore can be used to a 24v or 240v system?

Cheers

doitall · 1 Feb 2013

Milky01 said:
Hi There

I know this is an old post but, am I right in thinking that terminals AB&C on the Honeywell DT92E are simply the relay switch terminals and therefore can be used to a 24v or 240v system?

Cheers

C isn't used for heating, but yes they can be used for volts free or 230vac

Milky01 · 1 Feb 2013

Thanks Doitall for such a quick reply it's much appreciated -

I see you're in Bath as well...

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

Help installing DT92E Wireless Stat

Similar threads