Trying to wire a Siemens wireless thermostat, please help

[escott81]

I am trying to replace a Danfoss 102e5 central heating control that annoyingly does not have a thermostat with a Siemens RDJ10RF wireless thermostat and C/H control. The connections on the Danfoss look like this (I know there is a loose earth wire i took this just as i started to disconnect it)

Untitled

• escott81
• 21 Nov 2010
• 2

Untitled

• escott81
• 21 Nov 2010
• 2

And the siemens connections look like this

Untitled

• escott81
• 21 Nov 2010
• 2

. Now I have tried wiring the main live to L, connected L to LX, the boiler live to L1 and the central heating pump Live to L2, then all three blue leads to neutral N, and earthed all three earth leads. Can anyone see where I am going wrong because the heating does not come on but the boiler does sometimes but not always when the thermostat is calling for heat? Any help would be really appreciated. I have a potterton Kingfisher cf50 boiler if that makes any difference?

 

[Rob]

Assuming you have some sort of cylinder for HW then your doing it wrong.

The RF stat you have will only control heating. You still need some sort of timing for the HW.

Im guessing by the wiring and the age of the boiler you have gravity HW and pumped CH.

As I said you need a basic timeswitch which will simply operate the boiler. This is also for you HW.

You then wire the stat in just to start the pump. Note if the timeswitch for HW is off then the pump will have no heat to pump round.

Personally I would have left the programmer as it was and bought a basic rf stat and fitted the reciever next to the programmer.

Apologies if I have misunderstood the system set up. If you could confirm what type of arrangement you have (any motor valves etc) I could give you more info if you need it

Rob

 

[dumbrill]

Any help would be really appreciated. I have a potterton Kingfisher cf50 boiler if that makes any difference?

You're not replacing like with like. I think you need to insert the Siemens control in series with the existing CH control. However to use the Siemens control properly would result in the HW being on 24/7. You also need a timer for the HW.

The key issues is that the 1025E "is used with control systems where heating and domestic hot water are required at the same times. The heating can be switched off during the summer". This means (I assume) that You can't have the CH on without the HW.


Edit: I hadn't seen the first reply when I replied, but it makes more sense now with the gravity HW system taken into account.

 

[D_Hailsham]

Untitled

• escott81
• 21 Nov 2010
• 2

Now I have tried wiring the main live to L, connected L to LX, the boiler live to L1 and the central heating pump Live to L2,

Look carefully at the picture and you will see a diagram at the bottom showing how the internal switch works. LX is the common and the switch will either connect LX to L1 or to L2. The way you have it wired, either the boiler will work or the pump, but not both at the same time! The diagram at the top showing a "sun", means that LX is connected to L1 when the thermostat is calling for heat.

So what you are doing is turning the boiler on when the stat calls for heat, but not the pump.

I wont repeat the questions about the type of system (gravity HW etc), but they need to be answered as what you are trying to install may not be suitable.