Wiring a siemens 7 day timer to underfloor heating

[IR8Matt]

Hi Guys,

I've recently installed some electric undertile heating.

I have a siemens RWB7 timeswitch (http://www.landisstaefa.co.uk/prd/resofacts/rwb7.pdf) and I am trying to wire it in to the thermostat for the undertile heating from a fused spur in the kitchen.

I have tried but failed every time to get this to work. Can anyone shed light on how to wire this up?

Any advice greatly appreciated. I have tried to get a sparky in but he won't do the work which is a '10 min' job for him without checking the whole house over first, which of course will be costly.

Cheers

Matt

 

[plugwash]

presumablly there is a live and a neutral wire (and possiblly an earth too but you just need to connect all earths together and i won't mention them further) from the fcu to the thermostat

connect live out from the fcu to L
connect neutral out from the fcu to N

connect neutral into the thermostat to N
connect live into the thermostat to 4
connect L to 2 with a short link wire

 

[IR8Matt]

Thanks Plugwash,

I think it was the link wire that was throwing me.

I assume I could try this with a light first to check that I have got it all right?

 

[IR8Matt]

OK, that worked a treat, just want to check that I get this next bit right...

In the photo below I have connected as suggested to the timer, now do I connect as follows?

Connect 4 on the timer to 2 on the thermostat
Connect N on the timer to 4 on the thermostat

Then...

L from the undertile heating to 1 on the thermostat
N from the undertile heating to 5 on the thermostat

and the probe to 6 & 7.

Thanks again for your help.

Matt

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[Mug-o-Latte]

IR8Mat,

You didn't mention the thermostat on the original post. I have just fitted the very same thermostat backing plate as part of my undertile heating. The installation instruction for the backing plate are here:
http://www.aubetech.com/english/manuels/TH132_a_f_af_LINE_ENG.pdf

I have a th132 timer for it that just plugs into the front of it (http://www.aubetech.com/english/frameset_floor_heating.html). This provides the timing & the temperature control via a floor thermostat that I buried under the tiles. Did you fit a thermostat under the tiles?

I connected the FCU to L to 1, N to 5, the floor tile live to 2, floor tile neutral to 4, floor thermostat to 6 and 7. This works because the timer is then plugged into the front of the backing plate. In your case it seems odd you have a timer that isn't integrated with the backing plate, so you may want to consider the th132 timer. If not, I'm with plugwash and his wiring. You got it the wrong way around. When you said:

Connect 4 on the timer to 2 on the thermostat
Connect N on the timer to 4 on the thermostat

Then...

L from the undertile heating to 1 on the thermostat
N from the undertile heating to 5 on the thermostat

You got it the wrong way around. The symbol ~ on the thermostat is the supply i.e. the live stuff that comes from the FCU or your siemens timer, and 'Load' is the live circuit that is your underfloor heating cable.

Who supplied you with a timer and thermostat backing plate with no instructions on how it should be wired?!!??

 

[IR8Matt]

Cheers Mug-o-Latte,

Undertile heating supplied by Wickes.

Kit the comprises of that thermostat, which has their name printed on it and the undertile heating. The probe for the thermostat is installed under the floor, just a case of connecting that up now.

I then wanted it to be on a timer, which they supplied also, the siemens RWB7. I did ask if they did an integrated one but they said no... so I take it any further.

Do you think I should consider changing it for the one you suggested even though Wickes say there wasn't an integrated option for their undertile heating.

Thanks again

Matt

 

[Mug-o-Latte]

IR8Mat,
I had a look at the Wickes stuff, but didn't go with it. Can't remember why but the more I use Wickes stuff, the more I run into problems. Tried to silicone seal a shower tray with their own brand stuff the other day and found it impossible to get a smooth finish. So I've gone back to branded stuff.

With regard to replacing your unit with an Aube one, I don't know if you can get just a new front plate for it, or whether you replace the whole unit. I got mine as part of a package from :
http://www.floorheatingsystems.co.uk/Underfloor/Cable_Kits/cable_kits.htm

Tomorrow I turn it on (the adhesive should be dry by then). I did a quick test a few days a go and it turned on fine. It has the timer inbuilt

The timer/termostat has six pins in a rectangle, 2x3, that plug into the backing plate that looks the same as what you have. Do a search for Aube th132F on google and I'm sure you'll find someone who sells the integrated thermostat. I'm still shocked that Wickes don't give you more info that what your have. I almost bought a Wickes system .. glad I didn't.

Have you tried asking for their advice ... or do they play the ... get a qualified electrician card?!

I can't really advise you to change it, as I'm not an electrician, and I don't know what thermostat floor probe came with it, but the backing plate looks identical to the backing plate I got with the th132f, so that suggests you could dump the existing timer and replace it with the th132f. No guaranttees though ...

MOL.

 

[IR8Matt]

Well I'm glad to say that the undertile heating had its first test run yesterday as a complete setup... a resounding success.

No more cold feet on a winter's morning!

Thanks

 

[--tom]

fascinating and timely for me, as a matter of fact, Roger Bisby has an article ref. a bathroom swap in the Sept. 04 issue of "Professional Builder"
but he doesnt really cover the "Dimplex" u/floor mesh heating issues.
Would anyone care to walk me thro the whole process beginning with selection of materials?