OTN-1991 Thermostat
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OTN-1991 Thermostat

by kwiseman » Sun Mar 01, 2009 10:22 pm

Hope someone can help. I have had to buy a new thermostat for my underfloor heating but can't remember which wires went where.

I have a L and N from the mains
From the underfloor heating, I have one cable with a blue and green/yellow(I persuming is Earth but there is nothing on the instatlation diagram showing where earth would go) and another cable with Brown and again the persummed earth.

The diagram on the instatlation is not clear. The manual so you can see connections can be found if you Google "elektra-underfloor-haeting.co.uk" and then view the pdf area for "otn-1991 manual.pdf"

Hope someone can help urgently.


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by sparx » Wed Mar 04, 2009 9:23 pm

looking at drawing then line into term 1, Neutral in 2, heating mat brown & blue into 3 & 4 respectively, sensor wires go to 6&7 term 5 is for timer input if used or linked to term 1 if no time switch fitted.
earth screen of mats cables must link to mains earth in term block possily in back of stat.
screens MUST be earthed and circuit MUST be RCD protected,
regards SPARX

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