Replacing underfloor heating stat with no floor sensor.

[Bobble23]

Hi,

I've not really got involved in underfloor heating before, but a customer asked me to replace her OJ Microline manual stat for her bedroom heating which had packed up with a replacement generic version she got from Amazon. I assumed it'd be a straight swap so said yes and wired it up, the only surprising thing being that there were no wires from the sensor into the stat.

When the power is turned on the red light on the stat flashes very briefly then nothing, and the floor doesn't heat up. Any ideas what's gone wrong? Do I need to get a stat with some sort of temperature sensor in the stat as opposed to using the underfloor sensor, in which case can anyone recommend one?

Thanks.

 

[westward10]

Are you saying there is no floor sensor in place.

 

[Bobble23]

Are you saying there is no floor sensor in place.

Exactly that. No wires from the floor into the back box for the thermostat.

 

[telectrix]

the original stat must have sensed room temp. check how it was wired and see if the new stat is compatible with the installation.

 

[westward10]

If the new stat has sensor terminals I suspect it will not function as it needs temperature feedback from the sensor to control the floor heating.

 

[Bobble23]

Thanks all. Does anyone know of a stat I could get that doesn't need an external sensor?

 

[123]

Heatmiser Neostat-e v2 from what I can recall would work in the setup you have.