Devireg 500 underfloor heating not working

[roo roo]

Hi, I have attached a pic of the display. Pressing the button it twisting either way does nothing. Haven't used it ever and it was installed in the bathroom about 10 years ago.

 

[Taylortwocities]

Your picture shows the stat with a display showing. Does this display disappear if you turn off the power?

What do you get when the power is restored?

 

[roo roo]

Hi, it stays on whether the power is on or off. I'm not quite sure why though.

 

[Taylortwocities]

It’s printed on the screen then.
Do you have a voltage test device? Not a neon screwdriver!
Your next step is to check if mains voltage is actually getting to the stat. Have you checked the fuse?e

 

[ban-all-sheds]

Haven't used it ever and it was installed in the bathroom about 10 years ago.

It'll be a bit tricky to get the installer back if it never worked.

Why do you want to use it now, after 10 years?

 

[roo roo]

We thought we would put it on to see if it works. I remember the installers tested it when the fitted it at the time of the new bathroom so it did work.

I wasn't home last night so will check the fuse today.

 

[ban-all-sheds]

S'pose it's possible that it's just too warm for it to come on.

 

[Taylortwocities]

S'pose it's possible that it's just too warm for it to come on.

I suppose not.
There is much more to the display when the stat is powered up. My suspicionis that the fuse has popped, or the stat has died, or it may just need a reset.
In its powered up state, it should look like this: