Mystery controller

[jim567]

Just moved into a house which has a device on a bedroom wall that looks like a thermostat but has only one connection - a bare wire which is wound inside and emerges to run up the wall then out of sight behind a wooden panel. Can anyone help me identify it?

The device has a dial with the thermostat-type markings - frost then 1 to 5. There are no other markings or labels visible outside or inside the casing.

If it's related to some type of panel heating or hot air system, then it's probably obsolete. New CH boiler and radiators were installed 3 years ago. It would be nice to know before I cut off the wire!

 

[45yearsagasman]

It sounds redundant, but to be more accurate, perhaps a picture? I would advise against cutting until sure as to what you have.
That bare wire maybe a capilliary tube from some sort of remote TRV type control.

 

[jim567]

The wire seems quite a fine gauge. The pictures show the device with cover removed.

http://media.diynot.com/209000_208552_66598_27700131_thumb.jpg
http://media.diynot.com/209000_208552_66599_75380748_thumb.jpg

The wooden panel has a 1 inch air gap at the top (below a window sill), as if for warm air circulation. With the restricted view, I can't see any device behind the panel.

 

[Fluffster]

As Gasman said it is a remote control for a trv.

Pete

 

[jim567]

OK, thanks. The nearest radiator is on the other side of a partition and there's nothing attached to the TRV there. The old rad must have been removed from behind the panel. Don't know why the installer left the remote control behind.

Would it be re-usable? Do they only work with certain types of TRV?

 

[Charnwood]

TRV bodies were used as cylinder stats with a phial in a pocket, normally in Elson-type tanks.
Could this be a linked remote control for something similar?

 

[jim567]

TRV bodies were used as cylinder stats with a phial in a pocket, normally in Elson-type tanks.
Could this be a linked remote control for something similar?

Next to an obsolete cylinder in the house eaves, I do actually have a Danfoss TRV body, but the tubing goes in the opposite direction, into an adjacent bathroom. The new bathroom rad has its own valve, so I suspect the Danfoss is also obsolete - maybe for the old bathroom heating system.

Comparing the two controllers, the tubing on the Danfoss is much thicker than that from the "mystery" one. It's hard to believe the latter one is hollow - it's only about 0.5mm in diameter. Is there any other type of controller mechanism, one using electrical resistance, for example?

 

[cozzmic]

It will be the Danfoss remote TRV head. The newer ones wire is about 0.5mm thick and the older ones were thicker. Probably redundant as it would fix onto the dedicated valve with an 2mm allan screw. If you find the other end it has a little bellows to push the pin shut on valve.

 

[jim567]

I found the other end of the Danfoss TRV. It looks like a remote sensor and it was lying behind the bathtub. The TRV must once have been connected to pipes serving the old bathroom radiator.