Radiator's wont turn off - Danfoss TP5000si Room Thermostat

[Mr Moashie]

Hi,

I've recently moved into a new property with a Ideal Logic 15 Boiler and Danfoss Heating Controls (around 4 years old). The main control unit is in the utility room and controls the hot water and heating throughout the house however, I have a room thermostat programmer (Danfoss TP5000) in my living room.

I've had no problems over the past 3 weeks however when I woke up this morning and went into the living room the temperature was 28 degrees and it should have been 20 degrees.

Essentially the radiators wont switch off no matter what setting I put on the thermostat. If I decrease the temp setting on the Danfoss controller nothing happens, if I increase to over the current temperature say 30 degrees, the little flame icon displays on the screen as if it is turning the radiators on (however they are already on!!)

I've tried resetting the room controller - doesnt work
Ive tried resetting the boiler - doesnt work

The only way to turn the radiators off is to switch the boiler off!

Oh - the radiators do not have the valves on them also.

Can anyone help?

Many thanks

 

[D_Hailsham]

You obviously have a hot water cylinder - right?

Do you have one motorized valve (usually near the cylinder) like this: View media item 5946
or two like this:View media item 11762

 

[Mr Moashie]

Hi, thanks for the reply. I've taken a couple of photos.

 

[D_Hailsham]

Thanks for the pics (saves 1000 words!).

I see three motorized valves (black and white boxes), which means you have one HW zone (pic 2, right valve) and two heating zones (pic 2, the two valves one above the other). The valves have a microswitch which turns the boiler on when the valve opens. The switch has probably stuck closed so the boiler lights even if the valve is closed.

Do you have a multimeter (and know how to use it)?

 

[twgas]

I would suggest one of the valves is stuck open. If it was just the microswitch staying on the rads wouldn't be hot as the valves would be shut, preventing unwanted circulation.
Do you have another room stat and are all the rads staying on?

 

[Mr Moashie]

Thanks for the pics (saves 1000 words!).

I see three motorized valves (black and white boxes), which means you have one HW zone (pic 2, right valve) and two heating zones (pic 2, the two valves one above the other). The valves have a microswitch which turns the boiler on when the valve opens. The switch has probably stuck closed so the boiler lights even if the valve is closed.

Do you have a multimeter (and know how to use it)?

Erm, nope no multimeter I'm afraid

 

[Mr Moashie]

I would suggest one of the valves is stuck open. If it was just the microswitch staying on the rads wouldn't be hot as the valves would be shut, preventing unwanted circulation.
Do you have another room stat and are all the rads staying on?

Hi, thanks for the reply. no I dont have another room stat.....

 

[JohnD]

(Danfoss TP5000)

Not the wireless version, then?

 

[twgas]

What about the rads, do they all stay hot?
Are both the pipes, to left of the valves, hot or just one or even neither?

 

[D_Hailsham]

Do you have another room stat and are all the rads staying on?

Mr Moashie: An answer to the second question would be helpful.

You said that the living room was 28C when it should have been 20C, but you didn't say what the bedroom temperatures were like. Were they also much higher than expected?