Ideal Logic Combi 30 boiler and Danfoss TP500Si (Wireless) - heating not turning off when temp is reached

[DetlefSchmitz]

That certainly looks like the wireless version and RX1 should be the receiver. The LED over CH1 should follow the flame symbol on the thermostat. Next time the boiler is on when it shouldn't be, check that led. The receiver could be being influenced by another radio signal or just be flaky.

 

[JoRDillo]

Thank you. I will definitely check that. And I'll update this thread with photos if / when it turns on, or stays on, without being asked. I appreciate your help. As a non-technical woman, these things make me worry.

 

[ianmcd]

I have 'something' in the boiler cupboard that's linked to the Danfoss wireless panel downstairs. The boiler and thermostat are currently behaving which is so frustrating...yet nice too....but I know that it'll go wrong any moment. Here are the pics of the thermostat and the one located by the boiler. I may have to wait a while for things to go awry with the heating. It was fine last night and then just decided to heat up in the middle of the night.

Then you have an RF it does make a difference

 

[ianmcd]

And is the boiler running when you took those two pics ?

 

[JoRDillo]

No. When it's running the CH1 lights up and I normally get the flame icon on the thermostat. Although the flame hasn't been showing the past few nights when it's been showing as 17 degrees yet the room is like a furnace. It's running well right now, so I'm keeping an eye to see if it goes wrong.

 

[polesapart]

O.P. You can of course switch off the heating at the boiler. Just turn the right hand knob on the boiler fascia to the tap symbol position.

 

[ianmcd]

No. When it's running the CH1 lights up and I normally get the flame icon on the thermostat. Although the flame hasn't been showing the past few nights when it's been showing as 17 degrees yet the room is like a furnace. It's running well right now, so I'm keeping an eye to see if it goes wrong.

That is why I asked for pics of everything at the same time when the boiler should be off but is actually running, only way we can tell you if it is the controls or the boiler

 

[JoRDillo]

Yep. That's what I have resorted to over the past few nights. Thanks Polesapart

 

[JoRDillo]

Ianmcd, I understand. I'll hang fire until the error happens again and I'll take photos. Thank you!

 

[dilalio]

If the light is on at the receiver then it will fire the boiler, regardless if the receiver is sending it or not.
If the light is not on but the boiler is running and heating the rads then the boiler is getting a live supply on its switched connection from "somewhere"!

 

[RandomGrinch]

If the light is not on but the boiler is running and heating the rads then the boiler is getting a live supply on its switched connection from "somewhere"!

And as you said earlier the relay could be sticking - the LED wouldn't illuminate in that case.

The OP could give the RX1 a sharp 'tap' and see if the heating switches off.

Otherwise, the RX1 could be removed completely, if the boiler is still on, then there is definitely an issue elsewhere!

 

[ericmark]

Two things, I had this thermostat which gradually lost the RF link, and would not always fail safe, this

was designed to fail safe, and if no signal received every ½ hour it would close down, not read instructions for your thermostat.

But the second is, even if it does stick on, the TRV's should stop any over heating, the boiler may start cycling too much, and unless using a programmable type then they only have one setting night and day, the one shown however can be programmed, and at £15 each in 2019 it seemed the sensible thing to do.

But for rooms to over heat there must be at least two faults, as well as wall thermostat the TRV's and/or lock shield valves must also need adjusting or renewing.

I am not saying the wall thermostat does not need fixing, as in the summer unless fixed the boiler will be cycling all day, but there must also be a secondary fault.