Wiring help - heating seems to always be on?

DHC

Hello

After installing my Tado V3, it seems like the heating is constantly on, or as an absolute minimum comes on when the hot water comes on.

In the screenshot the temperature kept getting hotter overnight, even when the schedule was set at 15 degrees. During the night I turned the schedule off, and it kept getting hotter again. When the hot water was scheduled to come on, or got really hot! Ultimately I just turned off my boiler "at the wall".

I think I might have got the wiring wrong, so have attached images of this.

Can anyone help?

https://imgur.com/a/MD5S6rJ

policywonk

Questions.
1.What's the exact model of boiler?
2. What plan is it? S? Y? W?
3. How many wired thermostats ?
4. What was the original model of thermostat being used?

DHC

Thanks for coming back to me. I have an ideal icos HE15 boiler and the original thermostat was a danfoss ret230p. I have replaced this with a single wireless tado thermostat. I have not replaced or changed any of my manual TRVs. I think, therefore, I have an S plan system, as I only have one "some". However I dont know this for certain!

policywonk

@DHC . Hi again. On that basis it seems that

• Your boiler is designed to be controlled with a hard wired on/off system off commands, using mains voltage controls from the thermostat.
• Your Danfoss thermostat has a direct hard wired relationship with the boiler. This is the installation link: Danfoss_087N743000_230P_Room_Thermostat_230v_PDF.pdf. Hence when migrating from that thermostat to a Tado WIRED thermostat, this would be the wiring map
  • LIVE (L) from the Danfoss goes to COM on the Tado
  • NEUTRAL (n) from the Danfoss goes to P1 on the Tado
  • PIN 1 (NO) from the Danfoss goes to NO on the Tado
  • PIN 2 (NC) from the Danfoss (if it is there) goes to P2 on the Tado
  • COM on the Danfoss should not need a wire to be moved on Tado.

One strange thing. You responded stating that you had a single wireless Tado thermostat. I know that all Tado devices talk wirelessly, but the wall thermostat you have needs to be wired. I dont see how it could talk to your boiler otherwise, if you did replace the Danfoss device.

That aside, would you try the following sequence?

1. Go back to your thermostat and carefully confirm that it has applied wiring map described above in your migration. If you need to change it, please do.
2. Then when you are sure the wiring is right, press the round button on the Tado thermostat
   1. It should allow you to see the set temperature and the actual temperature when the boiler is running away again.
   2. Does it show them as different? If it is, the problem is either likely a faulty thermostat or faulty wiring.
3. Using the app, shut down the heating. Does the boiler respond and shut down?
   1. If it does, it means that the thermostat is capable of issuing a shut down command.I
   2. If the thermostat cannot shut down the boiler there is still a wiring problem, but it may now, not be your thermostat - it may be a zone valve that it stuck open. If this is the situation, how comfortable are you with checking wiring? Do you have a voltmeter or electrician's testing screwdriver? If not happy with the electrical issue, best to get an electrician involved.
4. If the thermostat does register temperature differences and is capable of shutting down the boiler, it suggests that the thermostat is partially faulty. Contact Tado support via the App and get this sorted.

wateroakley

Hello @DHC Can you clarify if you used a wireless starter kit, with the wireless receiver replacing the old thermostat and a wireless temperature sensor? Or a wired starter kit with a wired thermosat ?

That information will help @policywonk and others to help you.

EDIT: typo.

DHC

Apologies for the confusion - I have a wireless receiver replacing the old thermostat and a wireless temperature sensor