Tado Wireless Receiver and Morco Combi Boiler Wiring Issue – Heat LED On, Boiler Not Firing (Sanity

teller_light

Tado Wireless Receiver and Morco Combi Boiler Wiring Issue – Heat LED On, Boiler Not Firing (Sanity Check Needed)

Hi everyone,

I’ve been experiencing an issue with my Tado Wireless Receiver and Morco combi boiler setup, and I’d really appreciate it if someone could sanity-check my wiring.

The system worked flawlessly for about a month, but recently the boiler doesn’t fire up even though the Wireless Receiver heat LED lights up. Here’s what’s happened so far:
1. Initial Issue: The boiler stopped firing even though the heat LED on the receiver was on.
2. Temporary Fix: I deleted the Wireless Receiver from my Tado setup, re-added it, and it worked perfectly for a day. However, the next day, the issue returned.
3. Boiler Test: I’ve manually bridged the RT terminals on the boiler, and the boiler fires up, so the issue isn’t with the boiler itself.
4. Possible Pattern?: I feel like the issue occurs when I leave the house—maybe I’m being paranoid, but it seems to stop working after I’ve been away for a while. Could this be linked to geofencing or another feature in the Tado system?

Here’s my setup:
• Boiler: Morco combi boiler
• Tado Receiver Wiring:
• Live (L) and Neutral (N) wired to the boiler for power
• COM and NO connected to the RT terminals on the boiler
• Pre-fitted link wire removed from the boiler RT terminals

I’ve attached pictures of the wiring at the boiler, Wireless Receiver and the boilers wiring guide for clarity.

Questions:
1. Does my wiring look correct for this setup?
2. Could a faulty relay in the Wireless Receiver cause the issue, even if the heat LED lights up?
3. Is there anything else I might be missing in the configuration, especially if the problem is related to me leaving the house or geofencing?

Thanks so much in advance for your help—I’d really appreciate your insights!

siallwhite77

I have same issue yet when I run a tap it all kicks in and rads get hot. Been told nothing wrong with boiler. I can't advise on wiring but if it's worked before I think all this must be a app or signal issue. Interested to know if yours kicks in when a tap is run?

teller_light

Yeah tap is fine. That fires boiler ok

siallwhite77

Strange? Nobody can get to the bottom of this and I don't know what to do

teller_light

I do wonder if my wireless receiver is broken.

I see the heat LED on the wireless receiver come on and off according to the schedule, so I know that part is working. The issue is it doesn't fire the boiler. But if i bridge the COM and NO on the boiler, it fires up.

I will listen to the wireless receiver to hear if there's a click when I call for heat, as someone mentioned that maybe a solenoid is sticky in there.

teller_light

I mean a relay, not a solenoid*

Dave62

Hi, I have the same problem with the boiler not firing when the heating LED is on, but my setup is a boiler and hot water tank rather than a combi boiler. The problem is intermittent and I’m pretty sure not related to geo-fencing because I don’t use that functionality.

I also suspect something in the wireless receiver but haven’t had a chance to swap it out. I installed the system in September 2022. I can get round the problem by firing up the hot water as well.

I’ll post again when I get a chance to swap it out.