Tado Wireless Receiiver (EU version) + Glow worm Ultracom2 18SXI on EBUS

d4sloth

Hi all,

I purchased a Tado setup to replace my old setup for heating, which was a Honeywell ST9400C + 2 "wireless" thermostats in the house. That connected to a Glow worm Ultracom2 18SXI Boiler, which i believe is a combi. in addition to that, a few years ago when i had solar panels installed, the company who installed it also added a "Boiler Dr" which was modulating the heating i believe.

During installation, i removed the wiring for the Boiler Dr, which was wired into the N/L/E and RT ports on the boiler board. the Boiler Dr was spliced into the middle of the black cable leading into the RT port and on the other end was the ST9400C which it was connected to port 3 which is marked as HWon.

i left the RT port empty and connected cables between EBUS + and - on the boiler and + and - on the Tado wireless receiver as per the guidance on the tado. At this point the boiler was detecting the ebus connection, but the boiler would not fire up. After some further reading, it seemed that a cross connect between the RT and 24V port was required, which i've now added. The boiler does now fire up and shows that its heating up when heating is called for by tado. However the radiators and hot water receive no hot water and fail to heat up.

So in summary, the boiler now has N/L/E connected directly to mains only. RT and FP are empty. + and - ebus are connected to Tado and RT and 24V are looped.

Can anyone help suggest what i've missed or done wrong please? i've asked Tado support who helped update the firmware, but they are now saying the tado device is telling the boiler to heat up and it is, which means i should speak to a local boiler technician...however heating was working on Monday morning this week before making the change....i dont see how the boiler could miracously fail in such a short time.

Any help much appreciated. pictures attached of the install.

Thanks

-Ian

d4sloth

Update - after more reading and research online, I've realised a couple of points...

- The ultracom boiler is actually a system boiler
- the other thermostats in the house are wired back to the honeywell st9400c. Both are two wire only and seem to be part of a two zone system.

Seems at this point that the hot water is not reaching the rads because these valves are closed. Does anyone have any experience with using the eu wireless receiver in setup like this? I read on another thread that the receiver can control one of those zones and so I think I would just need one extra wired thermo stat to control the second zone. I'm not sure how exactly that would be wired in though.

On top of that, I think hot water is mixed in there somewhere too on one of these two off shoots.

Any thoughts would be much appreciated :)