No hot water
Hey all, I'll try to keep it brief - I am (slowly) trying to resolve the issue with support but figured I would also ask here in case anyone has suggestions or quick fixes.
Background:
New tado user, new install. UK wireless starter kit plus 6 smart TRVs.
S-Plan heating system with 2-valves upstairs in the water cylinder cupboard.
Replaced Drayon LP241Si timer and thermostat.
Followed all the app instructions, wired up as suggested. During install it said that if 2 (CH-NC) or 1 (HW-NC) are missing then just skip them. 2 was missing, 1 was there.
Issue:
Radiators work as expected. Hot water doesn't work at all.
When heating is being called for, receiver light turns on, clicks, boiler fires up.
When heating is being called for and then water is being called in addition, the water light comes on and clicks, boiler stops firing/light goes off.
When only water is being called for, light turns on, clicks, boiler does absolutely nothing.
In all cases the valves upstairs are opening and closing in reaction to the lights/clicks on the wireless receiver, it's just that the boiler isn't firing up when water heating is being called.
One thing to note is that prior to installing this the timer wasn't behaving as I would have expected (although it's a new house and I've only ever had a combi boiler before so I'm not experienced with this kind of system). Prior to installing the Tado I noticed that the hot water wasn't following the programming/timings that I was setting on the Drayton timer and was coming on (I assume) whenever the cylinder dropped below the cylinder thermostat temperature). Maybe there is a pre-existing wiring mistake that has just carried over?
Any initial thoughts before I share wiring pictures please?
Andy
Best Answers
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I don't have an explanation for the wiring, but based on the photos it does look like S-Plan.
In the photo of the Drayton backplate I can see 2 wires going to terminal 1, but in the photo of the Tado backplate I can only see 1 wire in HW NC. If I'm seeing this right there's a missing wire?
Edit: Also, what have you done with the old wall thermostat?
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I suspect someone needed to join two wires together and used terminal 1 out of convenience. If you have a piece of terminal block it's probably safer to join the HW NC wire to Live without using the Tado wiring terminal.
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Answers
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Your description doesn't make sense. You state it's S-Plan because you have two valves. But your description of the wiring indicates it's Y-Plan. I think you'll need to post some photos of the zone valves and wiring.0
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Pictures attached. Valve on the left opens when heat is called, valve on right opens when water is called. Is this S-Plan or am I mistaken?
Timer wiring before I started the install
And wiring after wireless receiver installed
The boiler boiler wiring
And finally the instructions followed
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Good spot. Looking at the many pictures I took during the process, it appears that there was a pre-existing bridging wire between from what I can make out L and 1 on the drayton programmer (and I have the bridging brown wire left over).
I can't be 100% sure from the pictures though. Is there any risk of damage by trying to connect Live and HW-NC on the tado backplate?
Edit: I have increased the brightness of one of the photos and can confirm that L and 1 were linked on the drayton programmer
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It's only gone and worked! 😁
Thank you so much for your help, I could easily have been trying to figure it out for days.
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