Hello, I have a Nest 3rd generation with S plan. It’s been fitted for around 3 years. All is fine or so I thought but I have a My Energi Eddi now linked to the immersion tank (system boiler with old hot water tank).
I have programmed the Nest to only heat the hot water at 6pm so if it’s been a poor solar day it tops it up with the boiler and this is then hot for the following morning but of course solar can chip in.
My issue is I cannot turn off the hot water demand with the Nest. I’ve turned off the schedule, (I need it on for 6pm as mentioned above but turned it off to try and get rid off the hot water demand). I’ve turned off the legionellae option as well. It says water off and the home away function is disabled as well.
Terminal 6 is constantly live with no hot water demand. I have turned off the heat link, and from the live input supply, there is continuity to terminal 6 so is the relay stuck closed? Does the nest work with I’m assuming two relays, one for heating and one for hot water, are these normally open until the Nest requests a demand?
My readings are with wires disconnected, I suspect it’s a faulty relay in the heat link but it’s most annoying having the boiler kick in when I’m sending 2.5 Kw back to the grid when the immersion could be doing it.
Nest was designed before this solar PV took off, I can see myself going back to a traditional controller as the Nest is trying to be too clever maybe?
Any thoughts would be greatly appreciated.
Regards
Chris
