V3+ attempting to modulate even though it's a relay?
Hi all! Installed my V3+ wired thermostat over the weekend and this morning was the first day it was cold enough to need to fire the boiler.
Unfortunately it didn't go well :D The boiler came on for 7 minutes then turned off - not reaching target room temp. It stayed off for a while then came on again for another 7 minutes… Sometimes when checking the app settings it will say it can't connect to the Tado servers, so I tried to test it in manual mode.
In manual mode I set the temp to 23 to give it a long required run time. It started off better but then after about 15 minutes I could hear the relay clicking off and on in a rapid interval, which I think might be making the boiler go into anti-cycle? I suspect Tado is trying to modulate the boiler but doing that with rapid on/off switches isn't great for anything, not good for the boiler/pump or reaching the desired temperature.
Is there some way to configure how it tries to modulate the heat or is something wrong here?
The setup is simple, I've replaced an old Honeywell CM907 wired thermostat with the V3+ wired, so just 2 wires and that is for one of two zones at the moment controlled by simple zone valves. Boiler is an old (awful) Potterton Promax SL 18kw, which I believe attempts to self modulate.
Just wanted to check in with other users experiences before I go to support. I've read they can change the minimum firing time but that seems more like a patch than a proper solution. It should just be heating until target temp rather than trying to be clever and switching the boiler on and off every few seconds trying to modulate it.
Best Answer
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Looks like support managed to fix! They pushed the latest configs and that seems to have resolved it. Maybe mine shipped with some wonky settings. I notice that now it doesn't go down to 1 wavy heat line anymore, it stays at 2. I think the problem was it switching between 2 and 1 and that's when it would start to go crazy with switching the relay.
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