Struggling to understand Tado's heating logic
Hey all! I installed my 2 wired Tado V3+ thermostats last week and it's been a bit of a mixed experience so far. I initially had to go to support because one stat was turning the boiler on and off like crazy and pushing latest configs seemed to fix it. It's been better since then but it's still being a bit weird and I'm trying to understand why. I have recently learned about TPI and PID thermostats which helped me understand some but not all the behaviour.
One thermostat controls my downstairs, which is basically one large open plan room with multiple rads. In the morning the boiler kicks on and heats up the room as expected. Tado allows it to get about 0.5 degrees above target before switching the boiler off. This is all fine but then a short while later it will kick the boiler on again for about 5 minutes and switch it off again. The radiators are still very hot, the room temp is continuing to rise well above target now and the day is only getting warmer. So why would it want to cycle the boiler on for 5 minutes? That just seems like unnecessary wear and won't do anything useful for room temp.
In my research, overshooting target temp and overly frequent boiler firing are common complaints with Tado that people didn't have with other systems.
I'm also struggling to understand "heating to" and the 3 heat lines. "Heating to" doesn't mean the boiler is on and it can still be "heating to" even when it's almost a full degree above target temp. The three heat lines don't equate to boiler firing either, 3 will usually mean the boiler is on but not necessarily, 1 will usually mean the boiler is off but not necessarily and 2 is anyone's guess. Are these only relevant for TRVs and meaningless with wired thermostats? Sometimes it skips level 2 entirely.
I'm aware support can change some values to alter behaviour which is helpful, although I'd be much happier being able to change and experiment with these myself. Does Tado eventually learn and these strange boiler firing behaviours go away?
Answers
-
Yes, you’ll find quite a few older threads about this. From personal experience I’ve often noticed the “one line but not much happening” phenomenon. Is yours a relay controlled system because I wonder whether the three lines are really more relevant to systems running opentherm. I have to say that sometimes I think fondly of a simple bimetallic ‘stat!1
-
Yeah it's just a simple relay control, which is why I also wondered like you if the three lines were just meaningless for this setup.
This morning I got the good old turn on for 3 minutes then turn off, then come on for 3 minutes again 🫠 Half the radiators didn't even get hot yet and my poor old cranky Potterton boiler is probably hating life right now.
0 -
Hello. Unfortunately, the lack of pid settings deters me from buying. Reading the forum makes me lose interest in the whole Tado thing. I have been planning to buy it for several years, but what I read here disappointed me.
1 -
@FreshFromTheGrave I had a similar experience with mine, although my boiler has weather comp so it was basically doing nothing at all in terms of putting heat in the house, but just wasting some gas, If you contact tado support they can adjust the settings so that the minimum fire time will be up to 10 minutes. That way, the boiler should not cycle as much. Also, try turning down the boiler flow temperature if you can (depends on your hot water set up). It'll take the house longer to warm up, but it shouldn't overshoot (tado seems to get bored in the end of trying to take it over the set temperature)
1 -
I agree, the lack of advanced controls is quite annoying because they exist and support can access them, but we can't access them and it's our devices in our homes 😅 It would be better for everyone if we can adjust and experiment with these and see results in real time and not have to bring the results to support who have to interpret them.
I think I'll just get the minimum fire time adjusted to like 15 minutes or something, and maybe the minimum interval to firing again is also 15 minutes. My biggest gripe at the moment is these silly 3 minute cycles, usually when it's already above temp. Like it does absolutely nothing for temperature because I don't even have pump overrun so it's just needless wear on the boiler at this stage.
-1
