Boiler crashes with error, when tado tries to heat boiler and shut off radiators at the same time
Hello. I recently switched to tado.
I have 7 radiators with tado thermostat values. I have one wall thermostat in my living room, which is connected to the boiler using the existing wires from the old thermostat.
Since I switched to tado, my boiler have shut off very frequently with error E1 and E2. I thought it was due to sensors in the boiler, so I called a technician, and paid 450€ for servicing my boiler. Already next day it shut off again and my frustration sky rocketed. I called the service company and they were very confused how I could still get errors, everything should be fine.... After some talking, I get to talk to a guy who asks my if I have tado vales..... And I told him yes, I recently switched because I wanted to save on energy by scheduling my heating.
He then said: I think there's a problem with your setup, tado is telling the boiler to heat, but at the same time it's shutting of almost all of the radiator valves, this can happen if you want to heat just one room for example. or it can happen if you are trying to heat two rooms, but one of them meets your chosen temperature, and the valves are shut off for a while, but the other room still needs some more heat, so that single valve is fully open, and the boiler is heating at max to get heat up in that room.
He continued: if it's a small room like a bathroom, then your radiator most likely can not give off much heat, and the water returning to the boiler is near the same temperature as it was when it left the boiler (it doesn't cool off enoug) this causes the boiler to shut off with an error.
He then said: To test if this hypotesis is right, please remove one of the tado valves from your bedroom, so that radiator is always fully open. This should ensure that at least 1 radiator can give off heat when the boiler is told to heat.
I tried this for 2 weeks; I removed one valve from my bedroom, and I didn't have a single error in those two weeks. Yesterday, I decided to put it back on and alrady today my boiler shut off with same error. My schedule was set to only heat my office to 21C and bathroom to 16C. Bathroom was already at 16C from the morning, and my office reached the 21C around 9.00am and just an hour later the boiler crashed. So to me it seems like all rooms have reached their temperature goal, but the boiler is instructed to keep heating? And it then crashes with an error because the very warm water is short circuited because tado closed all valves.
What can I do about this? I would really like to be able to heat a single room, such as my office, or my bathroom - without the need of having one radiator in the bedroom fully open.
Comments
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Sounds as though you need one radiator as a heat sink or else a bypass . . .0
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What's a bypass? I remember the technician mentioning that as well. Could you send me a linkt to such thing? 🙏
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Thanks! This is helpful.
However, If I understand the purpose of this device, that it is to ensure that water can circulate. So if the TRVs are all blocking, this one will open and let the water flow anyway.
I could try installing one, if it it helps, then the hypothesis about the returning water being too warm can be dismissed, and instead the problem would have been with the circulation. Does that sound likely?
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I think you should probably have a chat with a heating engineer, I'm only and amateur / tadoº user. Many central heating systems (especially smaller ones) require to have one radiator without TRVs which remains open at all times in order to disperse excess heat in overheating situations (e.g. all TRVs shut) and traditionally this is in the area where the room stat is situated so the pump and boiler stop when the stat is satisfied.
Many posters here have noticed that tadoº will sometimes run the boiler when there is only one "wavy line" showing on the app. and I believe in that state the TRVs are nearly shut.
I wonder whether that is what's causing your overheat and whether you should reinstate your heat sink radiator?
I also wonder whether reducing your pump speed might help so that the return water is cooler by the time it gets back to the boiler; but that is pure speculation on my part!
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Yes sounds like a good idea! Thanks for brainstorming with me here ;)
It would be nice if I could pick one of my valves to be "always open" in the app, instead og detaching the tado TRV from the radiator valve. This way, I could turn my bathroom radiator into the heatsink radiator, but still get stats about temperature and humidity
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Well you could set that valve to 25º, schedule it to be on 24 hours and set it to be independent so it is unable to call for heat and run the boiler . . .
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I'll give that a try, and see how everything behaves 👍
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Suggest that you a look at your boiler installation manual. It should say if an external bypass is required or of there is an internal bypass. Bit surprised that your heating engineer was not looking at that as one of the first checks?
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