Boiler occasionally fires with no Tado LEDs on & all devices on App off
We have CH & HW managed by a Tado receiver and Individual Smart TRVs.
Both CH and HW are scheduled and work fine during scheduling, with the App showing that rads are heating and / or CH is on and the appropriate receiver LEDs illuminating.
However when the heating is off (like now in Summer) and outside of the HW heating schedule the boiler fires up and runs for several minutes at least once per day, possibly more. During this time neither the CH nor the HW LEDs come on on the receiver. None of the rads nor the HW show up as on on the App.
Any idea why the boiler is fired up and working when neither the CH nor HW is on and no LEDs are illuminating?
Best Answer
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Thanks @Tim_1_S
Straight away, I'm questioning why both HW NC and NO terminals have connections. It should be one or the other
Don't know the specifics of your system but normally it's an NO connection so the NC should be disconnected but that may not be the case for your setup
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Are you sure it’s not running the pump rather than igniting? I would be surprised if it’s anything to do with Tado, sounds more like a function of the boiler.1
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Hey johnnyp78. Thanks for responding.
The boiler is definitely igniting because the boiler LED comes on and you can hear it igniting and the pump working. Also the towel rail heats up which is linked to the HW immersion.
Isn't it the Tado receiver that instructs the boiler to fire up?
As a test we've just tried running HW through when the HW is scheduled to be off and, sure enough, the boiler has come on to heat the HW even though the App shows HW as off and there's no CH/HW LEDs illuminated on the receiver.
This suggests to me that the HW is permanently 'on' (other than being turned off by the stat when temperature is reached) and the HW stat is instructing the boiler directly & outside of Tado !?
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I don't think that tado controls the immersion heater for your hot water.....so I don't think that tado is firing up your boiler and this is the actions of your immersion heater Thermostat.0
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I would get the wiring checked. It sounds like your HW is permanently on regardless of the app setting or there's another path for a live feed to reach the HW circuit
When I bought my current house 13 years, I left HW on all the time on the programmer but after a few months realised that it was behaving like you've described i.e. regularly firing the boiler to top up the tank. This was using loads more gas compared with one or two scheduled periods each day.
Can you post pictures of the wireless receiver wiring?
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Thanks GrayDav4276.
The Tado is set up to control BOTH the CH and immersion for the HW. The HW has its own 'button' on the App and we can put the HW on with the App and / or the receiver and the HW LED illuminates.
That said, per my last comments it could be that the immersion Stat is firing up the boiler outside of the Tado receiver as you say.
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Hey davidlyall. Thanks for your comments. That does seem to be our situation. I'll get the electricians to take another look next time they are in. Photo of Tado receiver attached. It may be complicated by the fact we have an Actuator for CH / HW and another Honeywell motorised valve on the immersion coil return.
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Just to clarify, in an s plan system your HW would be NC rather than NO as I mentioned in my previous comment
Regardless, you'll need to confirm which yours is and only have that terminal connected1 -
Hey davidlyall. That's helpful thanks. Sounds like we've narrowed this problem down. We have both electricians and heating engineers coming back for phase 2 of our renovations and will discuss this thread with them.
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