Relay or Ebus Modulation?
Issue
The Tado was causing the boiler to enter Anti-Cycling mode. After speaking to Tado tech support, they have changed the Tado relay “to turn on once there is a heat request, and turn off once this heat request has been completely fulfilled”. Which seems to be working, but has caused greater peaks and troughs in the internal temperatures when compared to the Tado in being ‘relay modulating’ and I also feel this has removed some of the “smart” tech.
Tado also offered, if I wasn’t happy with the new configuration to “set the relay to only initiate on 50% of heat requests, which will reduce overshoots in temperature, however, it might cause bigger fluctuations, due to the later start”.
Kit
Wired Smart Thermostat Starter Kit V3+ - connected via Relay to…
Vaillant EcoTec Plus 831 Boiler (approx 12 years old)
7x Radiators (5 with non-smart TRVs, 2 Open Valve (Hall & Bathroom))
Potential Resolutions (that I’ve identified)
1. Stay as it is, relay requesting heat until fulfilled?
2. Change to the Tado alternative, relay initiate 50% of the requests? Could this still send the boiler into Anti-Cycling?
3. Revert back to ‘relay modulation’ and ask my central heating engineer to reduce the Anti-Cycling time limit on the boiler? Does Anti-Cycling matter, are the thermostat and boiler working against each other when in Anti-Cycling?
4. Re-wire to use Ebus - I believe, from what I’ve read, my boiler does support it, but at the same time, some people have had problems using the same boiler with ebus and have reverted to ‘relay modulation’. Is modulation a good idea for an oldish boiler, in terms of being always on, and wear and tear on old parts?
5. Something else?
I think I’ve read too much, with little knowledge and got myself a little confused! So I thought I’d ask the helpful and knowledgeable people here. What do you think would be the best route for me to take?
Thank you in advance for any assistance
Paul