Worcester A21 Error Code - What is it and How to fix!

[@Survivethejive]

I unpaired them myself by messing with the pairing and now a21 and a28 show but can’t get back to pairing menu as neither responds

[@iheat]

Have you got in touch with Worcester about this issue, cheers

[@MackMateCom]

Thanks buddy issue sorted thanks for uploading the video much appreciated 👍🏴󠁧󠁢󠁳󠁣󠁴󠁿

[@iheat]

Awesome to hear!!

[@HilaryBurtMusic]

Thank you! Didn’t even know we needed to change the batteries! We now have heat!

[@iheat]

Awesome stuff! Very happy to hear this!

[@MuksC]

Hoping you can help me. Moved into a new place with a WB boiler and Comfort RF II thermostat. I can make the heating come on by toggling the heat control button between ON/OFF/AUTO but can't program it because the right hand menu button doesnt work and this is the button that gets you into the settings menu. I bought a 2nd hand identical thermostat with the intention to pair it to the boiler and then be able to set up programs. In all the videos I've seen they instruct you to unpair the boiler first and then unpair the thermostat and then press the override button on the boiler for a number of seconds and then start the pairing process on the thermostat. If successfully paired, the thermostat should display a 1. But only 0 is showing on mine (meaning not paired). And now because I had to hold down the override button on the boiler, it's now unpaired from its original thermostat, leaving me with neither thermostat paired to the boiler, and I can't even re-pair the old broken thermostat because the right hand menu button doesn't work. Have you any advice on how to pair the new thermostat please?

[@iheat]

With this I suggest a few things, first I'd contact Worcester Support to see if they have a sneaky way of pairing up when the same circumstance happens as your facing. If no progress on that end I would look to buy a new thermostat such as the EPH Combi 4 or Honeywell T3R that we provide here at iHeat as they are wildly easier to control and face less problems! The second hand thermostat you have bought also sounds faulty so I'd try get money back on that to go towards a new thermostat.