Hey, We have bought a new house with an Danfoss Rx1 thermostat installed. We cannot get the thermostat and receiver to sync and turn the boiler on/off as programmed. Can someone let me know if this is wired up correctly and if not how to amend it. Also if this isn't the issue any advise would be appreciated.
Firstly, whoever has installed your thermostat receiver has used the earth core as a switched live without indicating at the ends of the cable. The diagram above is the correct wiring that should have been used. You should replace that cable with 4 core from the boiler. Have you tried new good quality Alkaline batteries? When you press the manual override button on the receiver, does the boiler fire? Have you tried repairing the thermostat to the receiver? This thread may be useful: https://community.screwfix.com/threads/danfoss-rx1-receiver-issues.215803/
Thanks, I was pretty sure that was an earth cable and causing part of the issue. I've tried the battery trick and reprogramming/syncing the thermostat several times. Opening it up became the last resort. If I press ch1 on the front then the boiler fires and manually switches on/off. Is installing a 4 core wire ppssoble for a home DIYer with a small amount of electrical knowledge?
You may then need a new thermostat. You can either purchase a similar one or replace with a smart/App. controlled one if you choose! Can you take a photo of the cable run and also how it connects into the boiler. You should first isolate the electrical supply to the boiler before removing the connection panel. There should be a switched fuse connection unit near to the boiler:
Awesome thanks, I isolated it with the switch and circuit breaker for the original photos, I maybe a little over cautious. Will attempt to look at this on the weekend and get back to you with further photos of the wore run inside the boiler. Thanks, Nick
Hey, from the inside of the boiler (and my assumption) have they utilised the earth wire as the control wire, without earthing the thermostat? Any info would be appreciated, thanks Nick
Very simple to replace that cable with a 4 core cable into the terminal block marked 96. I take it you have tried the suggestions in the other thread to re-pair the thermostat first?
Yeah I attempted the other fixes and attempted to repair the device etc. Currently the programme button will never turn on regardless of what I do and it won't pair/sync. Just a though, the earth wire has technically been wired as the control cable from the boiler. Regardless of me replacing this and wiring correctly, is it likely to work? Am considering just replacing the thermostat and the wiring after all this hassle and learning how to do it. Was Just thinking the earth wire is techbically doing what the new cable will, with no success. Also, thanks again for all your time and advice.
If the boiler fires when you press the manual override button on the receiver, then the issue isn't the cable. However, you should still replace the cable. You can use this or buy a shorter length at a local electrical wholesalers: https://www.screwfix.com/p/time-3094y-white-4-core-0-75mm-heat-resistant-cable-10m-coil/836pf
Awesome thanks, Have looked for some new wire, will also find a replacement thermostat or possibly smart one. Will replace the cable shortly, just a final question. The earth cable connects to the earthing port within the thermostat, where does the end within the boiler connect? Thanks again.
Connect the earth wire at the boiler end into the earth terminal in the block marked Mains to the left of the L terminal. You will have two wires in that terminal so make sure they are both secure. Only strip enough wire to go inside the terminal. There should be no loose strands visible like the L terminal in the block marked 96.