I have an Orion 512 controlling the hot water times through an RSX512 module and I have no hot water. What do I do?

Modified on Thu, 24 Nov 2022 at 02:42 PM

If you have recently edited the timer settings on the Orion 512 and the hot water has then stopped working – see article “None of my Nobo Orion 512 controlled panel heaters are working – they are all cold and refuse to heat up. What should I check?” as this describes checking the system is not in a frost or suspended mode.


If you have not recently edited the timer and the hot water has stopped working, try sending an override for the hot water. Press the Zone button until your Hot Water Zone number is on the Orion 512. Press the Red “Constant Program Override” button. If hot water is not produced within a couple of hours, you need to call out a local electrician to conduct further tests. They will need to check that your hot water element & thermostat are working OK. If they are both OK, then it is likely that the RSX512 module that switches power to the immersion has failed.


As RSX512 has been out of production >10 years now, the electrician should replace it with a standard hot water immersion timer. These are available at most electrical wholesalers.

Was this article helpful?

That’s Great!

Thank you for your feedback

Sorry! We couldn't be helpful

Thank you for your feedback

Let us know how can we improve this article!

Select atleast one of the reasons
CAPTCHA verification is required.

Feedback sent

We appreciate your effort and will try to fix the article