H71 error no light

[Marked]

I have a 3rd Gen. thermostat that’s displaying an H71 error after working normally for well over a year, and thermostat not moved. The heat link has no light, and pressing/holding the button does nothing. The boiler has been power cycled, no change. The boiler functions normally otherwise and the heat link is receiving voltage as expected.

Another post on this site had the below questions asked so I will answer them:

Are there any lights on the Heat Link? Does the boiler activate when calling for heat by pressing the Heat Link's button to activate Manual Mode? No light, no activation.
Are you seeing any wiring report or error on the thermostat and/or the app? No errors
Have you had any recent power cuts in your area? If yes, has the power been restored? No power cuts, power is on and working.
Have you recently had service or maintenance on your electrical, plumbing, or heating system? No
If yes, how long was the power off for? (Be specific.)
Could you tell us please if you've checked on the breaker switch and fuse box? Yes, power is on.
Any blown fuse in there? Have you tried to turn the breaker switch off and on again? Any difference? N/A

Please advise.

thanks

Mark

[AnaM]

Hey @Marked,

Thank you for reaching out! All the information provided is useful so I'd like to create a case for you to help you sort this out. Can I use your email address showing on your Community profile to send you an email?

[DragosC]

Hi there. We're just checking in. Did you get a chance to check on the last message? Keep us posted. 
 

[AlexD]

Hey there, I haven't heard from you in a while so I'll be locking this thread. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community. Thanks, AlexD.