Heat link broken, getting cold

[Elderberry]

My heat link, inherited with the house and quite old, is unreliable. The batteries seem to be loose and it can’t be fixed. 
a) Can I temporarily override the heat link if it isn’t working? I can only see explanations of how to override the thermostat via the heat link. And I’m getting cold. 
b) Can I buy a replacement heat link? I can’t find one anywhere without buying the whole thermostat. 

[george_t]

Hi @Elderberry. Can you tell me which Nest thermostat you have at your location? Here's a link to quickly identify which Nest model you have: https://goo.gle/2PBH1vk. 

[AlexD]

Hi, I wanted to check in. Do you need any further assistance? If so, make sure to let me know. 

[george_t]

It's been a while since this thread was last updated so I'll go ahead and lock this thread. If you're still experiencing problems, please feel free to start a new thread and we'll be happy to help.