...
..and the
https://heatwallet.com/ has been down for more than 24h now.
The connection has timed out
The server at heatwallet.com is taking too long to respond....
Hm, for me it's up all the time.
As far as I remember, there were issues with the DNS host.
Try with the IP directly:
http://78.46.99.11 (just for test, no TLS)