Unable to change Up/Down dial Icon

[michelscholte]

I want to change the "default: ‘fas fa-calendar-alt’" icon in an alternative image. My code is:

blocks['temp_radiator_slaapkamer'] = {
type: 'dial',
subtype: 'updown',
idx: 3288,
width: 2,
temp: 3287,
title: 'Slaapkamer',
last_update: true,
graph: false,
image: 'icons8-smart-farm-68.png',
}

Instead of changing the icon is shows an extra icon on the top left of the dial block, see image below.
Also the "last_update" parameter don't show the last update.

Am I doing something wrong????