I have been calling a lot. The problem was determined to be a bad radiator thermostat. Then I provided a lot of additional information, which the agent Elie asked for. In the end, they said that the radiator thermostat was too old and we could not replace it. Although, as the advertisement says, Wiser radiator thermostats last 10-15 years. So why they ask to send photos and all other information, if they know that they change radiator thermostats, only that they have only been used a little? I felt that there was some kind of game with me and this left me with a very unpleasant impression of Wiser customer service.