Help Viessmann vitodens 100

[Boiler87]

Hello everyone first time on this forum I'm seeking some advice, recently I have noticed that my Boiler never drops down below 35c even after hours and hours of no use whereas before it would always drop down to between 19-24c after no use say overnight etc, my question is A is 35c degree anything to worry about? and B how can I lower the value back to around 19-24c when it's not been used for a few hours?
Please note I'm talking about idle temperature the boiler drops down to when it's not been used for a few hours I'll try attach a picture.

Edit Additional information my Boiler was serviced a few months ago not sure if it's related.
Thank you very much in advance.

 

[JonathanM]

How do you turn the boiler off, when it's not in use? Do you use some sort of thermostat, or programmer?

 

[Boiler87]

Hi we don't turn the actual boiler off to say, we have a portable thermostat that sits in the living room it turns the heating on when the room temperature reaches a certain low and off again when room temperature is reached.

The Boiler is a Combi Boiler

I'm just wondering if during the last service maybe the engineer set something to prevent the boiler going below 35c?

Thanks

 

[JonathanM]

EDIT: Deleted as confusing

 

[JonathanM]

Does the temperature on the display go up and down normally when the boiler is on?

 

[Boiler87]

It goes up as Normal and decreases once it's off but where's before it would eventually drop to around 20c with no more use it now hovers at 35c.
It may just be a normal setting that was changed during a service or not changed back. Is 35c a safe temperature for the boiler to be at idle or is it a bit high and putting a bit too much stress on it long term?
I think I am going to contact the company who did the service last.

Sorry if my information isn't great but I'm not particularly savvy when it comes to boilers etc.