New boiler issue

Maintenance

Hi everyone. My tenant has been fussy about her bills for gas and the temperature of the hot water so I am aware she does over react and therefore want to consider my response to her email this evening. She has emailed: "We have some prob whit central heating :-(i don 't now what is happend but I not working properly...! Thx". This is a one year old boiler (Worcester) and I just had it serviced a couple of months ago. I would like to know more information before I agree to send out a plumber but also I would like to ascertain, if it is damaged what caused that. I know it is a good boiler. They have the heating on full blast ALL the time. Everytime I have visited I have had to take my coat off immediately on entering. Can a boiler be overworked does anyone know. Any advice as I am trying to pre-empt this cautiously. Last time I had a tap head replaced the tenant demanded a mixer tap as she says the water temperature would scald her hands even though it is a safe temperature for example.

many thanks in advance to you experts.