Xavi's place is very well located, in the historical center of Valencia, at a great price. The check in was easy and Olesya was very kind and helpful, she even came because the cilinder of the gas stove was empty.
We stayed in December and the house has no radiators. It's worth mentioning that you have only a gas stove and 2 electric heaters. Unfortunately, for us traveling with a toddler (and a 5-year-old) that was a problem, since we were so worried about them getting burnt.
The house has some other minor issues like that the bidet needs to be fixed, if you need hot water in the bidet you need to open the water also in the washbasin. However, the kitchen has everything you need, also salt oil sugar etc (that if you stay few days are always annoying to buy). We also had a crib and a highchair for our baby girl.
In conclusion if you don't envisage problems with the heating system as in our case, the house is a great solution for a nice stay in Valencia.