En el hotel, la recepcionista nos cambió la habitación porque el radiador no funcionaba bien.

En el hotel means at the hotel or in the hotel.

Spanish uses en for location in many cases where English might say in, at, or sometimes even on, depending on context. Here it simply sets the scene: this happened at the hotel.

The article el is also normal. In Spanish, places and nouns often need an article where English might leave it out.

So:

• En el hotel = At the hotel
• not A el hotel, because a usually indicates movement toward a place, not being there

No. Recepcionista is a common-gender noun. That means the noun form stays the same, and the article tells you whether the person is male or female.

• la recepcionista = the female receptionist
• el recepcionista = the male receptionist

So in this sentence, la tells you the receptionist was a woman.

Nos means to us.

Literally, la recepcionista nos cambió la habitación is something like:

The receptionist changed the room for us
or
The receptionist changed our room

Here nos is an indirect object pronoun. It shows who was affected by the action.

A very natural way to understand it is:

• cambiar algo a alguien = to change something for someone

So:

• nos cambió la habitación = she changed the room for us / she switched us to a different room

This is a very common Spanish structure.

Cambió is the preterite, used for a completed action in the past.

The receptionist changing the room is a single finished event, so Spanish uses the preterite:

• cambió = she changed

If you said cambiaba, that would sound more like an ongoing or repeated action in the past, which does not fit this situation well.

So the contrast in the sentence is:

• nos cambió = the completed event
• no funcionaba bien = the background situation that was happening at the time

The accent mark shows both stress and distinguishes the form.

• cambió = he/she changed
• cambio = I change or change as a noun in some contexts

In the preterite, many -ar verbs have this pattern:

• cambié = I changed
• cambiaste = you changed
• cambió = he/she changed

So the accent is important.

Because it refers to a specific room: the room they were already staying in.

So:

• la habitación = the room
• una habitación = a room

In context, the meaning is not that the receptionist changed just any room, but their room. Spanish often uses the definite article where English might use a possessive:

• nos cambió la habitación
  literally: she changed the room for us
• natural English: she changed our room or she moved us to another room

Because Spanish often prefers an indirect object pronoun plus the noun, especially when talking about something that affects someone personally.

So:

• nos cambió la habitación = she changed the room for us
• cambió nuestra habitación would sound less natural in this context

This pattern is very common in Spanish:

• Me lavé las manos = I washed my hands
  literally: I washed myself the hands
• Le rompieron el móvil = They broke his/her phone
  literally: They broke the phone to him/her

Spanish often focuses on who is affected, not just possession.

Because porque here means because.

Spanish distinguishes these forms:

• porque = because
• por qué = why
• el porqué = the reason
• por que = less common combination in specific structures

In your sentence, it introduces the reason:

• porque el radiador no funcionaba bien = because the radiator wasn’t working properly

Funcionaba is the imperfect, which is used for an ongoing condition, description, or background situation in the past.

Here, the radiator’s bad performance is the reason/background for the room change. It was not a single event; it was a state or ongoing problem.

So:

• nos cambió la habitación = completed action
• el radiador no funcionaba bien = ongoing situation in the background

If you said no funcionó bien, that would suggest a more bounded event, like it failed at a specific moment or during a particular occasion.

It means it wasn’t working properly or it wasn’t working well.

• funcionar = to function / to work
• bien = well / properly

So no funcionaba bien does not necessarily mean it was completely broken. It suggests it was not working as it should.

For example, the radiator may have:

• produced very little heat
• worked irregularly
• made noise
• failed to heat the room properly

In Spain, radiador usually refers to a radiator/heater unit, especially part of a heating system.

So in a hotel room, el radiador would most naturally be the device used to heat the room.

This is very natural vocabulary in Spain. You might also hear broader terms like:

• la calefacción = the heating / heating system
• el radiador = the radiator itself

So this sentence is talking about the specific piece of equipment, not the whole heating system.

In real context, it normally means she switched us to a different room.

Although cambiar la habitación could theoretically be understood in other ways if there were no context, in a hotel situation the natural meaning is:

• the receptionist changed our room assignment
• she moved us to another room

That is how a native speaker would usually interpret it.

Yes, the sentence could be rearranged a bit, but the original is very natural.

Original: En el hotel, la recepcionista nos cambió la habitación porque el radiador no funcionaba bien.

You could also say:

• La recepcionista nos cambió la habitación en el hotel porque el radiador no funcionaba bien.
• Porque el radiador no funcionaba bien, la recepcionista nos cambió la habitación.

The original version puts En el hotel first to set the scene. That is very common and natural.

A very natural translation would be:

• At the hotel, the receptionist changed our room because the radiator wasn’t working properly.
• At the hotel, the receptionist moved us to another room because the radiator wasn’t working properly.

The second version is often the most idiomatic in English, because changed our room can sound a little ambiguous, while moved us to another room makes the situation clearer.