Proprietarul repară centrala termică și caloriferul.

Because Romanian usually puts the definite article at the end of the noun instead of using a separate word like the.

• proprietar = owner / a owner
• proprietarul = the owner

The ending -ul is the masculine/neuter singular definite article here.

Repară is the 3rd person singular present tense of a repara (to repair).

So it matches proprietarul (the owner), which is singular:

• eu repar = I repair
• tu repari = you repair
• el/ea repară = he/she repairs

In this sentence, proprietarul repară means the owner repairs / is repairing, depending on context.

Romanian often leaves out subject pronouns when they are not needed, because the verb ending already shows who is doing the action.

So instead of saying:

• Proprietarul el repară...

Romanian normally just says:

• Proprietarul repară...

Even without el, the meaning is clear.

In Romanian, adjectives often come after the noun.

So:

• centrală = central unit / boiler unit
• termică = thermal / heating-related

Together, centrala termică is the normal Romanian order: noun first, adjective second.

This is very common:

• casa mare = the big house
• mașina roșie = the red car

In Romanian, the definite article is usually attached to the noun, not repeated on the adjective.

So:

• centrală termică = a heating boiler / a thermal unit
• centrala termică = the heating boiler

The adjective termică still agrees with the noun in gender, number, and case, but it does not take its own separate definite article here.

For the same reason as proprietarul: Romanian uses an attached definite article.

• calorifer = radiator / a radiator
• caloriferul = the radiator

Here caloriferul is masculine singular, so it takes -ul.

Because the sentence is talking about specific, known things: the heating boiler and the radiator.

Romanian, like English, uses definiteness when the speaker means particular items rather than any boiler or any radiator.

If the meaning were more general or indefinite, you might see:

• o centrală termică = a heating boiler
• un calorifer = a radiator

But in your sentence, both are specific, so both are definite.

They are direct objects, so they are in the accusative function.

In Romanian, for many nouns, the accusative form looks the same as the nominative. So nothing special has to appear here beyond the normal definite forms.

The structure is:

• Proprietarul = subject
• repară = verb
• centrala termică și caloriferul = direct objects

Because Romanian, like English, can use one verb with two coordinated objects.

So:

• repară centrala termică și caloriferul

means the owner repairs both things.

The word și means and, linking the two objects together.

Ș (S with a comma below) is pronounced like sh in shoe.

So:

• și = pronounced roughly sh' or shee depending on the context and speed of speech

Romanian has a few letters with diacritics, and they matter:

• ș = sh
• ț = ts
• ă, â, î also have special sounds

So și is not the same as plain si.

You would remove the definite endings and use the indefinite articles:

• Proprietarul repară o centrală termică și un calorifer.

That means he is repairing a heating boiler and a radiator, not necessarily specific ones already known in the conversation.

So compare:

• centrala termică / caloriferul = the heating boiler / the radiator
• o centrală termică / un calorifer = a heating boiler / a radiator

The basic order here is the most natural one:

• Subject + Verb + Object
• Proprietarul repară centrala termică și caloriferul.

But Romanian word order is somewhat flexible, especially for emphasis. For example, you might move an object earlier in the sentence in special contexts. Still, for a learner, this standard order is the safest and most natural choice.

So this sentence is a very normal everyday structure.