Apenaŭ la administranto inspektis la kaldronon, la hejtado ĉesis.

Here apenaŭ means hardly, scarcely, or barely.

In this sentence, it creates the pattern “hardly had X happened, when Y happened.” So:

• Apenaŭ la administranto inspektis la kaldronon, la hejtado ĉesis.
• literally: Hardly the administrator inspected the boiler, the heating stopped.
• natural English: Hardly had the administrator inspected the boiler when the heating stopped.

So apenaŭ is not just about degree here; it also helps show that the second event happened almost immediately after the first.

Esperanto normally uses the simple past -is much more broadly than English uses the simple past.

So inspektis can cover:

• inspected
• had inspected

The time relationship is understood from context. Here, apenaŭ already tells you that one event happened just before the next one, so Esperanto does not need a special pluperfect form the way English often does.

That is why:

• Apenaŭ la administranto inspektis la kaldronon, la hejtado ĉesis.

is perfectly normal Esperanto, even though English often prefers:

• Hardly had the administrator inspected the boiler when the heating stopped.

Because it is the direct object of inspektis.

• la administranto = the administrator → the one doing the action
• inspektis = inspected
• la kaldronon = the boiler → the thing being inspected

In Esperanto, direct objects take -n, so:

• la kaldrono = the boiler
• la kaldronon = the boiler as a direct object

That is why kaldronon ends in -n.

Because la hejtado is the subject of the second clause, not a direct object.

In:

• la hejtado ĉesis

the meaning is:

• the heating stopped

Here la hejtado is the thing that stopped, so it is the subject. Subjects do not take -n.

Compare:

• La hejtado ĉesis. = The heating stopped.
• Li ĉesigis la hejtadon. = He stopped the heating.

In the second example, la hejtadon would take -n because it is now the object of ĉesigis.

Hejtado comes from hejti (to heat) plus -ad-, which often suggests an ongoing activity, process, or system-related action.

So hejtado can mean:

• heating as a process
• the heating system in everyday usage, depending on context

In this sentence, la hejtado ĉesis naturally means something like:

• the heating stopped
• the heating system stopped working

Hejto is possible in some contexts, but hejtado is very natural when talking about heating as an operating system or process.

The comma separates the two clauses:

1. Apenaŭ la administranto inspektis la kaldronon
2. la hejtado ĉesis

This is normal and helpful punctuation in Esperanto when one clause is followed by another, especially in a structure like apenaŭ ..., ..., where the second event follows immediately after the first.

So the comma helps show the transition:

• first event: the administrator inspected the boiler
• second event: the heating stopped

No extra word is required.

In English, we often say:

• Hardly had he inspected the boiler when the heating stopped.

Esperanto can express that same idea just with:

• Apenaŭ ..., ...

So there is no missing kiam here. The relationship between the two clauses is already clear from apenaŭ and the context.

That said, Esperanto does have other ways to express similar ideas, such as:

• Tuj kiam la administranto inspektis la kaldronon, la hejtado ĉesis.
  = As soon as the administrator inspected the boiler, the heating stopped.

But the sentence you were given is fully complete and natural as it stands.

It does not absolutely have to come first, but putting it first is the most natural choice here because it clearly sets up the hardly...when... relationship right away.

So:

• Apenaŭ la administranto inspektis la kaldronon, la hejtado ĉesis.

is a very natural order.

Esperanto word order is fairly flexible, but not every possible order sounds equally good. Since apenaŭ affects the whole first clause, sentence-initial position is especially clear and idiomatic here.

Ĉesis is the past tense of ĉesi, meaning:

• to stop
• to cease

So:

• la hejtado ĉesis = the heating stopped / the heating ceased

This verb is usually intransitive here, meaning the subject itself stops.

Compare:

• La hejtado ĉesis. = The heating stopped.
• Li ĉesigis la hejtadon. = He caused the heating to stop.

So ĉesi = stop / come to an end
and ĉesigi = stop something / cause something to stop

Because la means the.

So:

• administranto = an administrator / administrator
• la administranto = the administrator

Esperanto uses la as its definite article, and it does not change for gender, number, or case.

If the sentence is talking about a specific administrator already known in the context, la administranto is exactly what you would expect.

It can suggest that possibility, but grammatically it mainly expresses very close timing, not definite cause.

The sentence says that the heating stopped hardly had the administrator inspected the boiler. That strongly implies immediate succession, and in real context a reader might suspect some connection. But the grammar itself does not prove causation.

So the core meaning is:

• event 1: the administrator inspected the boiler
• almost immediately after that, event 2: the heating stopped

Any stronger idea of cause comes from context, not from the grammar alone.

In Esperanto, stress normally falls on the second-to-last syllable of each word.

So:

• Apenaŭ → a-pe-NAŬ
• administranto → ad-mi-nis-TRAN-to
• inspektis → in-SPEK-tis
• kaldronon → kal-DRO-non
• hejtado → hej-TA-do
• ĉesis → ĈE-sis

That regular stress pattern is one of the nice predictable features of Esperanto.