Wat die dreineerpomp betref, is dit herstelbaar.

It means as far as the drain pump is concerned, regarding the drain pump, or when it comes to the drain pump.

This is a common Afrikaans pattern:

wat + noun phrase + betref

So in your sentence:

wat die dreineerpomp betref = as for the drain pump

It introduces the topic before giving the main comment about it.

Not in the usual question sense.

Yes, wat often means what, as in a question. But in wat ... betref, it is part of a fixed expression and does not mean what? by itself.

So this sentence is not asking anything. It is making a statement.

A good way to understand it is:

• wat die dreineerpomp betref = as far as the drain pump is concerned

Because Afrikaans normally puts the finite verb in the second position in a main clause.

Here, the sentence starts with the topic phrase:

Wat die dreineerpomp betref

After that fronted phrase, the finite verb is comes next, and then the subject dit:

• Wat die dreineerpomp betref, is dit herstelbaar.

If you removed the fronted topic phrase, you would get the more basic word order:

• Dit is herstelbaar.

So the inversion happens because something else has been placed first.

Die means the here.

So die dreineerpomp means the drain pump.

It is used because the speaker is referring to a specific drain pump, not just any drain pump in general.

Compare:

• die dreineerpomp = the drain pump
• 'n dreineerpomp = a drain pump

Also, unlike English, Afrikaans uses die for both singular and plural definite nouns.

Yes. Afrikaans very often writes compound nouns as one word.

So:

• dreineer = to drain
• pomp = pump
• dreineerpomp = drain pump

This is very normal in Afrikaans. English sometimes writes similar combinations as two words, but Afrikaans usually joins them into a single compound noun.

Herstelbaar means repairable or capable of being repaired.

It is built from:

• herstel = repair / restore
• -baar = a suffix meaning something like -able

So:

• herstelbaar = repairable

This suffix is very useful in Afrikaans. It often works much like English -able.

For example:

• leesbaar = readable
• eetbaar = edible
• sigbaar = visible

Because dit is the normal Afrikaans word for it.

Afrikaans does not use grammatical gender the way some other languages do. For objects like machines or parts, dit is completely normal.

In this sentence, dit refers back to die dreineerpomp.

So:

• die dreineerpomp = the drain pump
• dit = it

It is an adjective.

In is dit herstelbaar, the word herstelbaar describes the condition or quality of dit:

• dit is herstelbaar = it is repairable

So this is not a passive verb form like is repaired. It is more like English repairable, which is also an adjective.

If you wanted a more verbal idea, Afrikaans could also say:

• Dit kan herstel word = It can be repaired

That means almost the same thing, but the structure is different.

Yes. A simpler, more direct version would be:

Die dreineerpomp is herstelbaar.

That means the same basic thing: The drain pump is repairable.

The original sentence:

Wat die dreineerpomp betref, is dit herstelbaar.

sounds a bit more like:

• As for the drain pump, it is repairable
• Regarding the drain pump, it is repairable

So the original version gives extra topic emphasis, while the simpler version is more straightforward.