Tantum abest ut temperatura recta sit, ut balneator clipeum iterum moveat.

This is a set Latin expression. Tantum abest ut ... ut ... means something like:

• so far is it from being the case that ... that instead ...
• more naturally in English: far from ... , ... instead
• or not only is it not true that ...; rather ...

So in this sentence, Latin is saying:

• far from the temperature being right, the bath attendant moves the shield again

The first ut clause gives the thing that is not the case, and the second ut clause gives what actually happens instead.

Because this construction regularly uses two parts:

1. tantum abest ut + subjunctive
   = it is far from the case that ...

2. a second ut + subjunctive
   = that instead ... / that rather ...

So here:

• tantum abest ut temperatura recta sit
  = it is far from the case that the temperature is right

• ut balneator clipeum iterum moveat
  = that the bath attendant moves the shield again

To an English speaker, the second ut may feel odd, because English would usually switch to something like instead or rather rather than repeating that.

Sit is the present subjunctive of esse.

It is subjunctive because it stands inside the idiomatic construction tantum abest ut .... After this expression, Latin normally uses the subjunctive.

So temperatura recta sit does not mean a simple independent statement like the temperature is right. Instead, it is part of the pattern:

• tantum abest ut ...
• far from it being the case that ...

The subjunctive here is triggered by the construction, not because the idea is a wish or command.

For the same reason: it is in the second ut clause of the tantum abest ut ... ut ... construction.

So:

• ut temperatura recta sit
• ut balneator clipeum iterum moveat

Both clauses are subordinate and both take the subjunctive as part of this idiom.

Moveat is the present subjunctive of movere.

Here:

• temperatura = subject of sit
• recta = predicate adjective agreeing with temperatura
• sit = is / be

Both temperatura and recta are nominative singular feminine.

So the phrase works just like:

• puella laeta est = the girl is happy

In your sentence:

• temperatura recta sit = the temperature be right / the temperature is right
  but understood within the larger construction: far from the temperature being right

Because it agrees with temperatura, which is feminine singular.

Latin adjectives must agree with the nouns they describe in:

• gender
• number
• case

So:

• temperatura = feminine singular nominative
• recta = feminine singular nominative

This agreement shows that recta is describing temperatura.

Balneator means bath attendant, bath keeper, or someone connected with managing a bath.

In this sentence it is nominative singular, because it is the subject of moveat:

• balneator ... moveat = the bath attendant moves

So the basic grammar is:

• balneator = subject
• moveat = verb
• clipeum = direct object

Clipeum is accusative singular, because it is the direct object of moveat.

• movere = to move
• what does the bath attendant move?
  clipeum

So:

• balneator clipeum moveat = the bath attendant moves the shield

Iterum means again or a second time.

It modifies the verb moveat:

• moveat = moves
• iterum moveat = moves again

So it tells you that the bath attendant is adjusting the shield another time, which implies the first attempt did not make the temperature right.

Latin word order is much freer than English word order, because Latin uses endings to show grammatical relationships.

English depends heavily on word order:

• the bath attendant moves the shield

Latin can move words around more easily because the forms already show their roles:

• balneator = nominative subject
• clipeum = accusative object
• moveat = verb

Also, Latin often puts important or emphatic material earlier. Here the sentence begins with tantum abest, which signals the key idea right away: it is far from the case.

So the order is shaped more by style and emphasis than by strict subject-verb-object rules.

Yes. A very literal version would sound awkward in English. More natural translations might be:

• Far from the temperature being right, the bath attendant moves the shield again.
• The temperature is so far from right that the bath attendant moves the shield again.
• Not only is the temperature not right; the bath attendant even moves the shield again.

The first is probably the closest elegant English equivalent.

Here tantum is best understood adverbially: so much, to such a degree.

It modifies abest:

• abest = it is absent / it is far from
• tantum abest = it is so far from

So the phrase does not mean a great amount is absent in a literal sense. It functions idiomatically as part of tantum abest ut ...

Both are present subjunctive:

• sit from esse
• moveat from movere

The present subjunctive is normal here because the sentence is talking about a present situation:

• the temperature is not right now
• the bath attendant is moving the shield again now

If the main context were past, Latin could use imperfect subjunctives instead, depending on the sentence structure and sequence of tenses.

Yes: the whole pattern tantum abest ut ... ut ...

It is much easier to learn it as a single expression than to try to figure it out word by word every time.

A good learner’s note would be:

• tantum abest ut A, ut B
• far from A, B instead
• both clauses normally take the subjunctive

If you remember that pattern, this sentence becomes much easier to read.