At Fawlty Towers, things start awry, and where they go from there is in the general direction of rank havoc. The domino theory is at work here, and the man pushing them over is also the one they tumble down on: Basil Fawlty, an insufferable and unforgivable cad one both suffers and forgives, because while most of us are frequently or occasionally at war with the world, for Basil hostilities never cease.

He is fighting one of the great losing battles ever fought on television, and for this reason and others, the dedicated and perhaps growing "Fawlty Towers" cult will welcome with open eyes the return of the BBC comedy program to Channel 26 starting tomorrow night at 10:30 and continuing for five more weeks after that. These are not new episodes--only a dozen were ever made--but reruns from 1975, yet the show has lost nothing in freshness, and Fawlty, as bombastically played by John Cleese, has achieved the status of crabby folk hero.

Fawlty and his wife Sybil (Prunella Scales), who has all the presence of mind in the family, operate a small English seaside hotel that is spiritually located on an outer periphery of darkest purgatory. The guests are an odd lot, but not as odd as the proprietor, an embattled and embittered old pedant embodied toweringly and endearingly by Cleese. The Monty Python alumnus cowrote the series with Connie Booth, who plays the minor but complementary role of Polly, part-time waitress at the dilapidated anti-establishment.

If television programs could gloat, this one would, for it returns after two different Hollywood attempts to duplicate it for American television failed miserably. The first, a total disaster, wasted and misapplied the talents of Harvey Korman. The second, the recent ABC flop "Amanda's," starring Beatrice Arthur, wasn't bad as American sitcoms go, but looked pale and tidy compared with the rarefied anarchy that Cleese and company whipped up so wittily.

Soon ABC will test-air yet another American sitcom patterned on a British sitcom, "Reggie," based on "The Fall and Rise of Reginald Perrin." It begins to appear there is a humor gap. One might almost think the British are intrinsically funnier than Americans are. Perhaps one factor contributing to this impression is that the BBC plays host to ideas, while American networks are only interested in "product," with originality low on the scale of priorities. PBS plays host to ideas, too, as long as they've already been played host to elsewhere, preferably in England.

In the episode that begins this latest round of reruns on Channel 26 (which at present has no plans to air the other six episodes), Fawlty's class prejudices are knocked for a loop when the seemingly highborn Lord Melbury (Michael Gwynn), a "peer of the realm" to whom Fawlty fawningly toadies from the moment he signs in as a guest, turns out to be a seedy confidence man embarked on a shady gem scam. The "Cockney git" who seemed to represent all the barbarism Fawlty abhors turns out to be a police officer on Melbury's tatty trail.

Cleese is particularly magnificent when enraged; he explodes like Daffy Duck in a cartoon. The only thing that keeps him from going terminally to pieces is his awareness of what joy this would bring to his enemies, who he sees as too numerous even to begin to count. The program is well-stocked with recurring nemeses, like the absolutely non-English speaking busboy Manuel (Andrew Sachs), and a few new ones are thrown in each week--guest nemeses. Cleese pushes his portrayal of Fawlty to wonderfully precarious brinks; it is masterful.

Cleese's portrayal of Fawlty also, as it happens, stands head and shoulders above Dabney Coleman's overpraised work as "Buffalo Bill" in the current comedy series on NBC. Buffalo Bill is a boor like Fawlty, but so much less interesting. Time and Newsweek have recently reported that the "Buffalo Bill" ratings have been good; in fact, they have been justifiably lousy, particularly for a first-run series competing against reruns.

Meanwhile, back at Fawlty Towers, not all the guests are sources of grief for Fawlty. He seems quite comfortable with The Major, a genial old duffer living out his last years by the sea. On occasion, "Fawlty Towers" stops being funny and becomes curiously charming, as when Fawlty is extolling Lord Melbury's alleged grandeur to The Major at the bar. "Ah," says Fawlty, "such--I don't know what."

"Je ne sais quoi?" ventures The Major.

"Exactly! Exactly!" Fawlty exclaims.

"Fawlty Towers" and Basil Fawlty still stand tall against whatever comes bashing their way, and there is more felicitous news to relieve the monotony of another monotonous television summer: "Monty Python's Flying Circus" returns to public TV on Saturdays beginning July 23. It's good to be able to laugh again at something that was meant to be funny.