My Policy states

Contents Sum Insured £5,000
The following limits apply in addition to any amount stated in Your Policy document:-
£1,750 valuables in total
£2,000 any one valuable article except computer equipment
£4,000 computer equipment
£500 contents in garage(s)
£500 contents in outbuildings other than garage(s)

It's the bit in bold I'm confused about, if my policy is for £5000 insurance, yet only £1750 of valuables are covered, what's happening to the remaining £3250?

furniture, clothes etc?

Ah, was assuming they considered all contents as "valuables".

On a separate note – £5k sounds tiny… Are you sure it's enough?

valuables is jewlery (sp) watches, nazi gold in the basement etc.

who knows what you have. its for your valuables though. think about what you;d put in a safe. its for that.

try adding up the replacement value of everything you own

Blimey £5k I'd really consider shopping elsewhere.