I’m afraid I don’t agree with Whale on this the contents policy is not relevant as the damaged items are fixtures of the lot and are covered by the strata policy not the contents policy.
This is what insurance is for accidental damage caused by some sort of failure (the hose). I know these items belong to the lot (not common property) but they are still covered by the Strata building policy (just like the home insurance of a normal freehold house).
Your problem though is going to be the excess and you are liable for this (as it’s lot property that is damaged) so it depends on whether the cost of the repairs is greater than the excess or not.
If the cost is greater than the excess the Strata insurance should pay the balance (but the Strata might pick up this cost if not excessive to keep the premium down by avoiding a claim).
It’s the EC who decide whether to claim (not the SM) or not and so unless the cost is large your only choice is to fight it at NCAT with every chance of winning IMHO unless you can convince the EC to pay or lodge a claim.