Homeowner's insurance covers the cost of fixing many of the problems that can arise in an aging home. It may cover water damage caused by a leaky roof, damage to interior pipes that burst due to age or poor insulation, and fire damage caused by faulty electrical wiring. While every policy is different, most homeowner's insurance policies pay for some costs associated with faulty interior plumbing and electrical wiring. Depending upon the policy, problems with exterior plumbing and wiring may or may not be covered.
If the broken sewer line in question is an underground pipe that connects to the main municipal line in your neighborhood, your insurance company will want to know where exactly the break occurred. It is unlikely to cover a break that occurs outside of the "footprint" of your home's foundation under any circumstances. If the break occurred within the home's foundation, it may be covered.
In general, homeowner's insurance covers issues that can be traced to non-negligent damages. This typically excludes the effects of normal aging and "wear and tear." Before approving or denying your claim, your claims adjuster will want to know the rough age of the pipe. He or she will also examine the length of the pipe to check for other signs of aging like rust or thinning. He or she may also look for loose joints and other signs of faulty workmanship. Finally, your claims adjuster will look for signs of weathering caused by poor or missing insulation.
If your claims adjuster determines that the pipe has broken due to age or weathering, you may face an uphill battle to secure coverage for its replacement. Your insurer will likely deny your claim on the grounds that you should have performed regular maintenance on the pipe or replaced it before it broke. If you report the break as an ongoing problem, the likelihood of this response will increase further. In fact, it may not even be worth your time to report such a recurring issue.
On the other hand, your homeowner's insurance policy is likely to cover the costs of replacing a sewer line that bursts due to shoddy workmanship or poor insulation. If the break causes water damage in your basement or elsewhere, your policy may cover cleanup-related costs as well. If the break occurs during the winter and can be attributed to freezing, this outcome is even likelier to occur.