My wife and I have lived in our apartment for almost 2 months. We have been battling our office/management for over a month about our water heater. When we first moved in, we were not getting any hot water, had to keep pushing reset on the tanks thermostat to get it to heat up. Then a pipe broke and flooded our apartment. Maintenance tried 5 times to "fix" the old water heater. We have complained at least once a week to the management, and even called corporate office for our apartments, requesting the water heater be replaced. Its old, panels are falling off, and we still have to push reset button anytime we want hot water. I have been shocked once when pushing the button, which makes it a safety hazard also. The office keeps beating around the bush about it.
Landlord / Tenant Lawyer
AFTER you send the statutorily-compliant seven day notice to the owner/management, AND they don't respond within the seven days after receipt, THEN you can withhold rent.
If you are unsure about the statute or the form the letter should take, please see a local landlord tenant lawyer, esp. since this has been an ongoing issue and you were shocked by the device.