The answer to 'shower no hot water' is that there are several common causes, including a malfunctioning water heater, a broken thermostat, or a problem with the water supply. Symptoms may include lukewarm or cold water coming from the shower, and the issue may affect the entire home or just the shower.
Some potential solutions include checking the water heater's temperature setting, inspecting the thermostat, and ensuring the water supply valve is fully open. If the issue is with the water heater, you may be able to reset it or replace the thermostat yourself. However, if the problem is more complex, such as a leak or a malfunctioning water heater, it's best to call a professional plumber to diagnose and repair the issue.