The hot water may be getting blocked somewhere in the pipes between the water heater and the fixtures.
The hot water heater is not working.
To rule out an undersized heater check to make sure the heater has 75 percent of its capacity as hot water.
Too little hot water.
When a standard tank style gas water heater stops producing hot water it means that the gas burner is no longer producing the flame necessary to heat the water.
You notice pools of water around the hot water tank.
You re running out of hot water.
A water heater not getting hot enough is usually to be blamed on the thermometer built into the unit.
The most obvious reason an electric heater doesn t work is that it s not receiving any power.
Check the circuit breakers in your fuse box.
This causes the dreaded hot water not working situation.
When the water s not hot enough the problem can be an undersized water heater crossed hot and cold connections or a faulty heating element or thermostat.
There is corrosion in the fittings.
If you have no hot water there are several possible reasons and you need to work through each of them methodically to eliminate each one and this will also depend on whether you have an electric or gas powered heater.
Reset the breaker or replace the fuse as necessary and restart your water heater.
Pilot light flame has blown out.
If the fuse has burnt out or the circuit breaker has tripped that directly controls the electricity for your heater it will not work.
If the breaker has tripped switch it off then switch it back on again.
Over time water contaminants can build up and harden in the bottom of your water heater reducing its ability to produce ample hot water.
You turn on the hot water tap and get cold water instead.
Depending on the cause of the problem the solution can be extremely simple or complex and expensive.
In the case of not enough hot water or hot water that is not hot enough it may be that you need to replace the heating element on your water heater.
Possible reasons for the malfunction include.
Not having enough hot water is a relatively minor issue.
Hot water heater not working.
First check the water heater s circuit breaker in the service panel to make sure it hasn t tripped.
Faulty thermostat the upper thermostat on an electric water heater actually controls both the upper and lower heating elements.
This tells the heater when to stop making water if it reaches a certain temperature.
You get a rotten egg smell in your water.
Of course the tp valve or pipe could still be warm if the water heater stopped working within the last 3 or 4 hours because the water inside would still be holding some heat.
The lower thermostat controls only the lower heating element so if it fails but the upper thermostat works the result is hot water not getting hot enough.