My oil fired hot water heater provides only sporadic hot water. For example, when I am home alone it takes 2 minutes to get luke warm water in the shower, then it is only warm for a few minutes, then colder, then warmer, then I get about 2 minutes pretty hot water, then luke warm for a few more, then cold, then hot etc.

This issue may be caused by several factors, including a malfunctioning or improperly sized water heater, clogged pipes, or a malfunctioning thermostatic mixing valve. Here are some steps you can take to troubleshoot the issue:

1. Check the size of your water heater: If your water heater is too small for your home's needs, it may not be able to supply enough hot water to all areas of your home. Consider upgrading to a larger water heater.
2. Check for clogged pipes: If your hot water pipes are clogged with mineral buildup or debris, water flow may be restricted, causing reduced hot water supply. Have a plumber inspect your pipes and clean them if necessary.
3. Check the thermostatic mixing valve: If your home is equipped with a thermostatic mixing valve, it may be malfunctioning and causing the issue. Have a plumber inspect and replace the valve if necessary.
4. Check for leaks: If there are any leaks in your hot water pipes, the water pressure may be reduced, causing reduced hot water supply. Have a plumber inspect your pipes and repair any leaks.
5. Adjust the temperature settings: Make sure the temperature settings on your water heater are properly set. If the temperature is set too low, you may not be getting enough hot water.

If these steps do not resolve the issue, it is recommended to contact a licensed plumber to inspect and repair your hot water system.

If the vent has been running for 3 days, is there fire in the hole? I suspect there is a lot more to this story. If there is fire in the hole, turn off gas and call someone before you get killed. Seriously.

sounds like you have the heater set on its highest setting and its tripping the thermal protector. If that trips the water inside has to cool way down before it resets itself. Try setting the temp lower.
One more thing this time of year the water comming into the home is a lot colder this time of year and that makes the heater work harder and takes longer to heat the water. 40 degree water takes longer to heat than 65 degree water in the summer. This also means that it dont take much water cool the water in the water heater faster to luke warn.
If this is new home with a new water hater you might think about going tankless,then you have endless hot water and save money at the same time.

Why is the home inspector removing cover on a water heater?
He might be going overboard to provide good inspection, but my experience says never mess with something old or it will break next day and you get blamed.
He could have made visual inspection for leaking, and checked if water was hot by opening drain valve and TP valve ... but he might cause a drip doing that.
He shouldn't open any appliance.
Did the inspector cause the problem? Maybe yes, or maybe not.
Maybe he helped solve a bigger problem that was looming but hadn't happened yet, and it forced you to get a new heater which you probably feel more comfortable with.
http://waterheatertimer.org/How-to-maintain-water-heater.html

Call the manufacturer about warranty coverage. manufacturer appears on label on side of tank.
http://waterheatertimer.org/Water-heater-manufacturers.html
Troubleshoot resources:
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Water heater is heating water but only luke warm water arrives at faucet.
Open TP valve and confirm that hot water is available.
If water at TP valve is hot, then problem might be plumbing-related, for example crossover.
http://waterheatertimer.org/Crossover.html

Hi,

If your electric hot water heater is not working...check out this tip about electric hot water heater problems

Electric Water Heater not Working

heatman101

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Sounds like hard water. Service the water valve. Parts are available from your local Bosch Service Provider (Contact Bosch if you don't know who the service provider is).

it is located on the thermostat. Take the cover off the side and you will see a little red button in the side of the themostat.

Hello .. when an electric water heater only gets warm, it is usually the thermostats. I would replace the thermostats, make notes where the wires are connected .. make sure after replacing that the back of the thermostat is flat against the metal of the tank.

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