A hot water heater can leak from the top, bottom or through the inlets and outlets. There can be simultaneous leaks from different parts but it is indeed rare. At a time, you should have a leak only at one place. That is unless you have a very old water heater which is in a very poor state and is about to go kaput. Many people think that a leak is a sign of irreparable damage and that one must replace the water heater. You don’t need to buy a new water heater, not yet. Only if the leak is beyond repair and is actually due to some structural damage to the heater or the inner chamber then you need to think of a replacement. Else, all leaks are reparable.
Let us first explore the reasons or causes of hot water heater leaking from top and then we shall talk about the remedies you can opt for.
The First Steps Before Inspection
Cut off the power supply. You don’t want a functioning water heater, heating the water inside and increasing the pressure when you try to look for the leak. Do not turn off the water supply though because then the leak may not become obvious. Ensure that the thermostat is also turned off. If the water inside is hot already, let it cool down. Allow some hot water to flow out if you want. However, this is not always ideal as if the heat and increased pressure has to do anything with the leak then letting the hot water flow out of the faucet, shower or into the tub will make the leak less obvious.
You should clean the floor below the water heater so you can spot new droplets or pooling water as you observe the leak and look for its source. Having a wet floor will make matters complicated. Remember to turn off the water supply or the inlet of the cold water into the heater the moment you find the leak and are certain. This will reduce the pressure, reduce the leak and you will have a more contained scenario to deal with.
Causes and Remedies of Hot Water Heater Leaking From Top
Look for the water inlet valve. Usually, when hot water leaks from the top of a heater, it is due to a worn-out inlet valve. It is possible that the outlet pipe has a leak or the inlet valve is facilitating the leak. The valve may be partly or completely damaged. It is normal to use over a period of time that you can blame. The quality of material used by the manufacturer will also play a role. This is not a big problem because you can just replace the inlet valve without much fuss. You may also find the valve to be absolutely fine and usable but it is the part of the heater that seems to be leaking. This could be due to a loosened nut. Tightening the nut will be enough. If the nut is damaged or doesn’t tighten enough, get a new one.
The inlet pipe may also be the culprit here. If the inlet pipe is loose or is not connected properly, then water can leak through the tiny gaps. It is very common to have pressure fluctuations of water causing such problems. As the temperature of the water supplied by the city or the local civic body varies from one season to another, the pressure of the water also varies. Where your overhead tank is, what kind of plumbing network the water is routed through until it gets to the tank and several such structural and installation factors will influence the pressure as well. Check the inlet pipe and tighten it if it appears to be loose or not impeccably sealed. You may have to consider replacing this pipe if it is beyond sealing or tightening.
Every water heater has a temperature and pressure relief valve. This valve may leak when the temperature or the pressure of the water inside the heater increases. Now, temperature and pressure are both proportional here since heated water would expand and take up more space, thus increasing the pressure that the relief valve is supposed to endure. In either or both scenarios, whether the pressure increase is regardless of temperature or the thermostat setting is higher than necessary thus increasing both metrics, the relief valve could fail and that may cause the leak.
Hot water heaters, especially those powered by gas, tend to leak from the top when rainwater gets accumulated on the top of the tank. Storms and strong winds can divert rainwater down flue vent pipes and the water pooling is facilitated. Condensation too can be blamed at times. You should find out if the water heater has enough capacity to heat as much water as you are compelling it to deliver.