Water Heater FAQ

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Welcome to our Water Heater FAQ page

If you are having a problem with your water heater here’s where you can read about the most common issues water heaters have and answers to the problems our customers ask us most often.

Water heaters generally have three main problems:

They leak

They do not produce any hot water

They produce luke warm water

Leaking Water Heaters

A leaking water heater can be caused by a crack, pinhole, or fracture in the internal water tank. Typically you will not see any problem with the water heater, it may even look almost new, but you will see water coming out from the bottom of the unit or mysteriously pooling around the bottom of the tank. When this type of leak occurs it usually means that the water heater has failed and the whole unit will require replacement. If your water heater is 8 years of age or older and you notice a leak, this is mostly likely the case.

A water heater can also leak from a connection in the tank to the plumbing or a plumbing part connected to the tank can leak. If you notice water on top of the tank or water pooling up on the top of the tank, this is a sign that either the connection to the tank has a problem. The plumbing fitting inside the tank may be faulty or the pipe connected to the fitting in the tank has gone bad.  Occasionally if the water heater has a thermal expansion bottle connected on the cold side piping above the water heater the thermal expansion bottle can leak and water will drip down onto the water heater and it can appear that the pipe or the water heater is leaking. In these situations a repair can usually be done, by replacing the fitting, the flex line or the expansion bottle.  If the leak has gone unnoticed for some length of time and the top of the tank has begun to rust (as seen in the photo below) unfortunately the entire water heater may need to be replaced.

A water heater can also develop a leak from the drain valve near the bottom of the water heater. This is the small spout where the water heater can be drained for maintenance purposes. This part can also be easily replaced as long as the water heater is not too old.

Finally a water heater can leak from from the pressure & temperature valve also known as the p/t valve, t/p valve or overflow pipe. The p/t valve is connected to either the top of side of the water heater and should have a pipe connected to the valve that runs down along the heater and ends about 7 inches from the ground. The p/t overflow pipe can also run under the house or through a wall to the exterior of the home.

This safety valve is designed to relieve excess pressure or temperature that builds up in the water heater. Remember water expands when it is heated and when there is high pressure and extreme heat water heaters can be dangerous. This valve will open and release water and close when the excess pressure has dissipated. The p/t valve can fail and require replacement, but if your p/t valve leaks it is usually a sign that there is another issue going on in the system. Either way we recommend having a service call preformed to test the incoming pressure to the home, check for thermal expansion and at the very least replace the valve if it is deemed faulty.    

No Hot Water

The worst thing is waking up to take a shower and learning you have no hot water. Most often this is a sign that something is wrong with the water heater, usually the pilot light has gone out and the water heater can’t “turn” itself on to heat. The best option is this case is simply that the pilot needs to be re-lite. However, this is not usually the case, but we always recommend trying to re-light the pilot first and see what happens.

If the pilot does not light and you get no flame at all, you may want to check to ensure that gas service to the home has not been interrupted. If the pilot light will not hold or lights but goes out after a few seconds it’s lite, this usually means the thermo-couple or thermo-pile has failed. Older water heaters had a standard universal thermo-couple that was a very easy part to replace. If your water heater was manufactured prior to 2003, a thermo-couple replacement is an easy repair.

However, with most newer water heaters, this is not the case. When the 2003 FVIR Federal Regulations for water heaters went into effect, water heater manufacturers created new designs to comply with the standards. These FVIR water heaters are much safer, but they are designed very differently than their previous models. The FVIR tanks have closed combustion chambers and specialty parts. This makes water heaters harder to repair. Each manufacturer designed there own style of unit and most water heater now have special parts that do not interchange with other brands. Replacing a thermo-couple is not as easy at it used to be and can be more costly.

Another issue with the pilot light is connected to the gas control valve or what some people call the thermostat. If you light your pilot and it works, but then it goes out after the tank has reheated itself it could be a thermostat problem. In this case the entire gas control valve will need to be replaced.

Luke Warm Water

A common water heater FAQ / complaint our customers call about is luke warm water. It’s not really hot, it’s not cold it’s just blah. There are a variety of reasons for luke warm water, some are in fact related to the water heater, but more often it is due to problems in the plumbing. A great starting point in troubleshooting luke warm water is to test the hot water only in multiple faucets in the home, try to test at least two different fixtures other than the one where you notice the luke warm water.

For example, if you notice your shower water is luke warm, make sure you also test the hot water faucet in the kitchen and the sink in the bathroom. Luke warm water in the shower is commonly attributed to a shower valve going bad. Most showers have a mixing valve that allows a certain amount of hot water and a certain amount of cold water to mix and go out the shower head. When this valve fails it can not mix the water correctly and you end up with luke warm water. If you have hot water in the kitchen or bath room sink, but the shower is luke warm, you probably have a bad shower valve.

Similarly, if you have luke warm water in a bathroom sink, but hot water in the kitchen this is a sign that the problem is related to the plumbing in the bathroom versus the actual water heater.

On the other hand if you have luke warm water coming out of all your fixtures, try turning the water heater up a bit and see if that helps. If you notice the temperature does increase it means the water heater is working, but the gas control valve aka thermostat could be beginning to fail.

Luke warm water problems are a little harder to diagnose than simply having no hot water. In certain homes there are multiple mixing valves and sometimes plumbing cross over can occur or a broken pipe in the slab can contribute to having luke warm water throughout the home. Once you do a little troubleshooting and your pretty sure the problem is the water heater you may need to replace the gas control valve.

The thermostat or gas control valve is the part most often connected to luke warm water problems. It can easily be replaced on most water heaters. If your water heater is over 10 years old or has a lot of scale build up, the best bet is to replace the entire tank. Gas control valves are not cheap and water heaters generally last 10-12 years.

If you still have questions about a problem with your water heater check out our main websites’ detailed water heater FAQ page. We answer over 30 water heater related questions and really get into some of the old-ball things that can go wrong with a water heater. You can also contact us at (510) 839-0414 24 hours a day, 7 days a week to speak with a water heater expert and get answers specific to the problem you are having.