Hot Water Not Working but Cold Is [How to Fix]

It can be annoying and excruciating to turn on your shower and suddenly find out that there’s no hot water. If your hot water is not working, but cold is, what could be the reason?

The most common reason is a busted upper thermostat that requires replacement. However, even if the thermostat is working properly, a lack of regular maintenance can cause the water heater to malfunction. One such issue is years’ worth of sedimentary buildup. To fix this, flush the water heater. 

Read on to learn more about why the hot water is not working, but cold is, and how to fix it.

Why Is the Hot Water Not Working but Cold Is?

Hot Water Not Working but Cold Is

Typically, when you turn on your shower or kitchen faucet, you expect hot water to come out. However, if only shockingly cold water comes out, there might be a problem.

Many things could cause this problem. Some of these problems can be quite dangerous. However, before you think of the worst-case scenario, you can also find other non-dangerous reasons behind it. Among the most common reasons why your water heater no longer works properly are:

1. Leaking Water Tank

For your water heater to work, there must be water in the tank. If the tank does not have water, it probably means that the tank is leaking severely. Check all the plumbing connecting the water heater to the water main. Also, check the pipes, connectors, and valves for leaks. If you cannot find leaks in the plumbing, the problem must lie in the storage tank.

2. Water Heater Is Not Getting Gas

If there are no leaks and the water heater gets power, the problem might be with the gas supply. This is true if you have a gas-powered heater. You or someone else may have accidentally turned the gas valve off or forgot to turn it on again. If that’s the case, just turning the gas back on will remedy the problem.

3. No Pilot Light

If you peek under the heater and you don’t see a small flame, it means the pilot light is off. The only fix, therefore, is to re-light it. However, most modern water heaters no longer use a pilot light. They use electric igniters or glow plugs. If that’s the case, you’ll need to contact a professional HVAC technician to fix it.

How to Re-light the Pilot?

If your heater comes with a pilot light, check the user’s manual for instructions on re-lighting it. Now, if you have a rather old heater and you no longer have the manual, follow these steps for re-lighting:

  • Switch the regulator. Wait for around five minutes so the remaining gas could dissipate.
  • Switch the regulator to the “pilot” setting.
  • Utilize the water heater’s self-ignite function, press and hold the ignition switch for a minute or so. Afterward, switch the regulator to the “on” position.

Meanwhile, you will need a long-stemmed kitchen lighter if you need to light the pilot by hand. Open the gas inlet and try to light the pilot once again using the lighter.

If the pilot light still doesn’t turn on, the heater’s thermocouple might be faulty. Call your gas utility provider and tell them about your problem. They would usually fix that kind of problem for free.

4. Gas Leak

Not only is leaking gas from your water heater inconvenient, but it is also dangerous. Inspect the water heater. If you get a strong whiff of natural gas, you should get your family out of the house. You should then call the gas company to send a technician immediately.

However, the gas company technician will not be focusing on fixing your water heater. They will be looking for the cause of the gas leak. If they discover that the leak is within your water heater, they will disconnect it from the gas main. After that, they will shut the supply off. It will be up to you to get your water heater repaired.

5. Electric Water Heater Malfunction

One reason why your electric water heater does not produce hot water is a tripped circuit breaker. Check your fuse box if the breaker for the water heater did trip and just reset the breaker.

Hopefully, after an hour, you will once again have hot water. If the water heater continues to trip the breaker, you may need to get the help of a qualified electrician.

6. Faulty Water Heater Thermostat

For the water heater to produce hot water as efficiently as possible, set the thermostat between 122-140°F. If you’re not getting any or enough hot water, check the upper thermostat.

A broken thermostat may mean getting a technician to replace it. If the thermostat is working fine, then there might be too much sediment buildup in the tank. This buildup may be the one that prevents it from working as intended. To fix this problem, flush the entire system and restart the water heater.

7. Too Small Storage Tank

If you have a big family, the tank may not be that big to keep up with the demand. In addition to not being as energy-efficient as it could be, you will lose hot water whenever you need it. There’s nothing else you can do about this issue other than upgrade to a bigger water heater.

8. Cold Weather

The outside temperature can also affect the efficiency of your water heater. This is especially true if there is not sufficient insulation. If you live in an area where cold snaps during winter are normal, it can affect your water heater function.

Again, hot water not working, but cold is – what causes this issue? If you have good water flow and the cold water is working, then your piping is fine. Most likely, the problem is in your water heater or the mixing valve.

When Do You Need to Replace Your Water Heater?

pilot light on but no hot water

Sometimes, it’s more cost-effective to replace the water heater instead of finding out why it malfunctions. However, it is better to consult your plumber or technician if it is still worthwhile to keep your water heater.

Here are some of the reasons why you should consider replacing your water heater:

1. Hot Water Is Always Running Out

Your water heater may have been enough for you and your spouse before. However, you might not keep up with the additional demand when you have a couple of children. If that’s the case, you will need to upgrade to a newer water heater with a bigger storage capacity.

2. Appliance’s Age

How old is the water heater in your home? Top brand water heaters can last anywhere between 15 to 20 years. After that, they will start to deteriorate. If your heating system is coming up in years, it’s better to replace it with a newer, more efficient model.

Even you are not noticing any severe problems yet; the problems will start showing themselves soon enough. That said, it is better to get a new heater and spare yourself from all the headaches.

3. Low Volume of Hot Water

If your water heater no longer heats the water as much as before, it could have a declining function. One example is when you’re suddenly taking lukewarm showers instead of hot ones.

4. Higher Heating Bills than Usual

Your household’s hot water accounts for a good chunk of your heating expenses. If your water heater is not as efficient as it used to be, it will reflect on your bill. A seemingly excessive increase in your water bill means it’s time to consider replacing your water heater. Look for a more energy-efficient one.

5. Extreme Corrosion

The biggest sign that you have a corroded water heater is when the water is getting a reddish tint. This means that the inside of the tank is already rusted and requires replacement soon.

6. Frequent and Costly Repairs

Keep track of how many times your old heater requires replacement in a year. If you counted a lot, then it should convince you to invest in a new one. If the technician visits your home more than twice yearly for repairs, it indicates the need for a replacement.

Getting a new water heater may be quite expensive. However, frequent repairs are even more so. You might not overthink about the repair bills, but they do add up quickly. Aside from that, you will have to go through all the stress because of your faulty water heater.

Why Do I Have Hot Water but No Cold Water?

If no cold water is a widespread issue throughout your home, it could be a problem with the shutoff valve. Someone may have turned off the main water supply line’s valve accidentally. If that’s the case, turn on the valve back and get back to your shower.

However, if other faucets have cold water, it could be because the pressure-balancing valve is defective. In that case, you may need to have the valve cartridge replaced. Contacting a professional plumber can also help.

Gas or Electric Water Heater – Which One to Choose?

no hot water pressure, but cold is fine

If you decide to get a new water heater, the next thing to decide on is the kind you should get. Should it be gas or electric? Here are a couple of factors to consider when making the decision:

1. Installation

Installing both electric and gas water heaters will require proper permits. Electric water heaters are much easier to install, though. The main reason is that all homes already have electricity, but not all have gas service.

It can be costly to get a plumber to connect your house to the municipal gas supply line. You will also have to pay for the permits and application for the service.

2. Size

Electric water heaters are significantly smaller than gas heaters, especially the point-of-use models. These are the heaters that heat water on demand. There are also electric tank water heaters that come in various sizes.

On the other hand, there are no point-of-use gas water heaters; they are all tank models. This means that gas-powered heaters will always take up a lot of space.

3. Cost

Most electric water heaters cost anywhere between $500 to $800. Meanwhile, gas-powered heaters will set you back anywhere between $600 to $800, not including installation costs.

4. Safety

Electric water heaters are generally safer to use compared to gas-powered heaters. Electric heaters do not require the use of an open flame and flammable gases. When they do malfunction, they will trip the circuit breaker, thereby preventing further damage.

Meanwhile, a gas-powered water heater uses flammable gas. It usually has a pilot flame that’s always lit.

5. Operating Costs

Gas usually costs less compared to electricity, around 33% cheaper. Electric water heaters cost around $42 per month to use, while gas costs around $3o.

6. Lifespan

Because electric water heaters work much cleaner than gas-powered heaters, they can also last significantly longer. Gas heaters can typically last between 8 and 15 years. Most electric water heaters can last up to 15 years easily.

Conclusion – Hot Water Not Working But Cold Is

The usual culprit when you are not getting hot water in your home is a busted thermostat. However, the heater can still malfunction even if the thermostat is working fine. It could be because of sedimentary buildup in the tank triggered by a lack of proper maintenance.

If simple fixes are not enough to work properly again, buying a new one may be a viable move. You can cut your losses with it, especially if you have already spent a lot on heating bills and repairs.