Why is my Shower Cold?

Reasons there is no hot water, and how to troubleshoot and fix.

You come home from a long, tiring day at work, looking forward to your warm, steamy shower before bed. You hang up your coat, ditch your work clothes by the bed, and walk into the bathroom all excited. You undress, and get ready for your shower, put on your shower cap, prepare all the lotions and potions you will use, and you jump in.

You twist the knob and turn on the water, and it’s cold. “I’ll give it a minute”, you say.

Nope. It’s freezing cold. You’re now all cold, wet, and still filthy. And that’s not a very pleasant feeling. This is all usually followed by hours of frustration, and a ritual of reciting, “why did this have to ruin a brilliant day?”.

I mean, of course – we’ve got you covered. Cold showers do happen – they’re a part of life. But if you don’t have thousands to pay a professional to fix it for you, let’s get you up by your heater with your tools – or just with your hands, if tools aren’t necessary.

But where do we begin? The answer is simple – the shower knob. Did you actually turn on the hot water? Oh. Okay, never mind.

This issue can be incredibly frustrating. It is enough to take a good day and make it bad, or take a bad day and make it worse. Your shower is probably one of the most pleasant experiences of the day for you, so don’t let it be ruined by paltry malfunctions and wobbles.

So, with all that said, I think we can proceed onto the main article – what are the main issues that could be causing a lack of hot water? What can you do about it? How expensive is it to fix? Do you need to hire a professional?

To that last question, most of the time the answer is absolutely not. Save yourself a few hundred dollars every few months by fixing your cold-water problems yourself.

Let us begin!

Have you simply run out of hot water?

If your household/accommodation has a tank-based water heating system, you may have simply just run out of hot water. This usually happens when many people in your household use hot water simultaneously, or use a lot of hot water consecutively.

For example, this usually happens when there are multiple family members using multiple different bathrooms and showers, or there’s somebody cleaning the dishes or the car, and / or the dishwasher is running. A lot of hot water usage in one household can drain even the very largest of hot water tanks.

Even if you don’t actually have a hot water tank, and instead have a tankless water heater or similar, you can still face the problem of not having enough hot water to use.

A large number of tankless water heaters – at least those designed for domestic use – have a reasonably low “gallons per minute” heating rating. As a result of this, a lower GPM tankless water heater is not able to keep up with demand, as it is not able to effectively heat such a volume of water.

If this is the case, the fix is quite simple. Very simple in fact. Either postpone your shower until your family members have finished their household jobs involving hot water, or remove them from the property. Otherwise, if neither of these options apply to you, simply forbid them from using hot water.

Yes, the solution for tankless water heaters is really that simple. Usually, the reason why a tankless water heater can’t keep up with demand is simply because hot water demand is too high. So decrease the demand by decreasing hot water use, and don’t use more than two hot water sources simultaneously. Rather, possibly negotiate with other inhabitants to use hot water outlets consecutively, rather than simultaneously. The fixes really don’t get much simpler than this.

However, if, on the other hand, you have a tank-based, traditional water heating system, and it turns out that your tank is drained of hot water, you’ll be facing a different problem. But the solution to this is nearly as simple as the solution to tankless water heaters.

The solution is merely to wait. Refrain from using any hot water sources for a while (sorry, you’re going to have to postpone that shower) and come back to them once the tank has filled and the water heated.

If you’ve run out of hot water, the solution is to simply get more!

Is your water heater working?

This may seem quite obvious, but many don’t seem to think about this before calling their plumber or other certified professional in water works.

The second question to ask is – “is my water heater working? Is it on?”. You will find that a lot of the time this too is the problem, and you may just need to fix it or turn it back on.

How hard can it be? Well. Every water heater is designed differently, but we’ll cover the generics here for the sake of simplicity.

If you have a tankless water heater, firstly check if there is a gas supply (if you have a gas heater) to the tankless water heating unit, or check that the circuit breakers have not popped. If there is no gas/your circuit breakers have popped, there is no way that your water will be warm. For this, the solution is really quite simple.

If you have got a gas-based tankless water heater, simply turn the valve to allow gas flow in, and adjust the knobs on the unit – or use buttons if you have them – to set the temperature, and get back in the shower. However, if you have got an electric tankless water heating unit, the story really becomes quite different. You need to know where and be able to locate the switchboard in your house is. Once there, switch back any switches that have turned off, and your electric tankless water heater should be back in action. Simply adjust it how you like your water, and proceed!

Now, sometimes the circuit breaker will keep popping. In this case, you can infer that there is something wrong with the installation of your unit, as the circuit breaker is there to protect you from a lethal shock of current. In this case, do not attempt to mess with or tamper with your electric unit, rather, call a licenced professional who is skilled in these operations.

Attempting to touch the system when it is continuously popping can lead to catastrophe through loss of life or limb. Do not attempt this without certification or in the presence of a trusted professional.

But what about tank-based water heaters? Well this, again, is an entirely different story.

Tank based water heaters, similarly to their more modern, more technologically advanced tankless counterparts, usually work in a similar way. If they are powered by gas, ensure the gas is flowing and the ignition system (refer to manufacturer’s manual) is in good condition. This is different for every tank-based water heater, so always refer to the instruction manual.

However, if you happen to have an electric tank-based water heater, check the circuit breaker again. If it keeps popping after being reset, then you may have a problem, or your tank may be leaking and shorting out the electrical system. This is never a good sign, so turn off the mains power and call a licensed professional as soon as possible.

Did you actually set up your heater?

If all of the above seems perfectly normal, another question to ask would be – “Did I actually set up my heater as I would like it?”. This is a question that many people seem to skip, and instantly call their local plumber. I mean, sure, you could always do that, but why not save yourself a few dollars here and there, and invest it in a family holiday or a trip somewhere instead of a shower that you can get to work on your own?

Often, when purchasing a new tankless or tank-based water heater, whichever one, people seem to think that they are already set up by default and only require installation. Whilst this is the case for the vast majority, some are not pre- ‘set-up’. This usually leads to frustrated customers calling up warranty and guarantee services, trying to get a full refund for a faulty product that was never actually faulty in the first place, only to find themselves embarrassed at the customer service desk after forming a mile long queue behind them.

But how do we solve this? Well, the answer really is quite simply. You should, as always, refer to your specific model’s instruction manual, which can usually be found online. However, here we will cover the simple, generic steps. To solve this problem, it is usually perfectly sufficient to simply locate the temperature knob on the front of the heater. This usually applies to both gas or electric tankless or tank-based water heaters, with the exception of a few. If you have purchased a more technologically advanced heater, or an industrial heater, you may find that there is no temperature knob on the front of the appliance – or there may not be any knobs visible. In this situation, you should always consult your instruction manual, as typically, the knobs and adjusting mechanisms are located on the back of the water heater, sometimes hidden behind a panel that requires tools such as screwdrivers to remove. This can be a time-consuming process, as there are even some water heaters that must be removed from the wall or have their tanks removed to access the water supply.

What often happens is that upon purchasing a water heater, the heat setting is set to “zero” or “neutral”. This means that even if there is current flowing through the heating element or gas flowing into the heater, you are not getting your desired temperature because the heater is not actually transferring any of that energy to the water itself.

To fix this, simply turn up the heat on the heater. This is usually done through buttons or knobs, and after this you can usually just return to your shower and enjoy your wonderful new hot water supply.

If you haven’t set up your heater, do so now. This is yet another common problem that may require more than just two minutes of your time. But it’s always worth it in the end – nothing beats a great shower after work.

Does your mixer tap work?

This is probably the most complicated fix of them all. If all the other showers in your household are working, and all hot water taps are actually releasing hot water, then this may be the issue.

However, it is always important to notice that if you are not experienced in this field, or do not do a lot of DIY, you may struggle to perform this fix. For this reason, we recommend calling a plumber.

The actual mixer taps themselves are not at all very expensive. Some can be purchased for as little as $8 off amazon, and seem to have perfect reviews.

For this, we simply recommend calling a plumber. This job is too complicated to explain in a 2000 word article, and you risk damaging a hot water outlet if you are inexperienced.

Final Words

These are common problems that most common people will experience during their lifetimes with their showers. This is nothing to worry about, and these issues are very easily overcome with patience.

However, as always, DIY jobs do carry with them a lot of risk. So, if you aren’t too sure about something, always call your plumber or a similar professional in water works. If you’re lucky, and purchased your heater form a reputable company, you will find that they will typically solve your problems for you quickly.

About the author

Steve Bates

Hi, I'm Steve and I currently reside in Chicago, Illinois. Although for most of the last 20 years I was a partner in a HVAC company down in Austin, Texas.

I understand the frustration involved with dealing with water heater repairs and replacing or upgrading to a new, more efficient model.

My aim is offer some basic advice on fixing home hot water systems. And if a repair isn't possible, then to make the process of selecting a new water heater – be it gas or electric - as simple as possible.

So that you can save money and have a safe and reliable hot water system in your home for many years to come.