Hot Water Runs Out Fast

Hot Water Runs Out Too Fast | This is a gas water heater. I'm guessing it's what Arlen has in his home. Who's Arlen? Keep reading, silly!

Hot Water Runs Out Fast - Especially in Winter

Arlen is a subscriber to my FREE newsletter.  He knows I've been a master plumber since 1981 and would have some insight. He shared this with me:

My wife was taking a normal shower last week and suddenly ran out of hot water. I checked the water heater, and everything appeared to be ok. So I just bumped up the thermostat a bit and I took a shower with no problem. Since the Richmond 40 gallon is just about out of its 12-year warranty, I decided to do what you preach and that is contact the manufacturer. The service tech gave me this story about how the water is much colder in the winter and so naturally you have to turn the thermostat higher. I called BS at that point. Yes, the water gets colder, but I have never had to adjust the thermostat in the previous 12 years we've had the heater. So why does my hot water run out so fast? He had to answer to that. I did replace that anode rod and flushed it last summer per your suggestions. When I asked him about adding a second anode rod as you mentioned in your library, he said it was not possible.

When do I need to replace this heater? I don't want to push my luck and end up with no hot water on a Saturday night!! So what say ye?

Thanks, Tim!

Why Arlen's Hot Water Runs Out Too Fast

Let's unpack Arlen's conundrum. There are quite a few things that contributed to his wife jumping out of the shower faster than jack pops out of a box.

An intriguing and important clue he offered up is this has never been an issue in the previous twelve years. Let's assume the winter weather has been the same where Arlen lives, his wife is in the shower the same amount of time, and she adjusts the water temperature to the same heat level during each shower. I know, that's a big bag of assumptions.

If that's the case, there's a somewhat rare possibility the dip tube in Arlen's heater has worn out or has developed a defect.

What Does A Dip Tube Have to do With my Water Heater Running Out of Hot Water?

A dip tube is a long plastic tube that's like a straw but it's about 3/4-inch in diameter. You find these tubes on the cold-water inlet of water heaters. The dip tube directs incoming cold water to the bottom of the heater.

If no dip tube were in place, the incoming cold water could migrate sideways about ten inches and mix with the hot water that's leaving the hot-water outlet. Years ago, there was a spate of dip tubes that were made with an inferior plastic that caused them to disintegrate within the heater.

Was the Richmond Tech's Advice about Cold Water Correct?

If you live where it gets cold in the winter, and are on city water, yes the incoming cold water temperature is colder than in August. I say this assuming your city water department gets its water from a nearby river. If the water source is a deep well, your incoming water temperature should be about the same year-round. 

Your water heater running out of hot water in the winter might have to do with what maybe Arlen's wife did a few days ago.

If the bathroom was colder than normal during below-normal winter weather, it's common for a person to reduce the chill by raising the temperature of the water flowing from the showerhead. This, by default, means you'll use up more of the stored hot water in the water heater tank faster than normal.

Add to this the fact that the incoming cold water is colder and a 40-gallon water heater could struggle to deliver 120F hot water for more than five to seven minutes. It's all a matter of how many gallons of hot water are flowing through the shower faucet.

Why Didn't Arlen Run Out of Hot Water During His Shower?

Arlen was able to use less hot water per minute because the incoming temperature of the hot water at the shower valve was higher. This means he had to use more cold water and less hot water to not get scalded. Once again, we need to assume that the temperature of the water coming out of the showerhead is the same for both Arlen and his better half. This may not be true!

Your Hot Water Runs Out Quickly - What Can You Do?

If your hot water runs out too fast, you can install a tankless heater. I have one and they're magnificent.

This is my tankless water heater. It's also the boiler that heats my 4-bedroom home. The box is the size of a piece of checked luggage!

It's important to realize you shouldn't base your decision on buying a tankless water heater to save money. You should read the comments sent in by homeowners like you who have seen an increase in their fuel bills after installing a tankless heater. You can read those comments in a past tankless water heater column. I recommend that you also read my original tankless water heater column because I never received pushback from the manufacturers. That tells you everything I said in the column was TRUE.

How Much Life is Left in Arlen's Water Heater?

Since Arlen added a new anode rod, he might get another 12-15 years out of his heater. If you regularly replace the anode rod, a tank water heater can last for decades.

Get FREE BIDS from local plumbers that will replace your anode rod.