Hot Water Heater Repair in Denver: Leaks, Noise, No Heat

By the Denver Urgent Plumber team · Updated November 2026

What to do first

1. If you smell gas, do not touch light switches or the heater. Leave the house and call your gas utility or 911 from outside.
2. Turn off the cold water supply valve on the pipe above the water heater.
3. For a gas heater, turn the gas control knob to off. For an electric heater, switch off its breaker at the panel.
4. Move boxes, rugs and anything else that can soak up water away from the tank.
5. Take photos of the heater, the label and any water on the floor before you clean up.

When do you need hot water heater repair right away?

You need hot water heater repair right away when water is pooling under the tank, the relief valve is spraying, you smell gas, or the heater makes loud popping or banging sounds that keep getting worse. Shut things off and call.

Other problems can usually wait for a scheduled visit. Lukewarm water, hot water that runs out faster than it used to, or a slight rumble when the burner runs are signs the heater needs attention soon. If you have no hot water at all, the no hot water guide walks through the simple checks first.

Why is my water heater leaking from the bottom?

A water heater leaking from the bottom is often a sign the tank itself has rusted through, which cannot be patched. But water can also run down from a loose fitting above, drip from the drain valve near the base, or come out of the relief valve pipe.

Dry the area and watch where new water appears. Water at a valve or fitting may be a simple fix. Water seeping from under the tank jacket usually means the tank is failing. Either way, turn off the cold water valve and call so a local provider can confirm the source.

What does it mean when the relief valve is dripping or spraying?

The temperature and pressure relief valve opens when the water in the tank gets too hot or the pressure gets too high. A drip or burst of water from the pipe at the side of the tank means the valve is doing its job, or the valve itself is worn out.

Never cap or plug that pipe. Turn off the heat source and the cold water, and stay clear of the pipe, since the water can be very hot. A provider can check the pressure, the thermostat and the valve to find the problem.

Why is my water heater making popping or rumbling noises?

Popping, rumbling or crackling noises usually come from sediment, a layer of minerals that settles on the bottom of the tank. When the burner heats the water, small steam bubbles push up through that layer and make noise. Sediment can also make the heater work harder.

Flushing the tank can help if the buildup is not too heavy. A loud bang, a hissing sound, or noise along with a leak is a reason to shut the heater off and call. Do not plug or cap the relief valve, and do not keep relighting a pilot that will not stay lit.

Why does my hot water look rusty or smell like rotten eggs?

Rusty or brown hot water often means the inside of the tank or the anode rod is wearing out. If both hot and cold water look rusty, the cause may be in the pipes or the water supply instead.

A rotten egg smell from hot water only is often a reaction between the anode rod and bacteria in the tank. It is common, and a provider can explain whether flushing the tank or swapping the anode rod makes sense. A gas smell near the heater is different: leave the house and call your gas utility.

Is it worth repairing an old water heater or should it be replaced?

A water heater is often worth repairing when the problem is a part like a thermostat, heating element, igniter, gas control or relief valve, and the tank itself is sound. Replacement usually makes more sense when the tank is leaking or rusted through.

The model and serial number on the tank label can help the provider tell you the heater's age. The water heater repair vs. replacement guide covers the trade-offs.

What happens during the visit?

The visit starts with an inspection. The provider looks at the tank, the connections, the relief valve, the venting on a gas unit and the controls. They may ask how old the heater is and when the problem started. They should explain what they found in plain words.

Next, they explain your options. That might be replacing a single part, flushing the tank, or replacing the heater if the tank has failed. You should get a written quote before any work begins, and you can take time to compare options. If you rent, share the quote with your landlord before you approve anything. The how it works page explains how calls are connected. For more on common parts and problems, see water heater repair in Denver.

Water heater problems in Denver and nearby suburbs

Water quality plays a part in how fast sediment builds up in a tank. Denver Water says its southern system water is considered moderately hard and its northern system water is considered somewhat soft, and that the water is slightly harder in winter. Aurora Water lists its hardness at an average of 136 ppm.

Know where to shut the water off before a leak starts. Denver Water says the main shutoff in most single-family homes is in the basement or crawl space, on a wall facing the street. Denver Water also says it is not responsible for water damage caused by a property's internal plumbing. If water damages your home, the Colorado Division of Insurance advises contacting your insurer as soon as possible, taking steps to prevent further damage, and getting the insurer's instructions before making repairs. Check your policy and document everything.

Calls come from across the metro, including Lakewood, Aurora, Centennial, Littleton, Wheat Ridge and Highlands Ranch.

Related pages

• Water heater repair in Denver
• No hot water? What to check first
• Water heater repair vs. replacement
• Emergency plumber in Lakewood