Highlands Ranch Water Heater Not Heating? Plumbing Fixes

Estimated Read Time: 9 minutes

Is your water heater not heating or only producing lukewarm water? Cold showers are more than inconvenient. In this guide, you’ll get quick DIY checks, proven fixes, and clear signs it’s time to call a pro. We’ll walk through the most common issues homeowners face in Denver homes and how to solve them fast. If you need help today, our same‑day team is standing by.

1) Tripped breaker, failed heating element, or thermostat issues (electric units)

If you have an electric water heater, start with power and safety. Turn the breaker off, remove the upper access panel, and press the red high‑limit reset on the thermostat. If it trips again, you likely have a failing element or thermostat.

Quick checks you can do safely:

1. Verify the dedicated breaker is on and not hot to the touch.
2. Inspect wiring at the upper and lower thermostats for signs of scorching.
3. With power off and wires removed, use a multimeter to test heating element resistance. A healthy element usually reads 10–20 ohms.
4. Replace a failed element or thermostat in matched pairs if the unit is older, then restore power.

When to call a pro:

• Repeated trips of the high‑limit switch.
• Evidence of melted wiring or a burned terminal.
• You do not have the right meter or replacement parts.

Professional note: Our Denver team stocks universal elements, thermostats, and gaskets on the truck, so most electric‑side failures are fixed in a single visit. That prevents the cold‑shower repeat tomorrow morning.

2) Pilot light out or ignition failure (gas units)

No hot water and a gas heater? Check for a pilot flame on older models or verify the status light on electronic ignition units. If the pilot is out, follow the lighting instructions on the tank. Hold the knob to “Pilot,” press the igniter, keep holding for 30–60 seconds, then turn to “On.”

Common causes when the flame will not stay lit:

1. Dirty or failing thermocouple or flame sensor.
2. Clogged pilot orifice from dust or rust.
3. Faulty gas control valve.
4. Inadequate combustion air or downdrafts in high winds.

What you can try:

• Vacuum dust around the burner area with the gas off.
• Gently clean the flame sensor or thermocouple with fine steel wool.

Stop and call a licensed tech if you smell gas, see soot buildup, or the pilot repeatedly goes out. We perform combustion analysis, verify manifold pressure, and replace unsafe components to manufacturer specs. That keeps efficiency high and reduces the chance of a mid‑shower shutdown.

3) Sediment buildup reducing heat transfer and capacity

Colorado’s Front Range water is moderately hard, and sediment becomes the silent efficiency killer in tanks. Denver Water reports moderately hard water, which accelerates mineral buildup on the bottom of the tank. That layer insulates the burner or elements, causing popping noises, longer heat cycles, and lukewarm water under load.

DIY flush steps:

1. Turn power or gas control to Off. Close the cold supply valve.
2. Connect a hose to the drain valve and run it outside or to a floor drain.
3. Open a hot faucet upstairs to break the vacuum, then open the drain.
4. Once empty, briefly open the cold valve to stir remaining sediment, then drain again.
5. Close the drain, refill, purge air at faucets, and restore power or gas.

If the drain valve is clogged or the tank is older and noisy, professional descaling and anode inspection help. We recommend annual flushing. Members of our Home Care Club get routine flushes and safety checks that extend tank life and lower gas or electric use.

4) Dip tube failure or mixing valve crossover causing lukewarm water

A broken dip tube lets incoming cold water mix at the top of the tank instead of being directed to the bottom to heat. The result is quick bursts of hot water that turn lukewarm fast. Similarly, a failed shower mixing valve can allow cold water to cross over into the hot line, cooling the entire system.

How to spot it:

• Hot water turns cool within a minute or two.
• One shower affects the whole home’s hot water temperature.
• No error lights, no pilot issues, and the burner cycles normally.

What to do:

1. Test fixtures: shut off cold supplies to suspect faucets and retest hot water.
2. If crossover disappears, replace that mixing valve cartridge.
3. If not, inspect and replace the heater’s dip tube. This is a low‑cost part but requires proper sizing and sealing.

Our techs carry universal dip tubes and rebuild kits for common mixing valves. We also check the anode and T&P valve while the plumbing is open, so you get full value from one service call.

5) Incorrect sizing or end‑of‑life efficiency loss

Even a perfectly working heater cannot produce what it was never sized to deliver. If your household grew from two to five people, your shower schedule stretches any 40‑gallon tank. Age also matters. Most tanks last 10 to 12 years with proper maintenance; efficiency drops and failure risk rises after that.

Clear signs it is time to upgrade:

• Frequent lukewarm showers at peak times.
• Visible rust, water around the base, or a leaking tank.
• Repeated repair visits on a unit over 10 years old.

Upgrade paths:

1. High‑efficiency tank models for budget‑friendly, familiar operation.
2. Tankless for endless hot water and space savings. The Department of Energy notes tankless can be 8 to 34 percent more efficient depending on usage patterns.
3. Hybrid heat pump water heaters for strong efficiency gains and dehumidification benefits.

We help you right‑size to your peak demand, code requirements, and venting conditions. Brothers follows 2015 NAECA efficiency standards and local code, removes the old unit, and sets the new heater for safe, long life.

Prevention and pro tips for reliable hot water

A little care prevents most no‑heat emergencies:

1. Flush the tank annually to remove sediment. Many Denver homes benefit from a simple sediment flush each year.
2. Test the T&P valve and inspect the anode every 1 to 3 years. Replace the anode when more than half consumed.
3. Consider an expansion tank if you have a closed plumbing system to protect the tank and fixtures.
4. Install a recirculation pump for faster hot water at distant fixtures and less wasted water.
5. Join a maintenance plan. Our Home Care Club includes scheduled inspections that catch small issues before they become breakdowns.

Safety must‑knows:

• Turn off power or gas before opening access panels.
• If you smell gas or see scorching, call a professional immediately.
• Never cap a dripping T&P valve. That is a critical safety device.

Fact check for smart decisions:

• Water heating is one of the top energy uses in a home, often around 18 percent of total energy consumption, so efficiency upgrades pay back.
• Colorado winters and wind gusts can affect venting and draft. We verify combustion air and vent configuration on every gas install or repair.

Need help now? Brothers offers same‑day service, upfront pricing, and financing for replacements. We carry parts for most brands and handle traditional, tankless, hybrid, gas, and electric models in one visit.

Special Offers for Denver Homeowners

• Save $150 on Water Heater Installation. Call (720) 994-7055 or schedule at https://www.brothersplumbing.com/ and mention the “$150 Off Installation” offer. Only one coupon per visit.
• Save $50 on Work Performed on Boulder Tankless Water Heaters. Call now or book online and reference the “$50 Off Tankless Work” offer. Only one coupon per visit.

These deals pair perfectly with same‑day service and financing. Call (720) 994-7055 to claim your savings.

What Homeowners Are Saying

"Scott C and his associate were very quick and professional! Our hot water heater had stopped working and he cleaned it out and had it back on within an hour. Fabulous!"
–Scott C., Water Heater Repair

"12/21 Ian was very professional, clean and friendly. The new hot water heater goes in tomorrow. They are jumping on it immediately after we have been without hot water since last Friday. Happy so far. 12/22 The Master Plumber Richard P came today bright and early despite the -14 degree temperature and 6 inches of snow! Very professional and very informative before, during and after the hot water heater installation. It was a major operation due to extra piping and valves and upgrades. My old heater was 23 years old. I am very happy with the service from Richard and his apprentice. They were nice gentlemen who took care of business. Thank you, Brothers Plumbing for being here quickly when I needed help!! *****"
–Richard P., Water Heater Installation

"Chuck and Francisco did a great job problem solving an issue with my water heater that was under warranty. I had purchased the water heater from Brother's three years ago. They were punctual, friendly, and knowledgeable. Although Brother's is expensive, I was grateful the water heater we purchased came with a 6-year warranty which covered all the repairs today."
–Chuck and Francisco, Warranty Repair

"As usual, great service from Brothers Plumbing. The technician took time answer our questions and explained how out tank less water heater works"
–Tankless Customer, Tankless Water Heater

Frequently Asked Questions

Why is my water heater running but water is still cold?

Power or gas supply issues, failed elements or thermostat, a dirty flame sensor, or a broken dip tube can all cause no‑heat. Start with breaker and pilot checks, then call if problems persist.

How often should I flush my water heater in Denver?

Once per year is a smart baseline. Our region’s moderately hard water leads to faster sediment buildup, so annual flushing protects performance and extends life.

When should I replace instead of repair?

If the tank is 10 to 12 years old, leaking, or needs frequent repairs, replacement is usually the best value. Upgrading boosts efficiency and reliability.

Will a tankless water heater solve lukewarm showers?

Yes, when properly sized. Tankless units provide continuous hot water, but gas line and venting must meet specifications. A load calculation ensures the right model.

Is a T&P valve drip dangerous?

It signals pressure or temperature issues. Never cap it. Call a pro to test system pressure, expansion tank, and valve function.

Bottom Line

If your water heater is not heating, the fix is often simple: reset a tripped control, relight a pilot, flush sediment, or replace a small part. When age, sizing, or safety is the problem, upgrading restores comfort and cuts energy use. For fast help with a water heater not heating in Denver, call (720) 994-7055 or schedule at https://www.brothersplumbing.com/. Ask about $150 off installation.

Ready for Hot Water Again?

• Call now: (720) 994-7055
• Schedule online: https://www.brothersplumbing.com/
• Current offer: $150 off water heater installation. Only one coupon per visit.

Same‑day service. Licensed, certified techs. Upfront pricing. Let Brothers get your hot water back today.

About Brothers Plumbing, Heating, and Electric

Brothers Plumbing, Heating, and Electric is Denver’s one‑stop home services team. Our licensed, certified pros deliver same‑day solutions, transparent pricing, and 100% satisfaction. We are BBB accredited with an A+ rating and recognized with awards including 2024 Colorado Titan 100 and Denver Post Top Workplace. We install and service traditional, tankless, and hybrid water heaters, follow 2015 NAECA efficiency standards, and offer financing. Local, trusted, and ready to help.