Water heater repair in Wolcott, Prospect and Cheshire

No hot water? First checks for tank, tankless and boiler-fed heaters

No hot water starts with one question: what kind of heater do you have? An electric tank, a gas tank, a tankless unit and an indirect tank fed by your boiler each stop for different reasons, and each maker’s own manual starts with a different short list of things that are safe to look at.

This page goes heater by heater, safe checks first, then the point where it becomes a water heater repair call for homes in Wolcott, Prospect and Cheshire. It does not tell you to light, clean, open or replace anything on a gas or electric heater. If you smell gas, leave the house and call your gas company or 911 from a neighbor’s home, as Connecticut PURA advises.

Read the model off the label on the heater and have it ready. Then find your row. The first column is what is safe to look at. The second is where we stop you, and the sections below give each maker’s own wording so you can check us.

Both makers start the no-hot-water list in the same place. A. O. Smith’s use and care guide lists “No power to heater” and the action “Check for blown fuses or tripped breaker”. Rheem’s manual for its electronic-control electric heaters (AP21980) lists a blown fuse or tripped breaker with the fix “Replace fuse or reset circuit breaker.” It also lists a thermostat set too low, an electric supply that is off, and open hot water faucets.

A breaker that trips again is not a reset problem. Bradford White’s electric water heater service manual, written for technicians, says an element shorted to ground “will in most cases cause the circuit breaker in the service panel to open or shut off”. And before anyone touches a panel, A. O. Smith’s no-hot-water page says to “Turn off power at the circuit breaker before touching anything.”

The temperature setting on a standard electric tank sits behind a metal access cover with insulation folded over it, and A. O. Smith’s guide walks through removing it. Checking it means opening a panel on a live appliance, so switch the breaker off first, or tell us what the heater is doing and let us look. The scald risk is real. The same guide says “There is a hot water scald potential if the thermostat is set too high.”

Why the second trip matters: Bradford White’s manual says “Repeated actuation of the ECO is usually the result of a grounded element.” ECO is the maker’s name for the high-limit cutoff. A. O. Smith’s own page puts it the same way for owners, saying repeated tripping points to “shorted elements or faulty thermostats”.

One more rule from both manuals, and it matters after a leak or a drained tank. Rheem says never to turn the heater on unless it is filled with water, and A. O. Smith says “Do not turn on power to the water heater unless it is completely filled with water.”

That is where a service call starts. Bradford White’s service manual says “Most common cause for improper electric water heater operation can be linked to heating element failure.” The manual’s own plan for a technician runs in order: confirm service voltage and that the high limit has not tripped, test the elements, then test the thermostats. None of it is a job to learn on your own heater.

Gas first. Connecticut PURA says “If the smell is strong or you are unsure, leave the building and then call.” It also says “NEVER turn the gas back on once it has been shut off due to a safety concern. Call your local gas company for assistance.” The Consumer Product Safety Commission lists headache, dizziness, weakness and nausea among the symptoms of carbon monoxide poisoning, and says if you suspect it, get outside to fresh air immediately and then call 911.

With no smell and no alarm, the safe look is at the temperature dial. Rheem’s manual for its gas tank heaters (AP23059) lists a gas control set too low among the causes of not enough or no hot water, and its table also lists a heavy draw: “Wait for the water heater to recover after an abnormal demand.” Rheem’s manual puts the gas control near the bottom of the tank and marks the dial rim at about 120 degrees. Moving the dial is the adjustment the manual describes for owners. The gas control behind it is not.

Rheem’s chart also says the pilot may be out and to relight it from the lighting instructions. We would rather you did not, and the same chart shows why. A pilot that will not stay lit is sent to a qualified technician (a loose or defective thermocouple, a defective safety magnet, a tripped combustion shutoff device), and the chart closes with “For your safety DO NOT attempt repair of gas piping, gas control (thermostat), burners, vent connectors or other safety devices. Refer repairs to qualified service personnel.” A. O. Smith’s page tells owners to clean a clogged burner. We part company with that, and it agrees on the valve: “This component requires precise calibration and should be inspected and replaced by a professional if found to be defective.”

Some gas heaters shut themselves down on purpose. Bradford White’s service manual for its Defender Safety System heaters says the safety switch “also deactivates the burner and pilot in the unlikely event of restricted airflow caused by severe lint, dust, or oil accumulation on the arrestor plate”, and its chart puts the reset button on an inner door of the heater. We do not ask homeowners to open that door. A heater that shuts down and will not relight is a call, with the make and model ready.

A tankless heater tells you what it thinks is wrong. Navien’s user manual for the NPE heaters says “If an error message appears, you can try resetting the water heater to resolve the problem.” The reset is a press of the Back button. If that does not clear it, the manual says to “contact an authorized technician, a licensed professional, or Technical Support”. Rinnai’s installation and operation manual puts a warning over its code table: “Some of the checks below should be performed by a licensed professional. Consumers should never attempt any action that they are not qualified to perform.”

Two checks cost nothing. Navien’s chart asks whether the set temperature is too low and whether the hot tap is open wide enough to draw at least 0.5 gallons per minute. Rinnai’s no-code line says the same thing from the other side: “Verify you have at least the minimum flow rate required to fire unit.” A tap opened a crack may not move enough water to start the burner.

In a Connecticut winter there is one more, and it is outside. Rinnai’s maintenance section says “Keep the area around flue terminal free of snow and ice.” The heater will not function properly, it adds, if the combustion air or exhaust pipes are blocked. Look at the vent terminal on the outside wall from where you stand. If it looks blocked, tell us.

The codes are where the makers’ lists show how fast a tankless call turns into gas and venting work. Here is what each maker’s own table says for the codes we hear about most.

The makers are plain about the limit. Navien’s support page answers a homeowner who asks for help: “there is only a limited amount of troubleshooting that can be done with a homeowner/end-user”. Rinnai’s separate diagnostic codes guide opens with “Only trained and qualified professionals are permitted to follow the instructions in this document.” and warns “DO NOT adjust the internal gas valve.” The Rinnai flame check on code 11 is the technician’s own: “Visually inspect the burner flame through the view glass.”

An indirect heater stores hot water in a tank and gets its heat from the boiler, as our indirect vs. tankless guide explains for buyers. That guide is the buying side and this page does not repeat it. This is the repair side, and it starts somewhere simple: the tank can only be as hot as the boiler makes it.

Bradford White’s troubleshooting guide for its double-wall indirect-fired heaters lists causes of no hot water at the faucet in this order. The first is “Boiler does not operate”, and the fixes begin with the boiler’s own instructions, its main service switch and the fused disconnect. Then it lists a circulator that is not running, a tripped high limit on the tank thermostat, a wrong thermostat setting, a zone valve that does not open, an electrical fault, scale on the coil and a clogged strainer.

It is a zone like any other. Bradford White’s manual says “The indirect-fired water heater must be installed as a zone separate from the space heating system.” So if one room or one zone is cold and the hot water is fine, our one heating zone guide is the right read, and if the whole house is cold, start with boiler running but the house is cold.

Not enough hot water, as opposed to none, has its own rows. Bradford White lists “Undersized boiler with no priority to domestic hot water”, among others, with the fix of rewiring for priority. Lochinvar’s manual for its Squire indirect tanks has a start-up check for exactly this connection: “Make sure that the boiler shuts down when the indirect water heater is satisfied.” Its own scope is clear, too. It says it “must only be used by a qualified heating installer / service technician”. The one owner task it lists is a monthly look: “Visually check valves, pipes, and fittings for leaks. Call a qualified service technician to repair leaks.”

Three signs get people thinking about a new heater. The manufacturers do not say the same thing about all three, so here is what each one actually says.

A leak at the bottom of the tank

This is the one that points to replacement. Rheem says “Leaks from the bottom often signal tank corrosion that requires replacement.” (Rheem, what to do before calling a plumber). A. O. Smith’s page agrees: “if the tank itself is leaking, the entire water heater usually needs to be replaced”. The same page warns that condensation on a gas heater is sometimes mistaken for a leak, so look closely at where the water comes from. Rheem’s article suggests you “photograph any visible leaks, rust, or unusual condensation around the tank” before you call.

Rusty water

Do not condemn the heater on color alone. A. O. Smith’s technical bulletin 21 on discolored water says “it is a rare occurrence for today’s high quality glass lined tanks to have a lining failure significant enough to allow water to contact enough bare metal to discolor the contents of even a small tank”. It says the most common cause of rusty water is a “non-toxic iron reducing bacteria”, and adds that the bacteria can wear out the anode rod early. So the useful question is where the rust shows up and whether the anode rod needs a look. Tell us if it is in the hot taps only or in the cold too.

A pop, hiss or sizzle

On an electric tank, A. O. Smith ties “crackling, popping or hissing sounds” to scale on the heating elements, and Bradford White’s manual lists noisy elements as lime on the elements to be cleaned or replaced. That is an element visit, not an automatic new heater. On a gas tank, Rheem says “Drops of water falling on the burner can produce a sizzling or pinging sound.” and that new-fill condensation is normal; condensation that keeps going is a reason to check the piping for leaks.

Age is what turns a repair into a replacement conversation. Rheem says “If your unit is close to or over 10 years old and is having issues, replacing it usually costs less than repairing it.” Tell us the age if you know it. An old heater that is also leaking at the base meets both of Rheem’s tests above.

Each maker prints an order for the technician, and it shows what a visit covers. On an electric tank that is the Bradford White plan above: voltage and the high limit first, then elements, then thermostats. On a gas tank the Bradford White service manual charts run from gas supply and line pressure through the pilot, thermocouple and safety switches, with the combustion air and flame arrestor checked when a heater shuts down on its own. On a tankless unit it is the code history and then the maker’s sequence, which on a Rinnai code 11 runs from gas on and air purged to inlet gas pressure, the igniter spark and the flame rod (Rinnai diagnostic codes guide). On an indirect it is the boiler call, the circulator and zone, and the tank’s thermostat before the coil.

When you call 203-756-5040, have four things ready: the type of heater and the model on its label, any code on the display, whether the boiler is running and the house is heating, and whether there is water on the floor. A real person answers around the clock. We work on tank, tankless and indirect heaters across the Greater Waterbury area, and Wolcott, Prospect and Cheshire are all inside it.

Indirect water heater vs. tankless: which fits a home with a boiler? Boiler running but the house is cold? A Connecticut homeowner’s guide How often does a boiler need service in Connecticut? (2026)

American Heating and Air Conditioning Service

Family owned HVAC contractor, 1114 Middlebury Rd, Watertown CT 06795

We have installed and serviced furnaces, boilers and water heaters across the Greater Waterbury area since 1978, our technicians are NATE certified, and we answer the phone 24 hours a day for emergencies. Questions about anything in this article? Call us at 203-756-5040.

1. A. O. Smith, Residential Electric Water Heater Installation Instructions and Use and Care Guide (part 321249-000)
2. A. O. Smith, Is Your Hot Water Not Getting Hot? Common Causes and What To Do About Them
3. A. O. Smith, Technical Bulletin 21, Discolored Water
4. Rheem, Use and Care Manual, Electric Residential Water Heaters with Electronic Control (AP21980 Rev 02)
5. Rheem, Use and Care Manual, Residential Gas FVIR Certified Water Heaters (AP23059 Rev 01), hosted in Rheem’s product-document library
6. Rheem, What to Do Before Calling a Plumber or Replacing Your Water Heater
7. Bradford White, Residential Electric Water Heaters Service Manual (238-51544-00D, rev. 5/22)
8. Bradford White, Defender Safety System Flammable Vapor Ignition Resistant Water Heaters Service Manual (238-51542-00E, rev. 08/22)
9. Bradford White, Double-Wall Indirect-Fired Water Heater Installation and Operation Instruction Manual with Troubleshooting Guide (238-45085-00K, rev. 10/23)
10. Lochinvar, Squire Indirect Water Heater Installation and Operation Manual, models SIT030 to SIT119 (Rev X)
11. Rinnai, Tankless Water Heater (Residential) Installation and Operation Manual, N Series, U334-0771(02), sections 4.5 and 5.1
12. Rinnai, Troubleshooting Tankless Water Heater Diagnostic Codes (100000652)
13. Navien, NPE Condensing Water Heaters User’s Information Manual (NPE-180A2, NPE-210A2, NPE-240A2 and the S2 models), sections 3.3, 5.1 and 5.2
14. Navien, NPE-A2 Series FAQs
15. Connecticut Public Utilities Regulatory Authority, What To Do If You Smell Natural Gas
16. U.S. Consumer Product Safety Commission, Carbon Monoxide Information Center

References checked October 14, 2026. General homeowner information, not a substitute for the instructions supplied with your equipment or an on-site diagnosis. Manual wording differs by model and revision; the documents above are the ones quoted, and your heater’s own manual is the one that governs it.

The hero is an editorial image generated from one of the company’s own job photos; it is not a photograph of a specific customer’s home. All other photos are American Heating and Air Conditioning Service job photos from the company’s own library.

The pages behind this post, for when the water heater is the next job on the list.

• Water heater repair, maintenance and installation, tank and tankless
• Boiler repair, service and installation, the heat source behind an indirect heater
• Heating services for the Greater Waterbury area, furnaces, boilers and more
• Contact us for 24/7 emergency service, or call 203-756-5040