No hot water or a leaking tank: act first, then call
A water heater that leaks from the tank body is an emergency, because a split tank keeps emptying until someone shuts off the supply. Close the cold water valve on top of the heater, switch off the power at the breaker or turn the gas control to pilot, and call our 24/7 line.
A heater with no hot water and no leak can wait a few hours, but a cold house in January makes it urgent for families with children or older relatives. Tell the dispatcher what the heater is doing and what fuel it uses, so the plumber loads the right parts.
- Water pooling at the base of the tank: close the cold supply valve.
- Hot water that smells like rotten eggs or a rumble like popping corn.
- A gas smell near the heater: leave the house and call 911 or the gas utility first.
- A pressure relief valve that drips steadily or discharges hot water.
Common symptoms and what usually causes them
These pairings are typical, and the plumber confirms the cause with tests before replacing any part.
| Symptom | Likely cause | Typical repair |
|---|---|---|
| No hot water, electric heater | Failed heating element or thermostat, tripped limit switch | Test and replace the element or thermostat |
| No hot water, gas heater | Pilot out, bad thermocouple or gas valve | Relight, replace the thermocouple, check venting |
| Hot water runs out fast | Sediment buildup, broken dip tube or one failed element | Flush the tank, replace the dip tube or element |
| Popping or rumbling | Mineral sediment on the tank bottom | Flush, and decide if the tank is worth saving |
| Water at the base | Fitting leak or a failed tank | Tighten or replace the fitting, or replace the heater |
Tank leaking or no hot water?
Shut the cold water valve above the heater and call the 24/7 line.
When repair makes sense and when it does not
A new heating element, thermostat or thermocouple is a modest repair on a tank that is otherwise sound. A leak from the tank itself is different, because the steel has corroded through and no part will stop it. In that case the honest answer is replacement, and the water heater replacement page explains how that visit works.
The age of the heater matters. The data plate on the side lists a serial number that the manufacturer's website can decode into a build date. Ask the plumber to read it. If the heater is near the end of the usual range for its type, a large repair can be money spent on a tank that fails next year.
Gas, electric and tankless: different failures
Gas heaters depend on a burner, a thermocouple or igniter, and a vent that carries combustion gases outdoors. A blocked vent is a safety problem and the plumber checks it on every gas visit. Electric heaters depend on two elements and two thermostats, and a failed lower element is a classic cause of short hot showers.
Tankless units fail differently. Mineral scale clogs the heat exchanger, a fault code appears on the display, and the unit shuts down. The plumber reads the code, descales if the water supports it and replaces sensors. Our tankless water heater page covers service and installation.
Why Derry homes have particular heater problems
Homes in Derry, Londonderry and Salem that use town water see different scale patterns than homes on private wells in Hampstead and Chester. Well water often carries more iron or minerals, and those collect in the tank and on the elements. Owners on wells benefit from regular flushing. If you are unsure what your water contains, the New Hampshire health department recommends testing a private well at set intervals.
Cold basements add their own problem. A heater that sits in an unheated cellar works harder in January, and a vent pipe that runs through a cold space can collect condensation. The plumber looks at the room as well as the tank.
Before the plumber arrives
A few quick checks help the dispatcher, and one of them may restore hot water without a visit.
- Check that the electric heater's breaker has not tripped, and reset it once only.
- Look for the pilot light on a gas heater and note whether it is lit.
- Note the brand, size and age on the data plate.
- Clear boxes from around the heater so the plumber can work.
- Photograph any water on the floor for your insurer.
Water Heater Repair questions in Derry
Yes. The line is open 24/7. If the tank is leaking, close the cold water valve above it and switch off the power or gas, then call (603) 815-9179. A plumber can restore hot water the same day when parts are available.
Mineral sediment collects on the bottom of the tank and traps water that boils under it. Flushing may calm it. If the tank is old and heavily scaled, replacement can be the better answer.
It depends on the age, the part that failed and whether the tank is leaking. Small parts on a sound tank are worth repairing. A leaking tank is not repairable, and a repair that costs a large share of a new heater rarely pays back.
Leave the house, do not touch switches and call 911 or the gas utility from outside. Call us after the area is declared safe.
Yes, for many common faults such as scale, sensor errors and ignition problems. The plumber reads the error code, tests the unit and tells you whether repair or replacement makes sense.
References: follow the manufacturer's instructions for your heater, and the state plumbing code (part of the New Hampshire state building code). NH DHHS and NHDES publish private well testing advice.
Hot water back the same day when parts allow
Call any hour for water heater repair in Derry.