Water heater repair is urgent when the tank is leaking, when the burner will not light in cold weather, or when the house has no hot water at all. Our 24/7 line answers at night and on weekends, and we send a licensed plumber the same day when the schedule allows.
While you wait, close the cold water valve on top of the heater and switch off its power or gas control. If water is spreading, turn off the main water valve and keep the electric panel dry. If you smell gas, leave the house and call the gas utility or 911 before you call us.
No hot water: the usual causes
Callers describe this one in plain terms. The shower runs cold, the dishwasher never gets hot, or the water is warm for two minutes and then fades. Each symptom points to a different part.
| What you notice | Likely cause | Typical repair |
|---|---|---|
| No hot water at all, electric heater | Failed heating element or tripped high-limit switch | Test and replace the element or reset the switch |
| No hot water, gas heater | Pilot out, bad thermocouple or failed gas control | Relight, replace thermocouple or control valve |
| Hot water fades after a few minutes | Broken dip tube or one dead element | Replace the dip tube or the lower element |
| Water is lukewarm | Thermostat set low, sediment on the elements | Adjust thermostat, flush the tank |
| Rumbling or popping noise | Sediment hardened on the tank bottom | Flush, or plan a replacement if the tank is old |
We confirm the cause with a meter or a gas test before we replace anything. If the part is cheap and the tank is sound, we repair it. If the tank itself has failed, we say so.
A leaking water heater: what to do first
Leaks are the most common reason people call us about water heaters. The water may come from the tank, from a fitting on top, from the relief valve or from a nearby pipe that only looks like the heater.
- Shut off the supplyClose the cold water inlet valve above the heater. Turn off the electric breaker or set the gas control to off.
- Find the sourceDry the area and watch where the first drop forms. Water at a pipe joint or valve is often repairable.
- Protect the floorMove stored items, lay towels and use a wet vacuum on standing water. A garage slab or basement floor drain will carry the rest.
- Call the 24/7 lineTell the dispatcher the tank size, the fuel and where the water is coming from.
A tank that leaks from its body cannot be patched. The steel liner has corroded through, and a replacement is the safe answer. Our water heater replacement page explains that process, and a heater that failed at 2 a.m. is usually swapped the same day.
Pilot lights, thermocouples and burner problems
A gas heater that keeps going out usually has a worn thermocouple, a dirty pilot orifice or a draft problem in the vent. We clean, test and replace those parts, and we check that exhaust leaves the house properly.
If you smell gas or the heater smells of burnt dust and soot, stop and ventilate. Gas heaters produce carbon monoxide when poorly vented, so a working carbon monoxide alarm near the sleeping area matters.
Please do not relight a pilot that keeps failing. A repeat failure tells us something else is wrong, and a plumber should check it.
Electric, gas and heat pump models
Electric heaters fail at the elements and thermostats. Gas heaters fail at the pilot, burner and gas control. Heat pump water heaters add a compressor and a condensate drain, and their error codes point to specific faults.
We repair all three types when parts are available. We also tell you when a repair costs more than the heater is worth, which is common on tanks past 10 years old. If you are weighing a switch to a tankless water heater, we explain the trade-offs before you decide.
Tankless units and the flush they need
Tankless heaters fail differently. Error codes, bursts of cold water and reduced flow often trace to scale inside the heat exchanger. A flush and descale restores the flow in many cases, and homes on private wells may need it more often. Test your tap water and ask your water utility for its annual quality report to judge how hard your water is.
Why water heaters fail in Londonderry homes
New Hampshire winters push heaters hard. Incoming water is very cold, and a tank in an unheated garage or basement works longer to keep up. Pipes near an exterior wall can also freeze and split, and a leak at the heater may start there.
Many Londonderry homes use private wells, and well water carries minerals and sediment into the tank. The state environmental agency offers programs for well testing, and a water test also tells us whether a filter or a flush schedule makes sense. Sediment is the most common reason tanks fail early.
What water heater repair costs
A repair price comes before we touch the element, valve or burner. These factors set it:
- The part that failed, such as an element, thermocouple, valve or gas control.
- The fuel type and the model, since parts for some brands take longer to find.
- Whether the tank can be saved or a replacement is the sounder choice.
- Access, venting and code updates needed when the work is done.
- After-hours, weekend or holiday dispatch.
Homeowners policies often cover sudden water damage from a failed tank but not the heater itself. Check with your agent, and photograph the damage before you clean up. For your own number, call (603) 815-9179.
Where we repair water heaters
We serve all of Londonderry, from North Londonderry to Wilson and the Woodmont Commons area. We also dispatch to Derry, Hudson and Windham. When water has already reached walls or ceilings, our leak detection team can trace where it went.
Relief valves and discharge piping are code items under the International Plumbing Code (IPC), so we check them whenever we open a water heater.
Questions we hear in Londonderry
Yes. A leaking tank or a cold shower at midnight is a fair reason to call (603) 815-9179. Describe the leak or the missing hot water, and we book the same day when we can.
If the water comes from the tank body, no. The liner has failed and the tank needs replacement. If it comes from a fitting, valve or drain, we can often repair it.
Electric units usually have a failed element or tripped limit switch. Gas units usually have a pilot or thermocouple fault. A broken dip tube also sends cold water to your taps.
It depends on age, condition and the repair. A new element on a sound tank is worth it. Repeated repairs on a tank past 10 years usually are not.
Sediment hardens at the bottom and traps steam bubbles under it. A flush may clear it. If the tank is old, the noise may signal that replacement is near.
Yes. We clear error codes, flush scale from the heat exchanger and replace failed sensors or valves when parts are available.