Our 24/7 line is open now if your water heater is leaking or you have no hot water at all. If water is spreading from the tank, shut the cold supply valve above the heater and turn its power off at the breaker. Keep people and pets away from wet floors near any outlet.
If a gas odor is present, leave the building and call 911 and your gas utility before you call us.
Do not open the drain valve on a hot tank to see what happens. The water inside can scald, and a tank under pressure is not a good place to experiment.
When a water heater leak is an emergency
Not every drip needs a midnight call, but some do. Water coming from the tank body, steady dripping from the relief valve pipe, or a wet floor that grows overnight deserves a same-day look. A leak from a loose fitting or a worn valve is often repairable, while a leak from the tank shell itself usually is not.
If the unit sits in a closet, garage or above living space, water travels quickly into drywall and flooring. We would rather you call early and turn the water off than wait to see whether it stops. Tell us the heater type, its approximate age and where the water is showing up, and we can plan the visit around it.
No hot water: what is usually behind it
Different heaters fail in different ways, and a few symptoms are easy to mix up. Here is what we check first.
Gas heater with no heat
A pilot that will not stay lit, a failed thermocouple or flame sensor, or a dirty burner can all leave you cold. These are often repairable parts, and the age of the tank decides whether it is worth fitting them.
Electric heater with no heat
Electric tanks rely on two heating elements and thermostats. A failed element or a tripped limit switch will leave you with lukewarm or cold water, and both are usually inexpensive parts.
Hot water that runs out fast
When the shower goes cold quickly, a lower element may have failed, or sediment has built up on the tank floor and is taking up room. A flush sometimes restores the supply, and a look at the burner or element tells us which.
Heat pump unit showing a fault
Hybrid and heat pump water heaters add a compressor, fan and condensate line to the usual tank. A blocked condensate drain, restricted airflow or a control fault can stop heat, and a quick check often finds it.
Water too hot or not hot enough
A thermostat set wrong, a failed mixing valve or a crossed connection can all give odd temperatures. These are different problems with different fixes, so we test before we replace anything.
How we diagnose and repair
We keep it simple and we show you the fault before we fix it.
Make it safe
We check for water, gas smell and electrical risk first. If the tank is leaking badly we shut the supplies and stop the water before anything else.
Find the real fault
We test the thermostat, element or burner, the relief valve and the connections, and we look at the tank for corrosion at the base and fittings. A leak at a fitting and a leak from the tank wall are very different jobs.
Tell you the options
If a part will fix it, we say so and price it. If the tank has failed or the repair would cost more than it is worth, we explain why and offer water heater replacement as the next step.
Repair and test
We fit the part, restore power or gas, and confirm the heater reaches temperature with no leaks. We also check that the relief valve discharge pipe is in place and that the seismic strapping is intact.
Millbrae water and your heater
Millbrae's water comes entirely from the San Francisco Regional Water System, which is mostly Hetch Hetchy water. The 2025 water quality report lists hardness between 8.1 and 112 ppm with an average of 62 ppm, which is on the soft side by common standards. For a tank that means scale is a slower problem here than in hard water towns, but sediment still collects over the years and is worth flushing.
The same report confirms the water is disinfected with chloramine. We mention it because it is part of what flows through your heater every day, and we can talk through what that means for your particular tank and fittings if you are weighing a repair against a new unit.
California law also requires that water heaters be braced, anchored or strapped against earthquake movement, under Health and Safety Code section 19211. If we open up the heater area and find loose or missing straps, we will point it out and offer to correct it. The San Andreas Fault lies within a mile of the western edge of the city, so this is a practical safeguard and not a formality.
Repair or replace: how to decide
The honest answer depends on age, location of the leak, and what else is failing. This table shows how we usually weigh it.
| Situation | Usually | Reason |
|---|---|---|
| Failed thermostat, element or thermocouple | Repair | Small part, tank is otherwise sound |
| Leak at a fitting, valve or relief pipe | Repair | Connection can be redone or the valve swapped |
| Water seeping from the tank shell | Replace | Corrosion inside cannot be repaired |
| Older tank with repeated repairs | Often replace | Further parts treat symptoms, not the age |
| Heat pump unit with a control fault | Repair first | Parts and settings are often the cause |
Things homeowners try and what we do differently
DIY or what people try
- Relight a gas pilot repeatedly without finding out why it went out
- Turn the thermostat to its highest setting to chase hot water
- Ignore a damp patch under the tank until the floor softens
- Drain the tank with the power still on, which can burn out an electric element
- Cap or plug the relief valve pipe to stop a drip
Professional approach
- Test the part that actually failed before ordering anything
- Check the thermostat range and mixing valve for scald risk
- Look at the tank base and fittings for the source of moisture
- Switch off power or gas, then drain and flush properly
- Leave the relief valve and its discharge pipe clear so pressure can escape safely
What affects the cost of water heater repair
We explain what we found and what it would take, and you approve the work before we start.
Which part failed
A thermostat or element is a smaller job than a gas control valve or a heat pump component.
Type of heater
Gas, electric and heat pump units use different parts and take different time to service.
Access
A heater in an attic or tight closet takes more effort to reach than one in a garage.
Age of the tank
An older unit may be worth fewer repair dollars than a newer one.
Time of day
Nights and weekends can affect pricing, and we say so before dispatch.
Call the 24/7 line for a clear price before work starts. If a repair is not worth doing, we tell you and discuss the alternative rather than fitting a part that will not last.
Cold water or a wet floor?
Describe what you see and the type of heater you have, and we will advise you on the best next step. The call line is answered overnight and on weekends.
Related water heater work
Some heaters are worth repairing and some are not. If yours is near the end, our water heater installation page explains how a planned swap works, and the tankless water heater page covers on-demand units, including how they differ from a tank.
For service outside Millbrae, see our Burlingame plumbing page, and the service area page lists the wider coverage.
Yes. The 24/7 line is answered overnight, on weekends and on holidays. If water is spreading or you have no hot water, call and describe the problem. We dispatch as soon as a technician is available and we give you a price before work starts, without promising a specific arrival time.
It depends on where the water comes from. A leak from a fitting, valve or relief pipe can usually be repaired. A leak from the tank shell is caused by internal corrosion, and the tank has to be replaced.
On a gas unit it is often a failed pilot, thermocouple or burner. On an electric unit it is usually a heating element or thermostat. We test the part before replacing anything, so you pay only for what has failed.
A small drip at a fitting may be safe for a short time if you shut the supply, but a leak from the tank can worsen quickly. Turn off the power or gas and the cold supply valve, then call us.
Leave the building at once and call 911 and your gas utility from outside. Do not turn lights or switches on or off. Call us only after the utility confirms it is safe.
Yes. Hybrid and heat pump units have a compressor, fan and condensate line besides the tank, and faults are often in the controls or airflow. We check those first and tell you plainly if the unit needs more than a repair.
Yes. Call the 24/7 line and we explain the fault and give a clear price before we begin. If we find something that changes the job, we stop and talk it through with you first.
Sources and standards: California Health and Safety Code section 19211 on water heater bracing. The California Plumbing Code (based on the Uniform Plumbing Code). The California Contractors State License Board (CSLB) C-36 plumbing classification.