Tankless Water Heater Repair & Installation in Lithia Springs, GA

When the shower runs strong on cold and weak on hot, the cause lies somewhere on the hot side of the house: the tankless water heater itself, the valves and filter around it, or the hot piping and fixtures beyond it. In Lithia Springs homes the fix can be anything from rinsing a small screen to descaling the unit or replacing a stretch of corroded pipe, so it pays to find the restriction before changing parts. For tank-style heaters and other options, see our Georgia water heater repair and installation overview.

Why some pressure loss is normal with tankless

Water has to travel through the heat exchanger, a set of narrow passages that carry it past the burner. That path costs some pressure, and the loss grows as flow increases. Many units also have a motorized flow control that throttles the water when the burner cannot heat the full flow to the set temperature, which happens most in winter, when water enters the house colder. A modest difference between hot and cold at a wide-open tap can therefore be normal. A sharp drop, or one that appeared suddenly, is not.

Common restrictions on the hot side

• A clogged inlet filter. Most units have a small screen at the cold inlet that traps grit and pipe debris, and it can load up quickly after water main work or plumbing repairs.
• A valve left partly closed. Isolation valves under the heater are sometimes not fully reopened after a flush or repair.
• Scale in the heat exchanger. Mineral buildup narrows the passages and often brings overheating codes with it.
• Fixture problems. A clogged aerator or showerhead, or a worn hot-side cartridge, restricts one tap without affecting the rest.
• Corroded or undersized piping. Old galvanized lines close up from the inside, and long runs of small pipe add friction that a tankless unit makes easier to notice.

Narrowing it down

1. Is the weak flow at every hot tap or just one? One tap points to the fixture; all of them point to the heater or the main hot line.
2. Has cold water weakened too? Then household pressure as a whole, and the pressure-reducing valve, become suspects.
3. Did it start suddenly, after a water outage or a repair? That points to debris in the filter or a valve position.
4. Does the heater report flow? Many models display a flow reading, so the technician can compare what the unit sees with what the tap delivers.

From there the work is hands-on: checking valve positions, pulling the inlet screen, measuring pressure and opening up a fixture if only one tap is affected.

Fixes, from simple to larger

A rinsed filter and a fully opened valve settle a surprising share of these calls. A scaled heat exchanger gets a descaling flush through the service ports. Aerators, showerheads and cartridges are cleaned or replaced through our faucet and valve repair service. When cold flow is low as well, a pressure test and a look at the regulator fall under water pressure and PRV service. If corroded piping is the restriction, replacing the affected hot lines restores flow that no amount of heater work can.

Permits for piping or heater replacement

Plumbing permits for Lithia Springs addresses come from Douglas County. The county's Building Permits and Inspections office handles them for new and renovation plumbing work, and under the county code they generally go to a plumber with a state master license or to a homeowner working on their own home. Either way, the permit comes before the pipe work starts.

Questions about weak hot water flow in Lithia Springs

Why is my hot water pressure lower than my cold water pressure?

With a tankless unit, a small difference is expected because water loses some pressure passing through the heat exchanger. A large or sudden gap usually means something is restricting the hot side: a clogged inlet filter, a partly closed valve, scale inside the heater, a blocked aerator or corroded hot piping. Whether every hot tap is affected, or only one, is the quickest first clue.

Does a tankless heater slow the water down in winter?

Many models do, on purpose. When incoming water is colder, the burner needs more heat to reach the set temperature, and a unit at its limit may throttle flow rather than send out lukewarm water. The effect shows most at high flows, such as a tub filling while a shower runs. If it happens with a single fixture open, the heater may be undersized or scaled and is worth checking.

Can I clean my tankless heater's inlet filter myself?

Many owner's manuals show how. The usual steps are to turn off power and gas, close the water valves, open a hot tap to relieve pressure, then unscrew and rinse the screen. Take care with the small seal around it, since a nicked O-ring can leak. If the screen is damaged, or flow does not improve afterward, the restriction is somewhere else.

What to tell us

Let us know which taps are affected, whether cold water is weak as well, when the change began and whether the water was shut off recently for any reason.

Alpha Plumbing and Sewer can trace where the hot water flow is being lost in your Lithia Springs home; the number is (404) 409-4448.