Case Study: No Hot Water in the Shower, Mableton, GA

Diagnosis and Approach

Justin Davis took the call while the homeowner was standing in the bathroom. Instead of immediately scheduling another visit, Justin asked the homeowner to look around the room and describe what he saw.

That is how the issue was found. Underneath the sink in the master bathroom sat a tempering valve.

A tempering valve blends cold water into a hot line to bring the temperature down. When one of these valves fails, it can let cold water cross over to the hot side. The water heater may still produce hot water correctly, but cold water joins the line before it reaches the fixture, so the shower never gets hot.

That explained why the earlier repairs failed. The symptoms pointed at the water heater and shower valve, but the actual failure sat between them. Justin identified it in a 10-minute phone conversation about a problem four other plumbers had already seen in person.

The Davis & Sons Plumbing Solution

The crew removed the tempering valve because it was not needed on that shower line.

A shower valve already has a tempering system built into it, called a scald guard, which helps keep water from getting hot enough to burn someone. Since the shower was already regulated at the fixture, the separate failed tempering valve was creating the problem instead of solving one.

This work fits within plumbing repair, the same service line that covers water pressure restoration, traditional and tankless water heater diagnostics, pipe leak detection, and clogged sink, shower, and toilet clearing. Repairs are performed by licensed, bonded, and background-checked technicians using code-compliant parts.

Services provided

• Phone diagnosis of the no hot water complaint
• Identification of the failed tempering valve under the master bathroom sink
• Removal of the failed tempering valve
• Restoration of hot water to the shower

Results and Outcome

• The homeowner had hot water in the shower for the first time since buying the home.
• The cause was identified in a 10-minute phone conversation, after four plumbing companies had looked at the issue on site.
• The final repair cost $295, compared with the almost $4,000 the homeowner had already been charged for work that did not fix the problem.
• The working fix was removing one failed valve, not replacing the water heater again or cutting out more plumbing.

Why This Job Matters

When a shower will not get hot, the water heater can look like the obvious suspect. This project showed why diagnosis matters before another major replacement is approved. A failed tempering valve can create the same symptom while the water heater itself works properly.

The difference in this job was not more equipment. It was asking the right questions, looking in the right place, and understanding how cold water could cross into the hot side of the system.

That standard is part of how Davis & Sons Plumbing has served homeowners since 1995. The company provides free virtual quotes by photo or FaceTime, offers guaranteed pricing within 15 minutes, and has every job overseen by a fully licensed and insured Master Plumber.

Repairs by Davis & Sons Plumbing are backed by a one-year workmanship warranty on labor, manufacturer warranties on parts, and the company’s plumbing service guarantee.

Ready to Finally Fix the Plumbing Problem? 

Dealing with a plumbing problem that has already survived one or two repairs? Request a free virtual quote or call (770) 943-8170 for help from Davis & Sons Plumbing.