Water System Problems

Cash Acme 3/4 Inch RV FWL-2 Pressure Relief Valve, Bronze, 75 PSI, 14917-0075

Camco 10471/10473 RV 3/4-Inch Temperature and Pressure Relief Valve with 4-Inch Probe

Watts 0342691 30 PSI Pressure Relief Valve, Bronze, 3/4",‎0.75 Inch 335 M2-030

LANCHEZ 1.6 HP Shallow Well Pump with Pressure Tank, 1340 GPH Automatic Irrigation Water Booster Jet Pump, 115V Stainless Steel

The Most Common Reasons Relief Valves Drip
1. Excessive Incoming Water Pressure

High supply pressure is the single most common cause. When cold water enters the heater already above safe pressure, heating it expands the water and pushes pressure past the valve threshold.

This often goes unnoticed because fixtures still “work fine.”

2. Thermal Expansion in a Closed System

Modern plumbing systems often include:

Pressure-reducing valves
Check valves
Backflow preventers

These devices prevent expanded hot water from pushing back into the supply. The pressure has nowhere to go — except out the relief valve.

3. Failed or Waterlogged Expansion Tank

Expansion tanks absorb pressure created during heating cycles. If the internal bladder fails or the tank is improperly charged, pressure spikes reach the relief valve.

## Top Pressure Tank Picks

1.5HP Shallow Well Pump with Pressure Tank, 1340GPH Irrigation Jet Pump, 164FT 115V Automatic Water Pumps Booster System

Red Lion RL14A - 14-Gallon Vertical Pre-Charged Pressure Tank with Thermoplastic Base for Well Pumps, 1-Inch FNPT Elbow System Connection, Almond, 604687

Red Lion RL20A - 20-Gallon Vertical Pre-Charged Pressure Tank with Thermoplastic Base for Well Pumps, 1-Inch FNPT Elbow System Connection, Almond, 604682

MEASUREMAN 2-1/2" Water Pressure Test Gauge, 3/4" Female Hose Thread, 0-200 psi/kpa with Maximum Pressure Memory

4. Faulty or Aged Relief Valve

Relief valves do wear out over time. Mineral buildup, corrosion, or repeated activation can prevent proper reseating.

However, replacing the valve without fixing the pressure issue will cause the new valve to drip as well.

Step-by-Step Diagnosis (Do This in Order)
Step 1: Measure Static Water Pressure

Attach a pressure tester to a hose bib or laundry tap and measure pressure with no water running.

## Top Water Pressure Tester Picks

Pressure Gauge,Glycerin Liquid Filled,2" Dual Scale Dia,0-600 psi/bar/kpa,1/4" NPT Male Brass Connection,Lower Mount, Stainless Steel Case

MEASUREMAN Water Pressure Gauge, 0-200 PSI Water Pressure Tester with 2-1/2 Inch Dial & Durable 3/4 Inch Hose Thread, Ideal for Home

Pronese Stainless Steel Water Test Pressure Gauge Kit 2" Dial Size,Gauge+12" EPDM Rubber+1/4" LF Valve+1/4 to 3/4 Adapter

Water Pressure Regulator, Brass Lead-Free Water Pressure Reducer Kit, Adjustable Valve with Inlet Screened Filter

40–60 PSI → normal
60–80 PSI → elevated
Above 80 PSI → unsafe

If pressure exceeds 80 PSI, address this first.

Step 2: Check for Pressure Creep

Leave the gauge attached for several hours. If pressure rises significantly without water use, thermal expansion or regulator failure is present.

Step 3: Inspect the Expansion Tank

With water pressure relieved:

Tap the tank — it should sound hollow at the top
Check air charge matches system pressure
Water at the air valve indicates bladder failure

Step 4: Evaluate the Relief Valve Itself

If pressure and expansion are controlled but dripping continues, the valve may be fouled or worn.

Replacement is appropriate only after system issues are corrected.

How to Fix the Problem Correctly
Install or Replace a Pressure Regulator

If incoming pressure is too high, a pressure-reducing valve (PRV) is required to protect the entire system.

## Top Pressure Regulator Picks

Water Pressure Regulator with Colorful Gauge, Hand Adjustable Knob,Brass Lead-Free Water Pressure Reducer with Inlet Screen Filter

Wilkins 12-NR3XL 1/2" Pressure Reducing Valve

Handle Adjustable RV Water Pressure Regulator Valve, Upgraded Brass Lead-Free RV Water Pressure Reducer with Gauge, 3/4” NH Thread

LANCHEZ 1.6 HP Shallow Well Pump with Pressure Tank, 1340 GPH Automatic Irrigation Water Booster Jet Pump, 115V Stainless Steel

Install or Recharge an Expansion Tank

Expansion tanks must be sized and charged correctly. This single component often eliminates relief valve discharge entirely.

## Top Pressure Tank Picks

1.5HP Shallow Well Pump with Pressure Tank, 1340GPH Irrigation Jet Pump, 164FT 115V Automatic Water Pumps Booster System

Red Lion RL14A - 14-Gallon Vertical Pre-Charged Pressure Tank with Thermoplastic Base for Well Pumps, 1-Inch FNPT Elbow System Connection, Almond, 604687

Red Lion RL20A - 20-Gallon Vertical Pre-Charged Pressure Tank with Thermoplastic Base for Well Pumps, 1-Inch FNPT Elbow System Connection, Almond, 604682

ThermoMate 3/4 Inch IPS Isolator Tankless Water Heater Service Valve Kit, with Pressure Relief Valve, Clean Brass

Replace the Relief Valve (Only After Fixing Pressure)

If the valve continues to drip after pressure is controlled, replacement is appropriate.

Never cap, plug, or modify the discharge line.

## Top Pressure Relief Valve Picks

Cash Acme 3/4 Inch RV FWL-2 Pressure Relief Valve, Bronze, 75 PSI, 14917-0075

Camco 10471/10473 RV 3/4-Inch Temperature and Pressure Relief Valve with 4-Inch Probe

Watts 0342691 30 PSI Pressure Relief Valve, Bronze, 3/4",‎0.75 Inch 335 M2-030

GoveeLife Water Leak Detector with 105dB Adjustable Alarm, Water Alarm with Dual Sets Sensor Probes Leaks and Floods

What NOT to Do (Critical Safety)

Do not cap or plug a relief valve
Do not reduce discharge pipe size
Do not ignore repeated discharge

These actions can lead to catastrophic tank failure.

When to Call a Professional

If pressure exceeds 100 PSI
If the water heater overheats
If you are unsure how to safely depressurize the system

Preventing Future Relief Valve Issues

Test system pressure annually
Replace aging PRVs proactively
Check expansion tank charge yearly

## Top Leak Detector Picks

Flood Buzz Small Water Leak Alarm 3-Pack | Ready to Use Right Out of The Box, No Setup Required

THIRDREALITY Zigbee Water Leak Sensor with Dripping Detection 4 Pack, 120 dB Alarm, App Notifications Enabled When Compatible with Home Assistant

YoLink Smart Home Leak Detection Starter Kit – Hub + 4 Water Leak Sensors (0 dB), LoRa Long-Range, Alexa & IFTTT Compatible