A leaking hot water pressure relief valve is one of the most common issues faced by homeowners, especially those with older or low pressure hot water cylinders in Hamilton. While it may seem like a small leak, it can signal a larger issue with your hot water system and lead to water wastage, increased energy bills, or even structural damage if left unchecked.
This guide will walk you through how to fix a leaking pressure relief valve, explain what causes the leak, and when to call in professional plumbing services for help.
Understanding the Pressure Relief Valve
A pressure relief valve is a critical safety feature of your hot water system. Its purpose is to release water when the pressure or temperature inside the cylinder gets too high. This prevents the cylinder from bursting or being damaged due to excess pressure.
If you’re using a low pressure hot water cylinder, your valve may release water more frequently due to the way the system operates under lower pressure thresholds. However, consistent dripping or leaking from the valve is not normal and should be investigated.
Common Causes of a Leaking Pressure Relief Valve
Before attempting a fix, it’s essential to understand the possible reasons for the leak. Here are the most common causes:
1. Normal Thermal Expansion
Some dripping is normal when the water is heating, as the valve releases excess pressure due to thermal expansion. However, this should only happen briefly and not continuously.
2. Faulty Valve
Over time, mineral buildup, corrosion, or wear and tear can cause the valve to malfunction. This is especially true in older low pressure hot water cylinder systems.
3. Excessive System Pressure
If the system pressure is consistently too high, it can cause the valve to release water frequently. This might indicate a problem with the thermostat or pressure regulator.
4. Improper Installation
If the valve wasn’t installed correctly or the wrong type was used, it may not function as intended, leading to constant leaking.
Step-by-Step Guide to Fixing a Leaking Hot Water Pressure Relief Valve
If you’re confident working with basic plumbing and safety procedures, you may be able to replace the valve yourself. However, if you’re unsure, it’s always best to contact professional plumbing services.
Step 1: Turn Off the Power and Water Supply
- If you have an electric hot water system, switch it off at the circuit breaker.
- For gas systems, turn off the gas supply.
- Turn off the cold water inlet valve to the hot water cylinder.
Step 2: Drain Some Water
- Open a hot tap in the house to release pressure.
- Use the drain valve on the cylinder to release enough water to lower the level below the pressure relief valve.
Step 3: Remove the Old Valve
- Use a wrench to carefully unscrew the valve from the cylinder.
- Be cautious, as it may still be hot or release residual pressure.
Step 4: Clean the Thread
- Wipe away any debris or scale from the threaded connection on the cylinder.
- This helps ensure a tight seal with the new valve.
Step 5: Install the New Valve
- Apply thread seal tape to the new valve’s threads.
- Carefully screw it into place and tighten it firmly, but not excessively.
Step 6: Restore Water and Power
- Turn the cold water inlet back on slowly.
- Check for any leaks around the new valve.
- Once everything is sealed and secure, turn the power or gas supply back on.
When to Call Professional Plumbing Services
While some homeowners are comfortable with small plumbing tasks, others may prefer the assurance of hiring a professional. You should consider calling plumbing services if:
- The valve continues to leak even after replacement.
- You’re unsure about system pressure issues.
- You suspect corrosion or damage to the hot water cylinder.
- You’re dealing with a gas hot water system, which requires qualified handling.
Professional plumbers can quickly diagnose if the issue lies with the low pressure hot water cylinder pressure relief valve, or if there’s a deeper problem in the plumbing system.
Preventing Future Leaks
Routine maintenance is key to avoiding pressure relief valve issues in the future. Here are some preventive tips:
1. Test the Valve Regularly
Lift the test lever on the valve every six months to ensure it operates smoothly. Water should flow out when lifted and stop when released.
2. Check for Sediment Build-Up
Minerals in water can cause blockages. Consider draining and flushing your hot water cylinder once a year.
3. Monitor System Pressure
If you have consistently high or low pressure, your plumbing system may need adjustment. Install a pressure-reducing valve if needed.
4. Use Licensed Plumbing Services
Have your system inspected annually by a qualified plumber. They can catch minor issues before they become costly problems.
Cost Considerations
The cost to replace a low pressure hot water cylinder pressure relief valve in New Zealand typically ranges from $100 to $250, depending on the type of valve and service callout fees. While it might seem like an unnecessary expense, timely repairs can prevent much more costly damage down the track.
Final Thoughts
A leaking pressure relief valve shouldn’t be ignored. While it may start as a small drip, it can quickly escalate into a major problem affecting your entire hot water system. For homeowners with a low pressure hot water cylinder, being vigilant about valve maintenance is crucial. And if you ever feel out of your depth, don’t hesitate to contact professional plumbing services—your hot water system’s safety and efficiency are worth it.
