Hot Water Working But Not Radiators

Hot Water Working But Not Radiators: Troubleshooting Your Heating System

Having hot water but no heat from your radiators is a frustrating problem, leaving you shivering in a cold house. This issue, while seemingly simple, can stem from various sources within your central heating system. This guide will walk you through the common causes and troubleshooting steps to get your radiators pumping out warmth again.

Meta Description: Radiators cold but hot water working? This troubleshooting guide identifies common causes like airlocks, faulty pumps, thermostat issues, and more, helping you restore warmth to your home.

1. The Airlock Culprit: Trapped Air in Radiators

The most frequent culprit behind cold radiators despite a functioning hot water system is air trapped within the radiators themselves. Air, being less dense than water, sits at the highest point of the radiator, preventing hot water from circulating fully.

• Symptoms: Cold top of radiator, warm bottom. Gurgling or hissing sounds when you bleed the radiator.

• Solution: Bleeding your radiators is the first port of call. You'll need a radiator key (easily purchased from most hardware stores). Locate the bleed valve (usually a small valve at the top of the radiator). Place a container underneath to catch any escaping water. Slowly turn the valve anticlockwise using the key until you hear a hissing sound and water starts to escape, carrying the air with it. Tighten the valve once a steady stream of hot water emerges. Repeat this for all cold radiators.

2. The Pump Problem: A Faulty Circulation Pump

Your central heating system relies on a circulation pump to move the heated water through your pipes and radiators. A malfunctioning pump means no, or insufficient, water flow.

• Symptoms: Cold radiators throughout the house. You might hear unusual noises from the pump (grinding or humming) or notice it's not spinning.

• Solution: Listen carefully near the pump. If it sounds faulty, or you suspect a problem, it's best to call a qualified heating engineer. Attempting DIY repairs on the pump is risky and could worsen the situation.

3. Thermostat Troubles: Incorrect Settings or Malfunction

A faulty or incorrectly set thermostat can prevent your heating system from turning on, or limit the flow of hot water to your radiators.

• Symptoms: Radiators consistently cold, regardless of the thermostat setting. The thermostat itself might not be displaying correctly or responding to changes.

• Solution: Check the thermostat settings. Ensure it's set to "on" and the temperature is adequately high. If the problem persists, the thermostat itself may require replacement or professional servicing.

4. System Pressure Issues: Low Water Pressure in the System

Insufficient water pressure within the central heating system will hinder hot water circulation to your radiators.

• Symptoms: Cold radiators, or some radiators cold while others are warm. A pressure gauge, usually located on your boiler, may show a low reading.

• Solution: Consult your boiler's manual for instructions on topping up the water pressure. If the pressure remains low despite topping it up, there may be a leak within the system requiring professional attention.

5. Blocked Pipes or Valves: Obstructions Hindering Water Flow

Blockages in your pipes or partially closed valves can restrict or completely stop the flow of hot water to your radiators.

• Symptoms: Some radiators cold, others warm. This problem often affects only certain parts of the house.

• Solution: Check all valves leading to the cold radiators, ensuring they're fully open. If a blockage is suspected, this requires professional investigation and potentially pipe clearing.

6. Boiler Issues: Problems with the Heat Source

While you have hot water, issues with your boiler, such as a faulty heat exchanger or low gas pressure, could impact the system's ability to heat the water sufficiently for effective radiator function.

• Symptoms: Lukewarm radiators even after bleeding and other checks.

• Solution: This usually requires professional boiler servicing or repair. Only a qualified engineer should attempt boiler repairs.

Taking Action: When to Call a Professional

If you've tried the above steps and still have cold radiators despite having hot water, it's crucial to call a qualified heating engineer. They possess the expertise and tools to diagnose and resolve more complex issues, preventing further damage or risks to your system. Ignoring the problem can lead to costly repairs in the long run. Remember, safety should always be a priority.