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Boiler Repair

Troubleshooting Guide: Hot Water but No Heating? Here’s How to Diagnose the Problem

If you have hot water coming from your taps but no heating from your radiators, it can be a frustrating and confusing situation. As a leading provider of boiler cover and repair services in Edinburgh, we understand the importance of a properly functioning heating system, especially during the cold winter months. In this troubleshooting guide, we’ll walk you through the steps to diagnose the problem and get your central heating back up and running.

Check Your Boiler Pressure

One of the most common causes of hot water but no heating is low boiler pressure. Your heating system relies on the correct pressure to circulate hot water through the radiators. If the pressure drops too low, the system may fail to function properly.

To check your boiler’s pressure, locate the pressure gauge on the control panel. In most cases, the ideal pressure should be between 1 and 1.5 bar. If the needle is below this range, you’ll need to repressurise your boiler. Consult your boiler manual for specific instructions on how to do this safely.

Inspect the Diverter Valve

If your boiler pressure is within the normal range, the next step is to check the diverter valve. In combi boilers, the diverter valve is responsible for switching between providing hot water and central heating. If this valve becomes stuck or faulty, it can cause issues with your heating while still allowing hot water to flow from your taps.

To determine if the diverter valve is the culprit, turn on your central heating and feel the pipes connected to your boiler. If the pipe leading to the hot water taps is warm but the pipe leading to the radiators is cold, it’s likely that the diverter valve is stuck.

Look for Frozen Condensate Pipes

During cold weather, the condensate pipe that carries wastewater away from your boiler can freeze, causing a blockage. This can prevent your boiler from functioning properly, resulting in hot water but no heating.

To check for a frozen condensate pipe, locate the plastic pipe that runs from your boiler to an external drain. If you notice ice or frost on the pipe, it’s likely frozen. You can try thawing it out using warm water or a heat pad. If the problem persists, contact a professional heating engineer for assistance.

Check Your Thermostat Settings

Sometimes, the solution to your heating problem can be as simple as adjusting your thermostat settings. Make sure your thermostat is set to “heat” mode and that the temperature is set higher than the current room temperature. If you have a programmable thermostat, ensure that it’s set to the correct time and day.

If your thermostat seems to be working correctly, but your radiators remain cold, there may be an issue with the wiring or the thermostat itself. In this case, it’s best to consult a gas-safe registered engineer for further diagnosis and repair.

Bleed Your Radiators

If you notice cold spots on your radiators or they’re not heating up evenly, there may be trapped air in the system. This can prevent hot water from circulating properly, leading to poor heating performance.

To remove trapped air, you’ll need to bleed your radiators. Start by turning off your heating system and allowing the radiators to cool. Then, using a radiator key, slowly open the valve at the top of each radiator until you hear a hissing sound. This indicates that air is escaping. Once the water starts to drip from the valve, close it tightly and move on to the next radiator.

Check for Sludge Build-Up

Over time, sludge and debris can accumulate in your heating system, restricting water flow and reducing the efficiency of your radiators. If you have an older system that hasn’t been regularly maintained, sludge build-up could be the reason for your heating problems.

Cold radiators, noisy pipes, and discoloured water when bleeding radiators are signs of sludge build-up. To remove sludge, you’ll need to perform a power flush, which involves forcing a high-pressure water and chemical mixture through your heating system to clear out any blockages. This is a job best left to a professional heating engineer.

Inspect the Motorised Valve

If you have a conventional heating system with a separate hot water cylinder, there will be a motorised valve that controls the flow of water between the boiler, radiators, and hot water cylinder. If this valve becomes faulty, it can cause issues with your heating.

To check the motorised valve, turn on your heating and hot water and listen for a clicking sound coming from the valve. If you don’t hear a click, the valve may be stuck or faulty. A heating engineer can diagnose and replace the valve if necessary.

Check the Pilot Light or Ignition System

If your boiler relies on a pilot light or electronic ignition system, a fault in these components can prevent your heating from working while still allowing hot water to function. If you have an older boiler with a pilot light, check to see if the flame is lit. If it’s out, follow the instructions in your boiler’s manual to relight it safely.

For modern boilers with electronic ignition, you may need to consult a gas-safe registered engineer to diagnose and fix any issues with the ignition system.

Consider the Age of Your Boiler

If your boiler is more than 10-15 years old and you’re experiencing frequent issues with your heating and hot water, it may be time to consider replacing it with a new, more efficient model. Older boilers can be less reliable and more prone to breakdowns, leading to higher repair costs over time.

Investing in a new boiler not only ensures a more reliable heating and hot water supply but can also help you save money on energy bills in the long run. Modern boilers are designed to be more energy-efficient, meaning they use less fuel to heat your home and water.

Importance of Regular Boiler Maintenance

To help prevent issues like hot water but no heating, it’s essential to schedule regular maintenance for your boiler and heating system. An annual boiler service performed by a gas-safe registered engineer can identify and fix potential problems before they lead to breakdowns or costly repairs.

At The Edinburgh Boiler Cover Company, we offer comprehensive boiler cover plans that include an annual boiler service and safety check, as well as access to our team of experienced local heating engineers in case of breakdowns or emergencies. Our plans start from just £19 per month, providing peace of mind and protection for your heating and hot water system.

When to Call a Professional Heating Engineer

While some heating issues can be resolved with simple troubleshooting steps, others require the expertise of a qualified heating engineer. If you’ve tried the above solutions and your heating still isn’t working, or if you’re unsure about how to diagnose or fix the problem safely, it’s time to call in the professionals.

At The Edinburgh Boiler Cover Company, our team of gas-safe registered engineers are equipped to handle all types of boiler and heating system issues. Whether you need a repair, replacement, or just some expert advice, we’re here to help.

To book a repair or learn more about our boiler cover plans, visit our website or give us a call today. Don’t let heating problems leave you in the cold – trust The Edinburgh Boiler Cover Company for all your heating needs.