How to Fix a Boiler with No Hot Water

Overview

A boiler with no hot water is a frustrating problem. This guide covers diagnosing and fixing common causes.

Step-by-Step Fix

1. Firstly, ensure your thermostat is set to a temperature high enough for hot water production, typically above 60°C for the hot water setting. Confirm the thermostat isn't on a 'frost protection' or 'off' setting, as this will prevent the boiler from firing up for hot water.
2. Next, verify that your boiler's programmer or timer is set correctly for hot water to be active. Check if it's currently within a scheduled 'on' period for hot water or if it's set to 'always on' for heating hot water.
3. Then, locate the pressure gauge on the front of your boiler and check if the needle is within the recommended operating range, usually between 1 and 1.5 bar. If the pressure is too low, you may need to repressurise the system according to your boiler's manual, but be cautious not to overfill.
4. If your boiler has a pilot light, visually check to see if it is lit; you might need to look through a small viewing window. If the pilot light is out, consult your boiler's manual for instructions on how to safely relight it, as specific procedures vary by model.
5. If your boiler has a diverter valve, which directs hot water to either your taps or radiators, it may be stuck or faulty. You won't be able to easily check or fix this yourself, but listen for any unusual noises coming from the boiler that might indicate a problem with this internal component.
6. If you have followed these steps and are still experiencing no hot water, or if you suspect a more complex internal fault, it is crucial to contact a Gas Safe registered engineer immediately. Do not attempt further DIY repairs on gas appliances, as this is unsafe and illegal.

Common Symptoms & Diagnostic Resolutions

Review the common error codes and operating symptoms below to quickly identify the root cause of the fault before ordering replacement parts.

Frequently Asked Questions