There are two parts to the boiler, the Hot Water Supply Side and the Hot Water Return Side. When the boiler stops working, so does the heat! The boiler may be producing insufficient heat or heating inconsistently or irregularly. The cause of improper heating may also be in the expansion tank. Are you looking for emergency boiler repair london? Then we are here to help you. Our experts and professionals provide the best services to you. For more information, visit our website.