When your boiler hot water, the system that delivers heated water for taps, showers, and radiators in your home. Also known as central heating hot water supply, it’s one of the most relied-on parts of your house — and when it fails, you notice fast. It’s not just about cold showers. If your boiler isn’t delivering hot water, something’s wrong inside the system — and it’s rarely as simple as turning a knob back on.
Most boiler hot water problems come down to a few key parts: the heat exchanger, the component that transfers heat from the boiler to your water, a failing circulation pump, the motor that pushes hot water through your pipes, or low system pressure. You might hear gurgling, see a pressure gauge reading below 1 bar, or notice that only your kitchen tap has hot water while the bathroom stays cold. These aren’t random glitches — they’re signals. A 10-year-old boiler is more likely to have a corroded heat exchanger, while newer models often fail due to faulty thermostats or blocked filters. If your boiler runs fine for heating but gives no hot water, it’s usually a diverter valve issue — this tiny part decides whether heat goes to radiators or taps, and it gets stuck more often than you’d think.
Before you call a technician, check your boiler’s pressure gauge. If it’s below 1 bar, topping it up might fix everything. Reset the boiler using the manual reset button — most models have one. If you still get no hot water, look for leaks around the pipes or radiator valves. Rusty water? That’s a sign of internal corrosion. Strange noises like banging or whistling? Could be limescale buildup. These are all clues. You don’t need to be a plumber to spot them. And if you’ve tried the basics and nothing works, it’s time to call someone who knows what’s inside your boiler. The posts below cover exactly that: real fixes for real problems, from DIY checks to knowing when replacement makes more sense than repair. Whether your boiler’s 5 years old or 15, you’ll find answers that match your situation.
A broken boiler usually means no hot water because the same system heats your home and your taps. Learn why this happens, when there are exceptions, and what to do next to stay safe and warm.
