With boilers gaining popularity over the past two decades, it is a common trend now to heat water in this device. But, what if you have hot water but no heating? Worry not – you are not alone to face such annoyance!

Although the boiler is held the main suspect, fault in the surrounding components such as the thermostat, radiators, valves, cannot be understated. Give a quick read to this blog – it will help you manage the issue better.

Common causes for the issue

• Jammed radiators
• Ignition problems
• Blocking of boiler’s burner
• Broken motor valve
• Malfunctioning of circulation pump

What to do if you get hot water without heating?

Nowadays, almost every household uses the modern complex heating system. And if by any chance your water happens to boil without the heater’s help, it may leave you clueless and stranded.

To avoid such trouble, it is crucial to understand the general mechanism first. A standard central heater circulates hot water down through the pipes to radiators. The heat is transferred to the surrounding rooms, with the thermostat controlling the desired temperature.

Now, let’s delve into the issue!

In case your central heating system does not function, there might be potential issues in the motor valve. It may be broken, even. However, for a combi boiler, you must first check the usage settings through the boiler’s control panel.

Coming to radiators; even if one of them feels warmer than the rest; give bail to the ‘boiler’.  In such a scenario, bleeding the radiators is a must. Simply turn on the bleed valve located at the side of the radiator, anti-clockwise. To keep out contaminated water from dripping on the floor surface, place some towels beneath the radiators.

Ways to fix this problem

Here we have outlined some must-checks to handle the above issue.

• Thermostat of the heating system: For cases when the boiler works without the radiators being heated, there’s something fishy in the temperature regulator. Ensure the thermostat or timer is attuned properly.
• Air pockets in the internal heating system: If the radiators continue to malfunction, there may be trapped air in the system. When such a scenario happens, the radiators will alternatively seem cold as air pockets surround the heating system.

Manipulate the main valve and release air in such a case. However, do ensure that no water escapes from the system. Depending on the type of your installed system, you can also inspect the vents, air filters, and air ducts.

• Circulation pump: If the above reasons do not hold true for your case, the problem may be traced down to the circulation pump. Contact any of our licensed plumbing technicians for a hassle-free fix.
• Systemic disputes and accumulated dirt: Without routine maintenance, dirt and sludge may settle on to the heating system. This obstructs circulation, causing radiators to become overheated.

What if the problem is not associated with the thermostat or the boiler pressure?

If you obtain hot water without heating; while every component of the boiler being fine, here are some other things that you must note. 

• Broken diaphragms and airlocks: These are the prime indicators of motor valve failure, necessitating a professional plumber’s intervention.
• Blocked radiators: Central heating problems may indicate broken radiators and you may require bleeding them.

Radiators that feel cold over the sides and bottom but have warm upper surface, a thorough cleaning is essential.

• Uneven Radiator Heating: This is characterised by the radiator not bring able to circulate hot water from the boiler. In such a case, ventilation is necessary to prevent overheating of the radiator. Common cause for this issue is: not switching on the water pump shaft or problem with the pump itself.

To resolve this, you must first fill in the heating system with water. After that, bleed it using hot water from a cold water tank or cooling water pump shaft.  

This approach will turn the water shaft on, resulting in circulation of hot water from the radiator. If you require help in doing so, obtain professional guidance from our available plumbers.

• Heat Exchangers Problems: The heat exchanger is another troubling factor for many heating systems. Let’s understand the process in detail.

Fine rays of heat, typically around 60 ° C to 140 ° F can heat water by penetrating through a heat exchanger (connected to a cold water pipe). The hot water is then pumped into the radiator.

Even in the absence of central heating system, hot water continuously flows through the pipes. If the radiator is still cold, it is necessary to ensure both the boiler and the heating system is switched off.

If just one radiator is warm, the boiler is not faulty; however, if the heat is only lukewarm, consider shutting off the vent valve. If a radiator is overheating, attempt to bleed it and cover the vent valve with a towel to prevent dirty water from falling onto the floor.

• Radiator Sounds: If a conventional boiler is noisy, it suggests that the lower part of the heating system is heated, while the rest is not. For instance, if the heat exchanger on a single radiator fails while others function properly, that radiator can release steam, allowing the issue to be fixed by raising the temperature of all radiators significantly.

Due to the new boiler's condensation process, a small quantity of exhaust gas is released before it reaches the condensate pipes.

When the heat is activated in the home, a pump starts to pull water from the boiler and send it to the radiator. When the home hits the set temperature, the pump shuts off until the heating is disabled. Should your pump malfunction, you might hear whirring or grinding sounds, suggesting an issue that necessitates further examination by a heating engineer.

Conclusion: Hire our professional plumber to fix the issue!

We understand that having hot water without heating is a troublesome thing to handle. You may have the first thought of replacing the heater with a new one; but hold on!

The expense of repairing an old boiler is far reasonable than buying a brand new one. Hiring a competent emergency plumber can help you consistently evaluate your boiler’s state and functionality.

Book us for professional quotes on boiler repair in London now!