Simply replacing the radiator cap solved the problem. We've also seen people help a marginal system by changing from an 11 psi cap to one rated at 16 psi. Why not just jump to the highest psi caps available? Because cooling systems are designed for specific pressure.
Bad Water Pump or Thermostat
If the thermostat goes down, the system will not know when to release fluid into the radiator, and if the water pump fails, the system will not have the pressure necessary to circulate the coolant. If either of these things happens, the radiator will not work as designed.
Ideally, the radiator needs to be squared up to the air. Scoops, lips, deflectors and recessed panels can be used to improve air flow when the frontal area of a vehicle is less than ideal. The next issue relating to air flow that requires serious attention is the fan.
Use a Radiator key:
Use the radiator key, attach it to the bleed valve, and rotate anticlockwise not more than half a turn. After doing this, you will hear a hissing sound, indicating that the trapped air is escaping. This will guarantee that all the trapped air has been released.
Locate the filling loop, often found on the underside of your boiler. Open both valves to allow water into your heating system. Keep an eye on the pressure gauge and close the valves when the pressure reaches 1.5 bar. Switch on your boiler and reset the fault code (if necessary).
Remove the radiator fill cap and pour the heavy-duty radiator flush into the radiator. Fill the remaining empty part of the radiator with fresh water. Place the cap back on the radiator. Start your vehicle and keep it running for almost 15 minutes, allowing the radiator flush to move through the entire cooling system.
Too little pressure will cause the coolant to boil off, leaving nothing inside the system to cool your vehicle. In general, certain signs will help you to know that you've got a problem with your radiator cap. From a collapsed hose to an overflowing reservoir, we'll show you what to look out for.
Bleeding radiators
One of the most common causes of pressure loss is if you've recently bled your radiators. As air is released from your central heating system, it lowers the pressure. So make sure you check the pressure gauge after bleeding a radiator.
This issue could be caused by a faulty thermostat, an obstruction in the radiator, a fan or the water pump has malfunctioned preventing the coolant from flowing and dissipating heat as intended.
The cap's pressure rating has nothing to do with regulating your engine's coolant temperature, nor will it make your engine run cooler. Depending upon the original application you will see original radiator caps rated for anywhere from 13 psi up to 18 psi.
Conclusion. Radiator fan boosters can be a cost-effective and energy-efficient solution for improving heating efficiency in homes. They work by circulating warm air more effectively around a room, reducing the amount of energy needed to maintain a comfortable temperature.
It is designed to hold a certain amount of pressure inside the system, and to release the pressure when it exceeds a pre-determined level. Why do you want pressure in the cooling system? Actually, you don't get a choice. As the coolant heats up, it expands.
Bleed your radiators to ensure radiator efficiency
Trapped air in your heating system is not only easy to spot, but also simple to remedy and a guaranteed way to improve radiator efficiency.
If the cap cannot maintain the correct pressure, the coolant might boil off, reducing its ability to absorb heat, and this increases the temperature of the engine, leading to overheating and engine failure. This can be particularly noticeable during long drives or in stop-and-go traffic.
Thermostat: The thermostat regulates the flow of coolant into the engine keeping it at its optimum operating temperature. The thermostat is closed when the engine is cold. As the engine heats up, the thermostat opens and allows coolant from the radiator to circulate.
Check your radiator for a thermostatic valve. This device lets you adjust the setting on the radiator so that you can control how much heat it puts out. Your radiator might not have a thermostatic valve if it's older, but you can always have one installed if you wish to have more control of your radiator's heat output.
Your lockshield valve is usually covered with a plastic cap – 'lockshield' means the plastic cap shields it from being accidentally adjusted or knocked. If you remove the cap you'll see the top of the spindle, which you can turn with a spanner to adjust the flow of water through the radiator.