If it’s not staying lit though, then you’re probably dealing with a thermocouple issue. The thermocouple of a boiler system is a long metal wire that acts as a heat sensor for the pilot light. One end of this wire is installed near the flame to be heated by it, and the other end is connected to the gas valve.

Why does my boiler fire up then cut out?

Your combi boiler firing up then cutting out is nothing to worry about. It is usually the result of its ‘preheat’ function. Basically, it’s a way of ensuring that hot water is ready to be used in the taps throughout your home.

When I release the pilot button the flame goes out?

Yes, either the thermocouple is going bad, it’s not getting heated, or something is wrong with the controller. The most likely of those is that the thermocouple needs to be replaced. The button you press to light the pilot bypasses the thermocouple.

Why does my boiler keep running?

A thermostat fault may be causing your boiler to continue to fire up and stay on. You could attempt to test this issue yourself by turning your thermostat temperature levels down to see if this brings about any change, you could also try to replace the device’s batteries.

Why does my combi boiler keep locking out?

What Does Lockout Mean on a Boiler? A boiler lockout is a shut-down procedure that initiates when a boiler is not working within certain tolerances. Boilers can lock out due to low/high water pressure, lack of, or no fuel supply (gas, LPG or oil), a blockage in the system, or the lack of power to electronic components.

What would cause a pilot light to not stay lit?

The Buildup of Dirt or Debris Around The Pilot Light – Over the years it’s easy for dust, debris, and dirt to build up on the inside of the intake valve where the pilot light resides. This makes it difficult for the flame to breath and as a result causes the pilot light to go out suddenly.

Why will my gas heater not stay lit?

If your pilot light won’t stay alight, it might be the thermocouple. Sometimes dust buildup collects on the thermocouple and blocks the sensor. Try cleaning the thermocouple and then relighting the pilot light. If it continues to go out, the thermocouple might need to be replaced.

Why does my water heater not stay lit?

Thermocouple Issues

If it senses that your water heater pilot light keeps going out, the thermocouple will shift off the gas supply to the heater. Over time, thermocouples can malfunction, accumulate dust buildup, or the device can get bent away from the pilot light’s flame.

How much does it cost to replace a thermocouple on a boiler?

It costs $150 to $250 to replace a thermocouple. It checks to make sure the pilot light is on. It will shut the gas off if it’s not.

How much does a thermocouple cost?

1 cause of pilot lights that won’t stay lit is a worn-out thermocouple. It’s easy to replace and a new one costs $5 to $10. Rather than trying to unfasten the thermocouple inside the water heater’s burning chamber, it’s easier to remove the whole burner and thermocouple assembly.

How much does it cost to replace a thermocouple UK?

Although a replacement thermocouple is an inexpensive part, the cost for a boiler engineer to fit it is likely to bring your boiler’s thermocouple replacement to approximately £150.

Why does my boiler keeps turning off?

If there is an issue with your temperature control valve or TCV as they’re known, it means that the water temperature in your boiler is no longer regulated. If the temperature gets too high it can cause leaks within your system. This will cause your boiler to shut off to protect itself from overheating.

Why does my combi boiler keep running?

If the boiler keeps running when the programmer is off, then the system needs to be inspected further. A typical control system consists of various components, including a thermostat, programmer, timer, motorized valve, pump, and heating element. One or more of these components could be the culprit.

Why is my heating coming on when it’s turned off?

A check valve is used to stop the natural convection from warming up your home when your heating is switched off. If the check valve is broken or blocked, heat will rise through your system causing your radiators to stay hot. Once again, contact a qualified professional to come and check what the problem is.

How do I stop my boiler from locking out?

Generally though, most boilers will lockout if the pressure is below 0.6 bar or above 3 bar. If your boiler pressure is low, you can increase it by adding water to the system via the filling loop. If the pressure is high, you can reduce it by bleeding the radiator valves.

Is it safe to reset boiler?

If your heating isn’t coming on and you’ve checked the power supply and pressure you may need to reset the boiler. It’s a very simple and safe thing for you to do in your own home.

What is a lockout on a boiler?

A boiler lockout means that your boiler has shut down. When a boiler lockout occurs, it stops working and the display will flash up with an error code to inform you of the fault.