Sometimes, we go to give the hot water but it only comes out cold, we approach the boiler and it has not started. This may be due to the security system preventing it from starting because it has detected a fault in the boiler. Here are the most common:
Obstruction of the smoke outlet: when there is a snowfall or a storm, many calls are made to us because the boiler does not start. In this case, we ask users to look at the error code that appears on the boiler’s screen or display, since it is usually an obstruction.
The smoke outlet pipe, which is usually located on the façade, becomes clogged by snow and the boiler detects it thanks to a sensor. The solution is simple; use any element at hand to try to remove the snow from the smoke outlet.
Condensing boilers and sealed Boiler Repair collect the air necessary for combustion through a coaxial tube (a tube inside another tube). Through one they expel the smoke and through the other they collect the air from the outside. If the tubes are clogged, neither combustion nor smoke can be expelled, so the boiler’s safety system prevents it from starting up.
- Lack of pressure: if the sensor detects that there is a lack of pressure, the boiler does not start.
- Temperature probe failure: When the heating works but there is no hot water, it may be because the DHW temperature probe fails.
- Failure in the flow detector: it is the sensor that is responsible for detecting when we open a tap. This can be by magnet, membrane or turbine. One way to check this is to open many faucets at the same time to see if the detector is activated.
- Gas problem: it can happen that the spark plug generates a spark but no gas reaches the boiler. In this case, check that all the gas taps are open.
- It is not connected: if the boiler does not receive electricity it is impossible for it to start. It may be that it is not plugged in, that part of the electrical installation has stopped working or the fuse has blown.
The boiler turns on but does not heat the water
When we activate a faucet and the boiler detects this request for hot water, it starts working to send us that hot water. But sometimes, even if the hot water is turned on, it does not reach its destination. This can happen because of:
Boiler 3-way valve
Failure in the 3-way valve: in its normal position, it causes the water to reach the heating. When there is a demand for water, the valve changes its position so that the water reaches the DHW circuit. If the valve stays stuck you can run out of hot water or heating depending on the position in which it has been stuck.
If the valve is stuck in the heat position, you may still have heat but no hot water.
Circulation failure: when the pump does not work, the boiler starts and heats the water, but as it does not circulate, the temperature and pressure increase, causing the boiler to block for safety reasons.