Viessmann boiler error U3

Viessmann boiler error U3 is a common issue due to a faulty boiler.

Many reasons can cause this error; the most common is a faulty gas valve or pressure sensor.

Some of the other causes include:

– Gas or oil pressure too high

– The pump is not working as it should be

– The pressure sensor failed to close, and the pressure became too high

– The pump failed to start

Fault code U3 is a boiler fault that signifies the need for a thermal limiter replacement. This can be caused by a power surge, overheating of the boiler or excessive use.

It’s important to note that this error is not related to any other system faults. Further, if this error code persists and is not addressed, it could lead to bigger problems in the future.

With the help of an expert plumber, you can avoid this problem in future. But if they are unavailable in your vicinity, go through the below-mentioned steps to get over this issue.

– Check your water pressure

– Get a water leak detector and start looking for leaks in your home

– Inspect the plumbing connections at the point where it connects to the boiler

– Check whether the gas valve is open or closed

“Inspections, Installations, Repairs & Maintenance”