Bosch Boiler error code 71

There is an error with the Bosch boiler system which is connected to a heating pump, this error destroys the pilot in the heating pump.

Bosch water boilers are known for creating some of the best kitchen appliances on the market. The company is renowned and places a heavy emphasis on designing and engineering its boilers with only the highest quality internal components. Bosch boilers are designed to be easy to install and will save both heating costs and prevents harmful environmental emissions.

There is an intermittent power conditioner fault on Bosch Boiler 701G-E XXTD PLUS

This fault can occur if the central heating has a cycle length of 2 or 5 minutes, or if power fluctuates too much at the supply voltage side below 228 volts.

The error code 71 appears on the control panel when there is an intermittent power conditioner fault with a diagnostic language code XXXXXX in XX group from 450 to 459

The boiler error code 71 means a malfunction in the electronic control module. The error code comes with a number of possible causes and solutions.

As an example, it can happen due to system overload, resistance in the electrical circuits, or no power supply. Some of the factors that can cause this problem are incorrect wiring, high-voltage circuits, low-voltage sensors, and defective thermostats.

It usually takes not more than a few days before the error clears on its own and the boiler starts working again on its own. The issue may start happening again otherwise, for example, when householder starts using too many hot showers over one day without enough restoring breaks in between to dissipate their heat efficiently through radiators.

When the hot water dial and the “program” light appear on the dashboard, it may indicate that this is a call fault code. The RHV module perceives surrounding noise caused by vibrations. When you attempt to manually stop the boiler from running, if it does not stop, and a pulsing glow emerges from behind the boiler’s left side – then this is a sign that motors and heating elements may be offline or there might be a shortage of gas and or electricity supply.

Before doing any troubleshooting you need to switch off the power supply and wait for at least 15 minutes for the cooling down process.

  1. The first thing that you need to do is identify the product. You can find it in the Bosch Error Code Log on their website. Once you find that the error code is 71, then go to page 4 in their user manual located here
  2. On that page, it tells you how to decode error codes and troubleshoot a unit with a 71 code. What it means by ’71’ is ‘Cycle On time, which means there is a problem with your circulator pump or the combustion blower, which causes water saturation and loss of circulation
  3. So if step (1) doesn’t help, then suggest trying these two steps: check for debris inside the vent tube and check for debris blocking any external air intakes near your product


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