The Bosch boiler error code 70

The boiler starts automatically and when it is turned off, it stays on or off

The error code, 70, means that one of the heating zones is not running properly. It can’t be reset with a factory service button on the front of the appliance. Our tech support team would need to call you in order to fix this problem.

It can occur when water starts to leak and because it shuts the heating off, it’ll cut the gas supply automatically.

The Bosch boiler error code 70 stands for Timer Interlock Circuit Malfunction. This means the boiler may not turn off after the water reaches a certain temperature because the timer itself is malfunctioning.

Incorrect water regulation: low heating demand, lack of auxiliary heat or hot water production after a certain time, intermittent operation.

Operation of the boiler is interrupted due to an error in the fuel supply (such as air blocking) or low water level.

It might occur when starting up again if the steam purge solenoid valve (exhaust) is activated while entering the unit after it had been deactivated to interrupt the previous operation.

The error message merely indicates an overflowing water tank where the boilers use gravity to send water out of the system. Sometimes this overflow could happen due to external factors such as a broken or too high water pressure in the various pipes of your household.

The safest mode you should follow is immediately turn off the output and wait for it to refill and turn it back on. There are some factors that could explain this overflow that you should be aware of:

– If you have recently turned off the heating system, prior to checkout, some amount of hot water can be left inside the heating system.

– A leak or frozen pipe but also any other possible leak in your house such as exhaust from the water boiler;

– A malfunction on your Demand Controller (Thermostat);

– Any interruption in the electric power supply for more than 30 seconds;

– Any sharp fluctuations in the electric power supply.

Bosch boilers provide excellent quality and durability to customers.

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