Mend > Home Heating Systems

Ariston Fault Code - MicroGenus Combi Boiler?

Hi,

My combi keeps cutting out and displaying the code A77. Usually only happens when running HW but could be a co-incidence.

Also - boiler makes a whining noise at times for long periods but only when CH is running - not HW.

Just over a year old but I think they give a 2 year warranty...here's hoping!

Any clues would be helpful!

Thanks.

Richard
November 2007

Ariston Heating, Home Heating Systems Fault Boiler Running

Need to renew sensor located in the recupirator. The fan has to be removed to do this. Could also be a blocked condensate drain.Both faults will bring up A 77.

m b kenny plumbing
April 2014

My plumber has changed a number of items to no avail, however after taking everything apart he found that the boiler had been installed with a restrictor in the flue. According to Ariston this is a big no no on this type of installation as it causes excessive condensation to be produced which it is not designed to cope with. Another problem can be that the boiler is not straight, this causes water to build up against the sensors and not run away. Restrictor has been removed and to date no more problems. Fingers crossed.

Lee
January 2008