The dreaded F.9... a question regarding flushing

[Rob Foster]

I got called to a Vaillant the other week where the sensor had blocked. He had the sensor replaced a few weeks before and it was blocked solid again. I am going to flush the system for them in a few weeks. The water way on the sensor is so small on these sensors that it doesn’t take much before they get blocked.

Its always been in my mind to insert a plate heat exchanger right next to the boiler and let it do a tight circuit and let the mucky stuff go around the heating system. The problem has been a heat exchanger which has decent sized pathways thro it and of course two pumps but there is one cause I found it - but its on a computer thats gone lala and is for service - is this a good idea ?

 

[Steve2381]

Changed out the pressure sensor - £23+vat. All working.
Thank you for everyone's advice

 

[Harvest Fields]

Changed out the pressure sensor - £23+vat. All working.
Thank you for everyone's advice

You’re welcome mate