Installed about 20 months ago, to existing system. Within six months was showing fault F75.
Lots of chat between installing engineer and Vaillant service desk, various adjustments made to no avail. Eventually as customer, I called Vaillant, who send out an engineer who diagnosed "dirt on the sensor". Replaced sensor, system then worked fine.
After one year, serviced by Vaillant.
A few weeks ago started showing F75 fairly regularly, so I called Vaillant again. They sent out engineer who diagnosed dirt on the sensor and (I think) dirt in the pump. Replaced both. He expressed concern that the system might need a powerflush, as otherwise Vaillant might not be happy to continue to come out. (I must say that all three Vaillant engineers were helpful and fixed the problem at the time - the last remark about the powerfush, I am convinced, was to help.)
I had the powerflush done by, so far as I know, an entirely reputable firm, but awoke this morning to F75. Any views, ideas, suggestions?
Thank you
Lots of chat between installing engineer and Vaillant service desk, various adjustments made to no avail. Eventually as customer, I called Vaillant, who send out an engineer who diagnosed "dirt on the sensor". Replaced sensor, system then worked fine.
After one year, serviced by Vaillant.
A few weeks ago started showing F75 fairly regularly, so I called Vaillant again. They sent out engineer who diagnosed dirt on the sensor and (I think) dirt in the pump. Replaced both. He expressed concern that the system might need a powerflush, as otherwise Vaillant might not be happy to continue to come out. (I must say that all three Vaillant engineers were helpful and fixed the problem at the time - the last remark about the powerfush, I am convinced, was to help.)
I had the powerflush done by, so far as I know, an entirely reputable firm, but awoke this morning to F75. Any views, ideas, suggestions?
Thank you