Dear Gurus, I have had 2 heating engineers around and neither have solved my problem. Apologies for the large amount of info but it's a summary of what the problem is, what's been done and what is still happening.
We have an intermittent problem that occurs every 2-3 weeks. The Valliant boiler, when firing up first thing in the morning has an F75 code. It only happens in the winter months when the heating is on and doesn't happen for the 6 months when hot water only is being heated by the boiler. Only happens first thing in the morning - presumably the first firing of the day. After that, it will fire up all day and for the next few weeks without issue. The pressure, I think, is fine (closer to max and min). Resetting can be done 3 or 4 times when it's failed without working unless I add a bit more water into the system which seems to make it work every time. I only need to add a bit and then it works (ie pressure goes up from 70% to 75%). The pump seems to sound like it's starting to whirr for a second then stops.
Previous heating engineers have added a return and changed the pressure sensors, Neither seems to have made an difference. I bought a pump but both engineers said not to replace as the pump is working fine.
Final point is that roughly a small cup's worth of water drips out of the boiler valve over the course of about a month (see photo).
Any ideas as this has been going on for 2 years now.
Thanks in advance.
We have an intermittent problem that occurs every 2-3 weeks. The Valliant boiler, when firing up first thing in the morning has an F75 code. It only happens in the winter months when the heating is on and doesn't happen for the 6 months when hot water only is being heated by the boiler. Only happens first thing in the morning - presumably the first firing of the day. After that, it will fire up all day and for the next few weeks without issue. The pressure, I think, is fine (closer to max and min). Resetting can be done 3 or 4 times when it's failed without working unless I add a bit more water into the system which seems to make it work every time. I only need to add a bit and then it works (ie pressure goes up from 70% to 75%). The pump seems to sound like it's starting to whirr for a second then stops.
Previous heating engineers have added a return and changed the pressure sensors, Neither seems to have made an difference. I bought a pump but both engineers said not to replace as the pump is working fine.
Final point is that roughly a small cup's worth of water drips out of the boiler valve over the course of about a month (see photo).
Any ideas as this has been going on for 2 years now.
Thanks in advance.
