I have a 6 year old Vaillant Ecotec Exclusive 838 that regularly shuts off. This has happened since new and seems to happen the most when the heating is on (but not necessarily actually running ie just sitting at the programmed temperature) and then you turn the hot water on. There is a very loud whooshing noise like a kettle boiling dry and then the boiler shuts off. There was previously an F20 error code and the display says water deficiency (but there is plenty of water in the system). Vaillant have been out several times over the years and in Nov 2010 just about replaced everything - PCB board (for the second time), temperature monitor, pump, NTC sensor, system pressure sensor - all done under a service scheme warranty. The same problem has now started again only this time there is no error code being recorded. I'm in a bit of a spot in that if I get the Valiant engineer out again I know he will do nothing as there is no error code - he has said this before. The system currently resets after being switched on and off and works ok for a while but obviously this is a nuisance to have to keep doing this and clearly there is something wrong for it to do this in the first place. The Vaillant engineer seemed to have no experience of this fault and from my observations just changed parts in the hope that something worked. I think the thing that has worked the longest was changing the PCB as this was done last after the other things failed to cure the problem. Is this a regular problem on these boilers?
I'd really appreciate some experienced advice and if anyone has come across this before and has a solution. Also can I ask, is it ok when the heating is on for the pressure to be 2.5 at 70 degrees - this is very close to the red line on the pressure indicator and I wonder if I turned it up higher if it might actually go into the red line
My service scheme via Homeserve / Vaillant is up for renewal in Jan and I am thinking of looking elsewhere to a competent independent Vaillant expert perhaps - if I can find one. I am in the Tyne and Wear area. I was thinking that it might also be useful to have a more thorough service carried out such as cleaning the combustion chamber etc at the same time. The regular service seems to just be a gas check and clean the condensate trap and presumably after 6 years other things will need be done.
Any advice would be very much appreciated. The boiler generally has been ok apart from this reoccurring fault.
Many thanks
Paul
I'd really appreciate some experienced advice and if anyone has come across this before and has a solution. Also can I ask, is it ok when the heating is on for the pressure to be 2.5 at 70 degrees - this is very close to the red line on the pressure indicator and I wonder if I turned it up higher if it might actually go into the red line
My service scheme via Homeserve / Vaillant is up for renewal in Jan and I am thinking of looking elsewhere to a competent independent Vaillant expert perhaps - if I can find one. I am in the Tyne and Wear area. I was thinking that it might also be useful to have a more thorough service carried out such as cleaning the combustion chamber etc at the same time. The regular service seems to just be a gas check and clean the condensate trap and presumably after 6 years other things will need be done.
Any advice would be very much appreciated. The boiler generally has been ok apart from this reoccurring fault.
Many thanks
Paul
