I have a 13 year old Vaillant ecoMAX828 which has developed a problem with the hot water which I hope someone recognizes and can advise what to do.
The problem happens a couple of times a day when the HW is run, and most often when the CH is on as well. The boiler gets locked into a (1 second) cycle of trying to switch on to heat the HW and cutting out again, probably because it is too hot as the temperature readout shows high 60's or 70's, which is higher than the HW setting. When it is in this loop I cannot get a response from the i button to see any fault code.
When the HW does work it gets very hot then after 30 seconds it cools down significantly and makes it impossible to run a hot bath.
I live in a hard water area and it appears as if something is furred up which causes a delay (hysteresis) between the actual water temp and what the sensor detects, so the water gets too hot hence triggers the cut out.
Is this sensible? Has anyone else experienced this problem and knows how to fix it? Thanks for reading.
The problem happens a couple of times a day when the HW is run, and most often when the CH is on as well. The boiler gets locked into a (1 second) cycle of trying to switch on to heat the HW and cutting out again, probably because it is too hot as the temperature readout shows high 60's or 70's, which is higher than the HW setting. When it is in this loop I cannot get a response from the i button to see any fault code.
When the HW does work it gets very hot then after 30 seconds it cools down significantly and makes it impossible to run a hot bath.
I live in a hard water area and it appears as if something is furred up which causes a delay (hysteresis) between the actual water temp and what the sensor detects, so the water gets too hot hence triggers the cut out.
Is this sensible? Has anyone else experienced this problem and knows how to fix it? Thanks for reading.
