Hello, I have one of these combi-boilers - two months old. Some time during last night the heating stopped working. Hot water still works. Pressure gauge shows zero.
Following the steps in the installation manual I closed the two heating valves, put the boiler into fill mode and refilled the heating circuit from the cold water feed (have a loop-back pipe) and got the pressure to 1.2 bar. Exit fill mode, opened the heating valves - pressure is holding steady.
However, still no heating - rads are all cold.
The outflow pipe to the rads is hot to the touch but I don't feel any vibration that I would expect from flowing water. Thermostat (Viessmann 100) is set to target of 27C and calling for rad heat (showing the rad symbol). Room temp is 16C. Wireless light on boiler occasionally flashes.
Both orange lights for rads and DHW are on.
I re-set the target rad water temp of 60C.
I re-paired the thermostat with the boiler.
The LCD display shows the tap symbol, a temperature (I presume the DHW temp) and an indicator at the bottom for I presume the gas. It does not show the rad symbol.
If I press the mode button it shows the rad symbol and "serv".
Any ideas what else to try? The manual isn't very useful and I couldn't find anything helpful about this particular boiler online. Thanks!!
Following the steps in the installation manual I closed the two heating valves, put the boiler into fill mode and refilled the heating circuit from the cold water feed (have a loop-back pipe) and got the pressure to 1.2 bar. Exit fill mode, opened the heating valves - pressure is holding steady.
However, still no heating - rads are all cold.
The outflow pipe to the rads is hot to the touch but I don't feel any vibration that I would expect from flowing water. Thermostat (Viessmann 100) is set to target of 27C and calling for rad heat (showing the rad symbol). Room temp is 16C. Wireless light on boiler occasionally flashes.
Both orange lights for rads and DHW are on.
I re-set the target rad water temp of 60C.
I re-paired the thermostat with the boiler.
The LCD display shows the tap symbol, a temperature (I presume the DHW temp) and an indicator at the bottom for I presume the gas. It does not show the rad symbol.
If I press the mode button it shows the rad symbol and "serv".
Any ideas what else to try? The manual isn't very useful and I couldn't find anything helpful about this particular boiler online. Thanks!!
Last edited: