Evening all,
I have a Vitodens 100-w (WB1a I think) the 4 pipe setup which is controlled by a Honeywell controller, one room thermostat and 1 cylinder thermostat.
The problem I have is that the boiler is not recognising the second demand placed on it.
i.e. If I start the DHW at 05:00 and the CH at 05:30 then the CH never comes on....even if the cylinder thermostat isn't demanding any supply. The same occurs in reverse. The only way to guarentee hot water and heating is to independantly set the times so they never overlap. It is so extreme that even if the DHW turns off at 06:00 the CH will still not turn on unless it is turned off and back on again.
The individual systems work fine with the thermostats - so DHW will kick in and out according to the thermostat demand so will the CH.
I think it is a control issue in the boiler as the LCD screen doesn't display both symbols at once...just the first one demanded..or nothing if the first one is turned off.
Anyone got any ideas? I have mailed Viessmann Tech support but I won't get an answer until next week probably and the plumber who fitted never picks up the phone on weekends.
I don't remember having this issue when it was installed (in 2008) and think it is a recent issue. Could there have been a loose connection in the wiring that I can check?
Thanks
Chris
I have a Vitodens 100-w (WB1a I think) the 4 pipe setup which is controlled by a Honeywell controller, one room thermostat and 1 cylinder thermostat.
The problem I have is that the boiler is not recognising the second demand placed on it.
i.e. If I start the DHW at 05:00 and the CH at 05:30 then the CH never comes on....even if the cylinder thermostat isn't demanding any supply. The same occurs in reverse. The only way to guarentee hot water and heating is to independantly set the times so they never overlap. It is so extreme that even if the DHW turns off at 06:00 the CH will still not turn on unless it is turned off and back on again.
The individual systems work fine with the thermostats - so DHW will kick in and out according to the thermostat demand so will the CH.
I think it is a control issue in the boiler as the LCD screen doesn't display both symbols at once...just the first one demanded..or nothing if the first one is turned off.
Anyone got any ideas? I have mailed Viessmann Tech support but I won't get an answer until next week probably and the plumber who fitted never picks up the phone on weekends.
I don't remember having this issue when it was installed (in 2008) and think it is a recent issue. Could there have been a loose connection in the wiring that I can check?
Thanks
Chris