Vaillant turbomax pro 828E - no heating

[FarmerGiles]

Hi All,

I have recently had a Vaillant 828e installed, hot water working fine.

honeywell 6360 mech stat will not turn on heating if I check the the status codes it states the external controls are calling for heating when I turn 6360 on.

I can turn on heating in sfh mode and its works perfectly. I have removed the internal timeswitch to rule this out and no change.

Please help - Thanks

 

[chrishutt]

sfh mode

What's sfh mode?

 

[FarmerGiles]

Not sure really!! saw it on another post regarding same boiler different problem but basically involves holding the bottom two buttons of the four on panel.

This turns heating on and displays sfh in the display panel. Heating stays on until same buttons pressed.

 

[chrishutt]

If this is the Turbomax plus 828e, holding the bottom two buttons (+ and -) simultaneously brings up "Diagnostic Modes" to the display. These codes have the form "d.00, d.01, d.02 etc. Nothing about "sfh" that I can see in the manual!

 

[blahblah]

Sfh (sf allegedly short for chimney sweep in German) will fire the boiler to the max ch rate (but not higher than any part load dialled in). If you turn on a tap it will go to the max for hw. Therefore if its firing correctly then the problem should be outside of the boiler.

 

[FarmerGiles]

I have also gone through the manual and as well as not finding anything on the sfh, I can't find any info on firing up the boiler this way either. If I work through the troubleshooting it leaves me at check / replace fan or replace electronic board. As it seems to work fine manually this has left me baffled (not difficult)

Using the diagnostic mode d.08 the boiler states that when the thermostat is turned up the diagnostic code is changing to detect the call for heating, is it possible that the thermostat even though it is calling for heat is faulty in some way (as blahblah states an external problem)

 

[chrishutt]

Giles, your topic title says Vaillant turbomax pro 828e. I didn't think the pro had the status and diagnostic codes, and that it was designated 28e rather than 828e. Do you actually have the turbomax plus?

You suggest an external stat fault, but as far as the boiler is concerned, there is either a call for heat or not. Your problem is more complex.

 

[Paul Barker]

Not necessarily Chris in Chimney Sweep mode a boiler comes on regardless of a call for heat. It could still simply be that no call for heat is arriving at the boiler. That's the first thing I'd check, or just use chimney sweep mode all winter.

 

[chrishutt]

Thanks Paul, I'm getting the picture with this chimney sweep mode, it's like the flue testing switch on some boilers, to enable flue gas analysis without thermostat switching and gas modulation that would otherwise arise.

In case anyone's interested, the role of the schornsteinfeger (chimney sweep) in Germany is highly regulated and apparently he has a monopoly on testing flues, hence the "sfh"reference. My earlier post was wrong in saying that "+ and -" pressed together gets diagnostic modes - that's "i and +" together!

But getting back to the problem, the poster says that status code shows heating being called for - what status code is being shown, exactly?

 

[ChrisR]

schornsteinfeger

Aw, I wanted to be the smartarse to come up with that Never mind, on holiday anyway, Byeee

 

[FarmerGiles]

Chris, my appologies for being such a plum my boiler is infact as you state the turbomax plus (not pro as I previously stated). reading to many posts for answers I think going slightly mad.

The boiler in diagnostic mode d.08 (External controls heat demand) changes from 0 (0=open no demand) to 1 when stat turned on (1=closed demand). Can you tell Im working through the manual.

 

[chrishutt]

The boiler in diagnostic mode d.08

But what is the status code(e.g. S.00) - which comes up when you press "i"?

 

[FarmerGiles]

It comes up S.31 summer mode (heating control knob in off position) this doesn't change whether thermostat is on or off.

 

[chrishutt]

And is the heating control knob in the off position by any chance?

 

[FarmerGiles]

Hi Chris, it was off I realised that I turned it off when I took the internal timeswitch. So now the ch is coming on (big thanks for your help and others help) I tried to put the timeswitch back in and this stops the thermostat calling for heat but Im not to fussed about that at the moment, leaving it out for the time being.

I do now have another issue which is that after the heating has been on for a few minutes status is going to S.07 pump overrun and ch is going off. Any ideas?

Thanks again for your help it's really appreciated.