Vaillant Turbomax Plus 824e - Error 5F6 (or SF6) ? Info needed please.

[Mark Tee]

Hello.

I have a Turbomax Plus 824e boiler which has been limping along for some time. I am NOT GS registered but when it comes to things like replacing a screw in thermistor or topping up water pressure I am just about functional. I have no understanding or inclination to go inside the combustion chamber - just to make things clear - but I can find my way around a PCB without too much drama and replace things like screw-in thermistors etc.

However although I can usually find what is wrong from the fault codes and status codes, I have a code that I can find no reference to in the manuals.

SF6

the boiler has been working merrily (house warm to come home to) but radiators cooling down now and no hot water for shower.

Looked at the display - green light flashing and when reset / observed the following status messages shows:-

S20 Warm Start
S23 Ignition sequence (warm start)
S33 (which I cannot see in my manual)

and then lastly when I press the two buttons together

SF6

Amber and Red LED are off - Green light flashing - though was constant for a while once when I reset the boiler (off / on).

I have a vague feeling we had this once before a few years ago but I cannot remember what the fault was and if it was one of those things that was a DIY fix or if it was one of the few times I have needed an engineer to come and sort.

Despite S23 mentioning an ignition sequence, there is no typical "clicking" from the arc igntitor and also I cannot here any gas coming out which I THOUGHT could be heard if you listen carefully but I might be wrong on that.

If anyone can tell me what SF6 means that would be awesome please - as for some reason it doesn't seem to be in the manual. Also if it is something that is a fault OUTSIDE the combustion chamber (and nothing to do with gas), then some idea on what might need to be done would be welcome.

eg: Grotty connector to ignitor - check connector / water pump not operating (free off /replace) and so on.

Any help would be appreciated.

Thank you

Mark

 

[Dan Robinson]

Picture please.

 

[Mark Tee]

Hi Dan.

I can do that but do you want a picture of anything in particular?

I can take a photo of the LCD panel displaying the Status codes or the error code if you want - or do you want a photo of something else.

Happy to comply just not quite sure what you want me to photograph as just taking a pic of the tiny little screen displaying SF.6 or a status code wouldn't seem to help you much - but if it will help, I will cheerfully do it

 

[Dan Robinson]

Picture of the LCD with SF.6 please.

 

[petit_pablo]

SF.6 isnt a fault code that's in service mode. The 6 is actually a B for bath. Ie the diverter is in HW position.

What's the actual problem? Why are you pressing the two bottom buttons together?

Are you getting any actual F codes?

 

[Dan Robinson]

SF.6 isnt a fault code that's in service mode

Thought I was missing something obvious

 

[Mark Tee]

SF.6 isnt a fault code that's in service mode. The 6 is actually a B for bath. Ie the diverter is in HW position.

What's the actual problem? Why are you pressing the two bottom buttons together?

Are you getting any actual F codes?

Ahh thank you, I didn't realise.

I was pressing the two buttons together to see if there was a fault code - and mistook what I saw for one.

The actual problem is that there is no hot water and no central heating.

The only information I had was that which I posted:-

Status codes: S20, S23 (and once I am sure it said S33 but I may be mistaken as that seems not to be a valid code)
and then when I pressed the two buttons to see if there was a fault code, it showed: SF.6

Turned boiler off / on a few times, it makes a few chugging thumps (always has I am not sure what it is doing but it does it when working happily), then instead of firing up it just sits there and does nothing. Heating is on constant (as is hot water), but thermostat is ignored as is demand for hot water. It just sits there doing nothing.

Now I see it isn't actually a fault code, I am even more puzzled as to what the issue might be - it WAS working earlier as the house was warm - it was just starting to cool down. then realised shower was cold, hot taps cold - no heat when turning up thermostat. turned boiler off and on again, nothing.

So just trying to find ideas as to what would cause the issue.

 

[petit_pablo]

Saved fault codes are accessed by pressing bottom left and top right buttons together.

Did the boiler work when SF.b was displayed?
Can you hear the pump or fan running?

 

[Mark Tee]

No, the boiler hasn't fired since this happened. I can hear the pump (that is the one that always seems to do the "chug-chug-chug-chug" noise before running) and it sounds like a fan is running but NOT as loud as usual - when the boiler fires up, the fan makes an unmistakable sound - this is like a "quieter fan".

If it is just a fan fault that would be great - but I would have thought it would either:

1: not know it was not working so let the boiler fire
2: KNOW it was not working for safety reasons - in which case show an error code.

So yes, pump on and what sounds like a QUIET fan as opposed to the one you can hear outside from the flue - but not attempt to ignite gas.

Please excuse a delay in replying for a while now as I have been up about 20 hours and beginning to lag. Thank you for your help so far, I appreciate it.

Mark

 

[Agile]

If it is just a fan fault that would be great - but I would have thought it would either:

Mark

Perhaps you have not noticed that the fan is inside the combustion chamber which you said that you don't want to open!

But I suspect as you know where it is that you know exactly where it is and will be perfectly happy to tamper with it.

We are limited in the advice that we can offer. This should not include any advice on repairs which should not be done by a DIYer.

But post a picture of the display.


Last week we had a DIYer who was convinced his Vaillant was not showing an "S" code because he said that it was a figure "5".

 

[The831Bunny]

S.33 is a fan/flue/air pressure switch status code. Listen outside at the flue terminal to confirm that the fan is running (or not) while running a hot tap. Check D24 (press i button and + button to enter Diagnostic codes, press + to go up to D24, then press i to read status), code should read 1 while hot water is running. If not, (reads 0) you need a GS engineer to check your fan/flue/APS. Obviously not a DIY job!

 

[thereisawizza]

Best off to stop fiddling and get someone in, a little knowledge is dangerous.

 

[Mark Tee]

Perhaps you have not noticed that the fan is inside the combustion chamber which you said that you don't want to open!

But I suspect as you know where it is that you know exactly where it is and will be perfectly happy to tamper with it.

We are limited in the advice that we can offer. This should not include any advice on repairs which should not be done by a DIYer.

But post a picture of the display.


Last week we had a DIYer who was convinced his Vaillant was not showing an "S" code because he said that it was a figure "5".

My mistake. I thought the combustion chamber was the small central metal enclosure with the gas burner and heat exchanger inside - not the outer metal box covering the fan etc etc

It seemed reasonable to think that the combustion chamber was the bit in the middle with the gas burner - rather than the outer box with all manner of things "not in the line of combustion" - the fan being an example.

I will get a gas safe person to sort, I think we had an air pressure switch die once before

 

[Mark Tee]

Just in case anyone was interested, the fault was caused by a defective PCB - or far more specifically, a defective relay.

The relay activating the fan had suffered heavy arcing of the contacts and no longer made a reliable connection.

It dawned on me that it couldn't be an air pressure switch fault if the fan hadn't had a chance to "spool up" to MAKE a pressure difference to detect in the first place. Applied 240v directly to the fan connector from the PCB and fan spun straight up and allowed the boiler to fire.

Then tracked it back to the relay which, once replaced made it all happy again.

 

[Agile]

DIYers should not touch any combustion parts of a boler.

That includes the gas valve, burner, fan and flue.

As well as any part of the boiler which seals the combustion area from the room.

So in the case of this boiler, a DIYer should not remove the front cover of the boiler as that forms the room seal!

Tony