Boiler stopped: now says, 'Check air/flue system'

[maryos]

Combi boiler: Vaillant Turbomax 842E

This morning I woke to no hot water and no heating. The pressure guage on the boiler was too low and I refilled this up to 1 bar (I've done this once before about six months ago). For about 5 minutes I was then able to get hot water after which it gave up once again.

After getting back home this evening I have checked and bled all my radiators - in the process discovering that one of them was indeed mostly full of air. Whereas four of the five radiators now spurt out water, one of them I can't get to do more than trickle - seems odd (but as is probably very obvious, I am not very experienced at this!) I then reset the presssure guage - again up to 1 bar (I think in the process of bleeding the radiators it had dropped - does that make sense?)

Unfortunately the boiler still isn't working! I am fairly resigned to calling somebody out, but is there anything else I could try??? The status key tells me to 'Check air / flue system.'

Any comments gratefully received

 

[bengasman]

valves on the one rad may be stuck closed/almost closed. would not stop boiler from coming on. lots of air in rads indicates leak somewhere

 

[giblets]

Does the fan on the boiler start up but no ignition?

This fault code normally indicates a failed air pressure switch.

 

[cozzmic]

Try turning the power off for a wee while it might reset it. Or is there an overheat reset button some where on the case. Not familular with the boiler.

 

[maryos]

The fan certainly does start up and I can hear it trying to ignite. I can't tell if it actually does ignite (embarrassingly) - I can't see gas pilot light. After a few moments (longer than it usually takes during normal heating) the fan noise stops.

There is a reset button (symbol is of a flame crossed out), which I have now found and tried - but it has had no effect. I have turned boiler off at power as suggested and will try again in a while.

Thank you for all your comments - and at this time of night. Really appreciated! Thanks so much

 

[maryos]

Just realised..! the 'yellow flame indicator' must be equivalent to pilot light and this does NOT come on any more. Only the green indicator light comes on - in fact it flashes continuously. The red 'lock out indicator' is not on either.

Also the boiler is not actually displaying a fault on the screen. It only shows me the code S.33 for 'Check air / flue system' when I press the status button. All over my manual it tells me that when there is a problem the red light will flash (it is not) and a fault code (F. something) will display.

 

[onion_soup]

...... It only shows me the code S.33 for 'Check air / flue system' when I press the status button. All over my manual it tells me that when there is a problem the red light will flash (it is not) and a fault code (F. something) will display.

read here for aps fault on 824

//www.diynot.com/forums/viewtopic.php?p=180125#180125

 

[maryos]

Thank you very much -- again -- for those helpful replies. But I am now extremely puzzled! I turned the power for the boiler back on and tested first water, then heating separately. The fan (noise) came on but no ignition light for either and eventually fan went back off again, so still nothing. I left water off and switched heating to timer, which was equivalent to leaving it on. After a few minutes the boiler powered up again, still nothing happened. Then some more (5? 10?) minutes later it did the same again and this time the yellow ignition light did come on and stayed on. After a few more minutes of this I turned water back on and tested it and it did indeed come warm.

I am very grateful. I don't think I would have persisted without the various suggestions. But I am also perplexed and wondering if I need to be braced for it to fail again in the near future.

Any comments would be welcome

 

[Agile]

All of you apparently recognise a Turbomax 842/

Its obviously one that I have never encountered.

Could someone describe its salient features.

Tony

 

[bengasman]

All of you apparently recognise a Turbomax 842/

Its obviously one that I have never encountered.

Could someone describe its salient features.

Tony

824 more familiar, probably a typo

 

[maryos]

you are right - it is 824 - sorry!