Boiler Error Code - Advice - Vaillant EcoTec 831

DIYhelp76

Hi,

We have a Vaillant EcoTEc 831 gas boiler - approx. 18 years old.  Keeps throwing up error codes and stopping working.  We have used the reset button and it always restarts. This has been happening for several years from time to time.

This year, and the last few weeks especially, it stops every week, sometimes every other day.  Turning if off at mains overnight and using reset button usually gets it going again, but sometimes lately it can take 5-6 reset attempts.

It is properly pressured and was serviced last year.

Is there a Vaillant expert who could help diagnose fault and say if it's worth repairing or replacing - and likely costs for both option?  Would like to avoid unnecessary cost and upheaval of a replacement, if a repair could be viable.  Saw some comments online to say it might only be a "capacitator" on the PCB that needs replacing at minimal cost, but not sure how to diagnose.

Many thx for any advice on this.

ic

What are the error codes?

FreeBear

DIYhelp76 said:  Would like to avoid unnecessary cost and upheaval of a replacement, if a repair could be viable.  Saw some comments online to say it might only be a "capacitator" on the PCB that needs replacing at minimal cost, but not sure how to diagnose.

Finding a faulty capacitor and replacing it is beyond the skillset of most heating engineers. You could probably find a refurbished board at a reasonable price (you usually have to send the old board back to get the best price). But you may find many Gas Safe engineers won't fit a part that you have supplied.

Not all faults are within the main PCB. Faulty sensors can also throw up cryptic error codes. Depending on the errors being displayed, it may pay to get Vaillant to do a fixed price repair.

DIYhelp76

Hi, thanks for the replies.  The fault codes have varied over time, but most recently it is F61 (sometimes with an F27 appearing after doing an F61 reset).  Does this help narrow down the likely issue at all?

Recent pattern:

• Turn on hot tap, boiler works for a day or two before presenting F61 error code.
• Try to do re-set immediately - 5 or 6 reset attempts, may or may not come back.
• Switch boiler off at mains for a day or overnight. Do a reset, clears F61 at first attempt and boiler works again for hot water for a day or two or a week or two before F61 re-appears.
• Obviously not using central heating right now, so not sure what will happen when that is switched on.

WIAWSNB

DIYhelp76 said:

Hi, thanks for the replies.  The fault codes have varied over time, but most recently it is F61 (sometimes with an F27 appearing after doing an F61 reset).  Does this help narrow down the likely issue at all?

Recent pattern:

• Turn on hot tap, boiler works for a day or two before presenting F61 error code.
• Try to do re-set immediately - 5 or 6 reset attempts, may or may not come back.
• Switch boiler off at mains for a day or overnight. Do a reset, clears F61 at first attempt and boiler works again for hot water for a day or two or a week or two before F61 re-appears.
• Obviously not using central heating right now, so not sure what will happen when that is switched on.

What do these two codes mean?

Le_Kirk

These are the fault codes: -

F61 The ASIC or µControl does not run in the defined times.

Possible cause:

• Fault in the electrical connection for the gas valve assembly
• PCB defective

How to fix it:

• This is a case for an expert. Don’t try to solve it yourself as it can be dangerous.

F27 A flame signal has been detected while the burner is off.

Possible cause:

• Gas solenoid valve not leaktight
• PCB defective

How to fix it:

• This is a case for an expert. Don’t try to solve it yourself as it can be dangerous.

FreeBear

Le_Kirk said:

How to fix it:

• This is a case for an expert. Don’t try to solve it yourself as it can be dangerous.

Anything that requires the front panel to be removed is a job for a Gas Safe engineer. Anyone that suggests that these types of repairs can be DIY'd needs taking outside and given a good slap and then banned.

Gas is dangerous (as are the products of combustion). Any small error that results in a leak could have fatal consequences.

WIAWSNB

FreeBear said:

Le_Kirk said:

How to fix it:

• This is a case for an expert. Don’t try to solve it yourself as it can be dangerous.

Anything that requires the front panel to be removed is a job for a Gas Safe engineer. Anyone that suggests that these types of repairs can be DIY'd needs taking outside and given a good slap and then banned.

Gas is dangerous (as are the products of combustion). Any small error that results in a leak could have fatal consequences.

Yes and no.
And I ain't going to suggest anyone does this.
But on my Glowworm, the front cover is purely decorative, and fully open to the boiler underside.
The PCB is inside the drop-down front control panel, and a doddle to replace. I did this a few months back with a recon item from t'Bay - £35, I think I recall. I also bought new relays in order to fix the original.
No - cough - gas issues.
But I ain't going to suggest anyone does this.