Vaillant boiler issues F28 on ecotec 430 not the normal culprit

[gmartine]

We sympathise with your frustration but do give him a chance to get back to you and make the necessary changes as occasionally a combination of events especially where electronics and sensors are concerned can lead to anomolies that aren't easily explained by a fault code. With an untracable intermittent fault it may eventually be a case of replacing parts in a systematic semi-educated way which is expensive but still no guarantee. Do continue to keep us updated as we're also on a learning curve albeit at your inconvenience, and goodluck hopefully you won't need it now Andrew is on the case.

 

[Navi Bhander]

We sympathise with your frustration but do give him a chance to get back to you and make the necessary changes as occasionally a combination of events especially where electronics and sensors are concerned can lead to anomolies that aren't easily explained by a fault code. With an untracable intermittent fault it may eventually be a case of replacing parts in a systematic semi-educated way which is expensive but still no guarantee. Do continue to keep us updated as we're also on a learning curve albeit at your inconvenience, and goodluck hopefully you won't need it now Andrew is on the case.

I fully understand intermittent issues and I respect Andrew’s honesty with all the advice. He’s not given up either, so he’s going to contact his Vailliant chap to do some further fault finding and send someone else over too.

The system installation design will be getting fixed regardless, he’s just doing some research into the evohome system to make sure it will all integrate and function better.

 

[gmartine]

I'm reluctant to tread on anybody toes mid-investigation, let it run it's course but this would be my next areas of concern...

Igniter, gas valve and electronics. You never know both boilers could've been installed with faulty igniters, highly unlikely but a cheapish swap out.

 

[Navi Bhander]

I'm reluctant to tread on anybody toes mid-investigation, let it run it's course but this this would be my next areas of concern...

– There’s a problem with the gas supply to the boiler.

– [/s]There’s air in the pipes.

– The pressure of the gas flow is too low.

– Igniter is defective.

– There is a fault in the gas valve.

– Electronics are defective.

The good thing with Andrew was he’s sonopen to ideas he even asked if the forum had suggested anything else!

How would air enter the gas system?

Once the boiler has ignited it’s fine, it doesn’t switch on which brings up the F28.

 

[gmartine]

See above post again Navi, my strike throughs are like your boilers... unpredictable. It sounds like everything has been done with regards to your gas supply, F28 error includes gas + ignition so that side of things require further investigation imo hence recommending the igniter swap out. It may at this point ask be worth asking Vaillant to participate again IF parts are required.

 

[Gasmk1]

See above post again Navi, my strike throughs are like your boilers... unpredictable. It sounds like everything has been done with regards to your gas supply, F28 error includes gas + ignition so that side of things require further investigation imo hence recommending the igniter swap out. It may at this point ask Vaillant to participate again IF parts are required.

can this fault also so be due to ignition lead

 

[gmartine]

Probably about as unlikely as a faulty igniter, no point assuming anything at this stage.

The simultaneous fault occuring in both boilers is the kicker here which is why everybody has concentrated on the gas side of things to date. Could've been a late Friday afternoon at the Vaillant factory when these boilers rolled out, who knows.

 

[Navi Bhander]

See above post again Navi, my strike throughs are like your boilers... unpredictable. It sounds like everything has been done with regards to your gas supply, F28 error includes gas + ignition so that side of things require further investigation imo hence recommending the igniter swap out. It may at this point ask be worth asking Vaillant to participate again IF parts are required.

Yes, Andrew has the same thoughts. He’s asked to get Vailliant back over again to check them.

The only baffling thing was one boiler will never switch off by itself, always both of them together at the exact same time.

But when you’re clutching at straws and have tried everything then sometimes the most unlikely cause can be the cause.

I’m stuck at work today so will call them in the morning and get an engineer out.

 

[gmartine]

The only baffling thing was one boiler will never switch off by itself, always both of them together at the exact same time.

I don't think your boilers have been paired properly so that may cause some issues. It sounds like whoever designed your semi-commercial system has had a go with trying to design/install it by scaling up their domestic knowledge. I'm sure Andrew will get to the bottom of it...eventually.

 

[Jerry]

I look forward to finding out what the fault is.

 

[Aire]

Did Andrew check the termination of the condensates? Both go to the same pipe so if there is a blockage or partial blockage it may cause an intermittent f28 fault code.

 

[Navi Bhander]

Did Andrew check the termination of the condensates? Both go to the same pipe so if there is a blockage or partial blockage it may cause an intermittent f28 fault code.

This was checked by another gas safe engineer before as well. I remember him pouring water down there and stating there definitely was no issue on that side.

Well the one boiler still hasn’t kicked out yet, but when it ignites it will switch off within 2 secs and then fire back up after 5 seconds.

So the confusing bit is the boiler will actually ignite then extinguish instead immediately, then reignite and work. It does this most times.

Which would mean the flow rate wouldn’t matter, has pressure is fine, the electrics should be fine as it ignites. Andrew even thought it could be a dodgy flue but there are 2 different flues and yet both have the same fault at the same time!

Will be on the phone with Vaillant in the morning and see.

Andrew will pop back as he wants to check the HT lead or something or another as well.

The system layout that he suggests is using the boilers independently, one to do the underfloor and one for the radiators and hot water tank. He wants me to get the accuweather or something on the boilers fitted but it makes the evohome system half redundant so will need to have a think.

 

[chris watkins]

Did Andrew check the termination of the condensates? Both go to the same pipe so if there is a blockage or partial blockage it may cause an intermittent f28 fault code.

Spoke to him today, I think he was going back to check a few things including disconnecting the wastes's.
It makes sense, it could be double trapped or part obstructed.
It has been happening from the start. Would effect both boilers or just the one. Mainly happens around start up just when more condense is produced.
worth a check.
Has anybody pulled the burners to check HeatX and electrodes I wonder ?

 

[Navi Bhander]

Spoke to him today, I think he was going back to check a few things including disconnecting the wastes's.
It makes sense, it could be double trapped or part obstructed.
It has been happening from the start. Would effect both boilers or just the one. Mainly happens around start up just when more condense is produced.
worth a check.
Has anybody pulled the burners to check HeatX and electrodes I wonder ?

It happened a few times June last year and progressively got worse. As we were convinced it was a gas pressure issue and in fairness it did only play up once in a month after the gas pipe was upgraded.

As with all intermittent issues you think it’s cures till it’s not!

Nope the burners have not been touched.

 

[chris watkins]

his was checked by another gas safe engineer before as well. I remember him pouring water down there and stating there definitely was no issue on that side.

Oh well that blows me out of the water. 😕

 

[Navi Bhander]

Oh well that blows me out of the water. 😕

It’s the pipe that comes out of the bottom of each boiler that drips out water?

If that the case I remember the pipes being removed and water being put down the drain pipe that dissappears into the ground and out somewhere to make sure there was no blockage.

 

[Steve weightman]

Seems gas related...maybe dodgy meter governor..just a thought

 

[gmartine]

The system layout that he suggests is using the boilers independently, one to do the underfloor and one for the radiators and hot water tank. He wants me to get the accuweather or something on the boilers fitted but it makes the evohome system half redundant so will need to have a think.

Up to you, I expect his angle is that Evohome doesn't support true weather compensation which'll give the greatest efficiency savings which maybe fairly sizable for a large building. Yes Evohome has plenty of bells and whistles giving you the impression of control but it's really a fairly crude pseudo smart system. Go with the recommendations, if you really dislike the results or lack of controls it can be disconnected and your full Evo reinstated fairly easily I think (Check that with AM).

 

[ShaunCorbs]

tbh i would get the boilers running constant without problems first before you start messing with stats etc

even go down the road of simple controls for now

 

[Navi Bhander]

tbh i would get the boilers running constant without problems first before you start messing with stats etc

even go down the road of simple controls for now

I have been thinking this today.

What I don’t want for do is spend the money on separating the boilers, adding the low loss header, re plumbing everything and then still be left with the fault on the boilers.

I will get the work done asap but want the boilers up and running. What I don’t want is to do this and then find out there’s issues with the boilers, in that respect I’m better off biting the bullet and swapping to one correct spec boiler and save the expense of fitting and redoing the pipework again.