Vaillant boiler issues F28 on ecotec 430 not the normal culprit

[Riley]

Well quite. I guess it could be that too

 

[Aire]

What else throws up F28 in the depths of winter !!!
Could be if it is both or either, worth a check wouldn't you say?

Doubtful, he said he's been having intermittent issues for the last 9 months. Although there could be other reasons for that to be causing issues that don't relate to the cold weather.

 

[chris watkins]

Doubtful, he said he's been having intermittent issues for the last 9 months. Although there could be other reasons for that to be causing issues that don't relate to the cold weather.

I know it is not cold all year round but still produces, where does that pipe end up? Just a thought but would need to be on site.

One thing for sure 60kW's through 28mm ain't to clever & on U/F, rad mix, with no separation, another great design.

 

[Navi Bhander]

Also I hope op is not testing the mbar

Nope, plumber or cadent gas has been out approx 20-30 times now.....

 

[Navi Bhander]

Not withstanding the F28, it would appear you have a you have 2 oversized boilers on a poorly designed system, I take it from the single large pump that there is no low loss header installed? (60kW through 28mm what were they thinking !!!)

Why haven't you gone back to the installer / manufacturer before now?

When you go down to reset, is it both that show the F28 ??

The issue was the installer had said it was due to the low main gas pressure. cadent gas tookmonths of coming out and checking before they agreed we had spikes in pressure hence the reason the F28 was coming up.

They rectified the issue by installing a 63mm pipe to the house.

I’m not in the trade and hence had presumed that it was a pressure issue and left it at that.

Now the issue isn’t the gas pressure as they fixed this in December and in all honesty for a month it worked faultlessly.

As the weather has got better the issue has become more apparent again and is daily.

I’ve switched off one boiler and and currently searching for a recommendation for someone to come rectify this for us.

 

[Riley]

Nope, plumber or cadent gas has been out approx 20-30 times now...

Have to ask as you wouldn’t believe the amount of people that think they know what they’re doing

 

[gmartine]

I’m based in Northwood Middlesex. Is there any recommendations that someone can make?

There's a superb engineer and troubleshooter in your area called Andrew Millward of https://www.homecomfortassured.co.uk/ive

Just do what he recommends, as said already sounds like the boilers are well oversized so could possibly be a poorly designed system with no LLH.

 

[Navi Bhander]

There's a superb engineer and troubleshooter in your area called Andrew Millward of https://www.homecomfortassured.co.uk/ive

Just do what he recommends, as said already sounds like the boilers are well oversized so could possibly be a poorly designed system with no LLH.

I will give him a call and keep you updated. Thanks

 

[chris watkins]

I will second the post re Andrew, if anyone can Mr Millward can.

 

[Old Account]

Why do you need two boilers for such a system with 30 kw each running in the same time? As mentioned above to all the others well oversized and get a reliable engineer or perhaps donit via warranty

 

[Navi Bhander]

Why do you need two boilers for such a system with 30 kw each running in the same time? As mentioned above to all the others well oversized and get a reliable engineer or perhaps donit via warranty

I honestly don’t know, I have asked the subcontractors that built the property and they said they are variable output so will work load dependant or something along those lines.

Apparently the heat calculation for the house was 57kw and the space worked out best for 2x 30kw.

I’m not sure tbh but it’s been one nightmare.

I’ve had a various gas safe plumbers out, they all looked at the system and said it’s fine and it’s a gas supply to the property issue. I’m sure apart from cadent I’ve paid 3 local firms to come check it.

The last guy checked it and gave me a certificate to say it’s gas safe tested as well and said it’s a supply issue to the meter.

As you can see I’ve been trying to resolve this and was obviously fobbed off by everyone that it’s a supply issue to the house.

 

[Navi Bhander]

I will second the post re Andrew, if anyone can Mr Millward can.

I’ve spoken with him and he’s coming out tomorrow

 

[gmartine]

If you use Millward do keep us posted, thanks.

 

[Navi Bhander]

If you use Millward do keep us posted, thanks.

Will keep you updated tomorrow.

Just to clarify with one boiler disconnected the issue is still there on the remaining boiler.

When the controller demands heat, the radiator symbol comes up on the boiler, the pump switches on and after 5-10 secs the flame light comes on with the triangle variable display comes on on the minimum setting. It then switches off within 2 secs and then starts up again after 5-10 then continues to run.

It does this most times I look at it, I presume this is an ignition failure?

I understand the boilers may be missing headers etc and I will have this rectified. But I don’t think this or a bigger meter will fix my issue as even with 1 boiler I have the issue.

I’m really hoping Andrew comes in and works his magic, having spent 15 mins on the phone he clearly knows his stuff.

 

[Navi Bhander]

Just a quick update.

Had Andrew over today. Firstly I agree with the other recommendations, he is such a lovely guy and clearly knows his stuff.

To cut a very long story short he identified the lack of low loss header and isn’t convinced pairing the boilers together is the best way. As I have 2 Honeywell evohome systems to cover all the zones and 2 tanks he needs to double check how to integrate everything together.

However none of this is the cause of the F28.

He checked the pressure at each boiler, 24mb standing that drops to 18 on full load of both boilers when in chimney sweep.

He said that’s on the low side but not enough to give the problem I have.

The f28 is ignition failure and luckily it played up once while he was there. The boiler while having 24mb pressure fails to ignite on its first attempt, something it does on every other start up.

He checked the flue pipe, did various tests on the boilers, co2 checks etc and nothing at all.

He’s going to speak with a few Vaillant contacts of his to check as nothing is untoward but yet both boilers display identical issues even when each one is isolated.

As it stands in the past few days the F28 hasn’t come back with 1 boiler running, albeit it may not start on the 1st attempt.

Andrew has also advised to increase the pipe diameter to the boiler to 22mm instead of using a 15mm pipe from the 28mm pipe.

Any other suggestions to what my f28 fault could be?

 

[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.