Vaillant ecotec plus cycling on HW only demand

[scoobydo123]

Gaswizard not questioning you but are you 100% certain on a 428 that d.0 in software should not reach 30? So assume if factory reset is performed the PCB loads default values for all adjustable values from its EPROM taking into account what d.93 is set to?

 

[gaswizzard]

Gaswizard not questioning you but are you 100% certain on a 428 that d.0 in software should not reach 30?

Quite sure , gas rating at d.0 28/30 will give you the answer (time gas meter) , a 28kw boiler is a 28kw boiler , no way could d.0 alter this unless the software has been tampered with.

So assume if factory reset is performed the PCB loads default values for all adjustable values from its EPROM taking into account what d.93 is set to?

Factory reset cannot change d.93 , how would the software 'know' what boiler was which considering you've programmed a different DSN.? , F70 will promt for a dsn if the board 'forgets'.

 

[scoobydo123]

Wondering now if I have the wrong PCB! Is the PCB the same across the ecotec plus range i.e. open vent and system. Likely as some parameters are clearly not available for the 4 series. Seriously if you have found the issue I will be sending you some beer tokens.

 

[gaswizzard]

Scooby my post was not about finding the issue but more so regards safety , make sure that d.0 is set for a max of 28 before you start the boiler.

Beer tokens

 

[scoobydo123]

Dont worry before I left it was set to what it was before. But if you are 100% that 28 should be the max if PCB is behaving normally then you have earned yourself a few pints. Even if I have to buy a new PCB then you have saved me so much time.

PS here is the link to Vailliant site and the PDF for the open vent series that contradicts what came with the boiler.

http://www.vaillant.co.uk/stepone2/...plus_open_vent_installation_and_servicing.pdf

 

[UpgradeME]

Is the PCB the same across the ecotec plus range i.e. open vent and system. Likely as some parameters are clearly not available for the 4 series.

The 6xx and 8xx range although have same/similar firmware have a different revision of system PCB (there's a number of physical changes). If you take a photo of your's with a clear view of it I can probably tell you!

How old is your boiler btw?

 

[mickyg]

sorry only just saw this thread, D0 on a 428 will default to 30kw. dont ask me why.

 

[UpgradeME]

Quite sure , gas rating at d.0 28/30 will give you the answer (time gas meter) , a 28kw boiler is a 28kw boiler , no way could d.0 alter this unless the software has been tampered with.

I agree with the meter for a definitive check, however with the figures OP has provided, a flow rate of 17.54 l/m and 30kW means the ΔT = 24.5°C with 28.2kW the ΔT matches OP's figures of 23°C

 

[scoobydo123]

Mickyg thanks for that, thought he had cracked it. I know you are very experienced in Vaillant can you confirm if the behaviour of ignoring d.0 during the first 50 seconds is normal? How do you get round it as I can only get a 4 second burn after the initial. Don't expect you to read the whole thread but struggling here.

UpgradeME installed 2008

Tks

 

[gaswizzard]

Have you got the original manual? , 2006 state a DSN of 2 and 2009 state a DSN of 13 , has the boiler had a new board at some time? , do you know the history of this boiler? , has someone changed the DSN?

Get that pump fitted.

 

[UpgradeME]

Don't expect you to read the whole thread but struggling here.

UpgradeME installed 2008

er, I think you missed some punctuation there! (wasn't installed by me!)

Scooby, several Vaillant (and other) RGI's have provided you with advice, I have provided you with some facts based on the tests you have carried out. So far, the initial diagnosis by everyone has yet to be disproven. The facts are your 28.2kW boiler is designed for a flow rate of 20 litres per minute which will give you a ΔT of 20°C.

Your system is not installed to the manufacturers specification so therefore is not performing correctly. Everyone from the start has advised you that flow rate could be an issue, we have proven that your flow rate is below specification. Fit the 15/60 circulator and then come back and tell us if it works or the new symptoms!

 

[scoobydo123]

Boiler was new when fitted will check date in the benchmark log book. It has had CP12's every year (rented property) since fitting but I have not always been present during these so someone could have done a swap. I have never changed the DSN but during these visits who knows. I have never reported a fault so no requested board change.

How can they change DSN's when only one revision of board (according to vailliant however there tech support has been quite lacking).

Sorry for the punctuation that was quite bad of me

Yes will get the pump installed when it finally turns up

 

[scoobydo123]

Pump still not turned up! Meanwhile who wants to bet that the pump is going to be the magic cure. Still not got 100% confirmation that under normal circumstances (ie 20l pm and delta of 20) if d.0 is ignored for first and subsequent burns.

 

[Agile]

What you experience for 50 sec has been noted before on this forum.

Many/most/all of the people replying see/install these boilers with Vaillant controls which take over the operation of the boiler.

It does not seem to affect all of that model so perhaps only on certain issues of the PCB.

However, regardless, that aspect seems to have NO bad effect on your boiler's operation and you get a long continuous burn.

The micro firing might be as a result of non optimum settings of boiler flow and cyl stat. In spite of several requests from me I have still not seen any firm data on those aspects.

But the boiler is heating the water as required and as far as I can see there are no user concerns apart from you not being happy with what you see when you watch it.

Tony

 

[scoobydo123]

Tony cylinder when satisfied (which takes ages due to micro firing) is currently set to 60c, I drew some HW off, and this measured just over 62c. If I could nail it down to a particular PCB/ software revision then I would be happy. Are you saying that micro firing is not bad for the boiler or affecting gas usage? Also remember it is also happening on CH so would imagine that this is only going off when timer on stat is switching off rather than being satisfied.

Thanks