Vaillant ecoTEC plus 428 f27, f64 & CON error

[dipz]

Hi,

I'm having problems with my boiler recently, its about 8 years old. It's getting a f27 & f64 error code during start up but restarting the boiler will solve this and fire up however recently I've been getting CON error which means something is wrong with the PCB. This is mostly in the morning when its cold outside (around 5-10c). Whenever I get the CON error I open up the covers and use a hairdryer to heat the PCB board up for about 10 seconds, turn on the boiler and everything works as normal with no faults at all. Sounds weird but it works!

I want to know what parts could be faulty so I can replace them as I want to save the cost of replacing the whole PCB board, it seems like 1 or more components on the PCB are faulty as they start working with a little heat. I've focused the heat on 2 parts while covering the rest of the PCB board up and the boiler fired up so believe these could be faulty? Attached is the picture.

Thanks in advance!

 

[Agile]

I am afraid that on your boiler the front cover forms thee room sealed aspect that makes your boiler so safe.

Therefore the forum advice is that a DIYer should never open the case and that a Gas Safe engineer should be called.

If the PCB does need changing then a Vaillant fixed price repair may be the best value.

Tony

 

[dipz]

I've got a Gas Safe engineer under my business and its all been checked and its safe. Just trying to figure out a way of repairing the PCB instead of forking out a large sum to replace it.
thanks

 

[Agile]

Surely if you have a business with a gas safe registered engineer then you cannot be so short of money that you cannot afford a brand new PCB at about £170 ?

Do you pay him with peanuts?

He could move to British Gas and get about £35,000 per annum

 

[gazdaz36]

I think you'll find that on a vaillant 400 series you can get to the pcb without breaking the seal to the air box Tony

 

[muggles]

I've got a Gas Safe engineer under my business and its all been checked and its safe. Just trying to figure out a way of repairing the PCB instead of forking out a large sum to replace it.
thanks

The PCB provides vital safety functions and shouldn't be tampered with. I would doubt that anyone will know what might have failed on the board as it's not something we'd investigate - the whole board would just be replaced, which is what you should do along with having the underlying fault investigated

 

[DP]

Dipz, where did you get the idea the hairdryer hot blast on the marked components gets the things moving along. The round thing is a capacitor and boxy component a transformer. Now that you know what the parts are, where are you going to source these parts and how are you going to change these. Do you even know what these components do in that position and what function that area performs?

 

[stardanny]

I think you'll find that on a vaillant 400 series you can get to the pcb without breaking the seal to the air box Tony

The front cover need to be removed in order to access the PCB

Daniel.

 

[DP]

The front cover ie the big white cover does not reveal the combustion chamber if we are going to be splitting hair. Two torch screws allow the white lid to be lifted and pcb housing drops down. At all times the verboten area stays sealed not that the interested party could do any investigation with a hair dryer . As said earlier by another poster, pcb, can be eye balled without going into the combustion chamber.

Why anyone would want to start straightening cats wiskers with a blow lamp is beyond belief, especially when a supposed gas engineer is a phone call away. Further conundrum is why play hot air on a pcb when you have a RGI available unless he is more than useless

 

[Emu13]

I've been experiencing the exact same problem with F27 and F62 errors occurring. To remedy the problem i simply pressed the resent button and normally cures it. However, last Friday even that didn't work and after reading you post tried the hairdryer trick and it worked.

I suspected the problem to be the pcb and after changing it it worked with no problem. On further examination of the old pcb my suspicious were correct as one of the capacitors was leaking and smelt odd.

I've taken a picture and you can just see the brown staining at the base of the capacitor.

 

[snes]

Post deleted - no longer applicable.

 

[DP]

Red thingy to the right of said capacitor as well as the black component right top corner of PCB has similar staining

How do you know the red thing is not the cause of it.
If I am correct, as this item is similar to those used on other boards, is know as a fuse

 

[Emu13]

Well it could be. I just had another look and although it's difficult to see in the photo there is more staining round the base of the capacitor. In fact, there's slight staining around the identical capacitor on the left. Whatever caused the fault I wouldn't trust the job done by only replacing the component in case the IC's are damaged. Who's knows an 'unstable' capacity maybe causing the IC to be erratic.

Hope this helps

regards

 

[DP]

Emu did you meter the capacitor to see if the value matches the markings?
When you are diagnosing faults, it is a logic based process, not based on assumption

 

[Emu13]

I didn't check the capacitor rating and my logic was based on the fact that the brief application of the hairdyer on the pcb fixed it.

I still have the old pcb and will check the capacitor and get back to you.