vaillant ecomax 824 f20 fault

[purplegerbil]

Hi, i have a vaillant ecomax which is showing an f20 fault code. This is something to do with overheat.
It has been like this for the past week so no way it is overheating as it has not worked. The code will not clear so i am guessing it may be a sensor, i have bought one but do not know which one to change. I have disconnected the wiring to each of the three i can see in turn and connected to the new sensor in the hope it would work without having to actually fit it until i know which one is at fault (if any).
I have contacted several engineers, only one came out and he said he suspects the pump although this is still free if a little stiff. He was going to go away and research it but has not got back to me so as i do not need to touch any gas i thought i would have a go myself. I am perfectly competent.
Any ideas ?

 

[Tibbot]

Other than the user controls, the whole boiler is a gas product. Working on it is gas work.

 

[Agile]

I have contacted several engineers, only one came out and he said he suspects the pump although this is still free if a little stiff. He was going to go away and research it but has not got back to me so as i do not need to touch any gas i thought i would have a go myself. I am perfectly competent.

Any ideas ?

So you call an engineer to give you a free diagnosis just so that you can do the repair yourself?

You are not competent to work on gas appliances unless assessed for that.

Just opening the case is gas work because its the combustion sealed chamber.

Tony

 

[purplegerbil]

I have asked an engineer to diagnose it so he can fix it, he has not called back. The other three engineers i have called cannot be bothered to return my calls. I cannot find any other heating engineers in my area.
I don't see that i have any choice other than to fix it myself !

 

[Tibbot]

There are tens of thousands of gas engineers. Whatever excuse you choose to use, it's still illegal gas work unless you can prove competence. No-one can stop you but don't expect any advice.

 

[Agile]

So have British Gas and Vaillant both not responded to your requests to repair the boiler?

And in spite of complaints to both they still will not come?

I think not!

Tony

 

[purplegerbil]

I had not thought to try british gas or vaillant, i had only checked in the local ads and online.
Thank you for the advice.

 

[Agile]

They think they are the market leaders!

But for small problems like yours probably is a local independent would usually be cheaper!

Tony

 

[gazdaz36]

The sensors need to be fitted so they get an earth connection to give a correct reading

 

[ninjacat]

//www.diynot.com/diy/threads/sime-super-90-not-firing.426402/

How many boilers do you have?

 

[purplegerbil]

Just the one, if you read the post about the Sime boiler it says i am waiting on a new boiler being installed, very light use vaillant now fitted.
Anyway no-one i have contacted has got back to me yet, british gas are a joke so waiting on a vaillant engineer.
I have gone ahead and changed the ntc sensors anyway and they made no difference also removed pump head and found this to be free and clean (the guy who fitted it has done this, he says it is most likely because it has been sitting).
As this code appears as soon as the boiler is switched on (takes a couple of seconds, sounds like it makes a couple of checks or something) could it be something as simple as i have not pressed the correct button to clear the code or reset it ?

 

[purplegerbil]

Incidently when changing the sensors he also pointed out that the other 'engineer' that had a look had not closed the front of the casing properly.

 

[ninjacat]

Just the one, if you read the post about the Sime boiler it says i am waiting on a new boiler being installed, very light use vaillant now ?

Yes, did read that. Just a bit weird that it was posted early this February so this new boiler has just been fitted and should have a warranty and you should be chasing the installer. Surely the warranty is void if you start doing things yourself?

 

[snes]

I have contacted several engineers, only one came out and he said he suspects the pump although this is still free if a little stiff. He was going to go away and research it but has not got back to me so as i do not need to touch any gas i thought i would have a go myself. I am perfectly competent.

Any ideas ?

So you call an engineer to give you a free diagnosis just so that you can do the repair yourself?

You are not competent to work on gas appliances unless assessed for that.

Just opening the case is gas work because its the combustion sealed chamber.

Tony

Tony (or others) - not arguing, just puzzled re this Vaillant case business, which repeatedly gets mentioned on this forum.

When my EcoPlus was being serviced, I could see quite clearly inside the case - the burner/heat exchanger, pump, water pipes etc. Everything, in fact, was room sealed.

Going from that observation, surely the case is just a case? As I said, not arguing, just curious. Anybody?

 

[purplegerbil]

Just the one, if you read the post about the Sime boiler it says i am waiting on a new boiler being installed, very light use vaillant now ?

Yes, did read that. Just a bit weird that it was posted early this February so this new boiler has just been fitted and should have a warranty and you should be chasing the installer. Surely the warranty is void if you start doing things yourself?

As i said this one has been used. The guy who installed it has tried to fix it but cannot get beyond it being a pump, blocked pipe or heat exchanger. He's stuck as it all seems to be clear and working but still wont clear the code.
He has been back to change sensors and double check the pump at no cost but has pointed out it is second hand and may have been faulty before installation.