Vaillant EcoTec 831 Diverter Valve - Can’t replace it?

[CBW]

Did the thermostat work before these problems?

Edited message: Just checked compatibility, and guess what yours is compatible according to Netamo:

 

[Jaunty]

Did the thermostat work before these problems?

Edited message: Just checked compatibility, and guess what yours is compatible according to Netamo:

Thanks and just to confirm controller was 100% fine before leaky diverter valve

 

[Jaunty]

As @The Novice , I am not familiar with your Netamo, I have read about them but never seen one in the flesh, some manus do not support third party controls , but if this was the case they should have removed the external controls and returned the boiler to factory settings , restoring heat and HW, it is then up to you to sort that from there on , it is simply a matter of removing two wires isolating them and fitting a link, ten mins job at most

Thanks. That’s what I thought - at least leave it so we can do manually!

 

[Jaunty]

So back home and no heating but have hot water at least. Wife spoke to Vaillant who were less than helpful saying it looks like the Netatmo controller is requesting hot water not heat?!

Apparently the engineer was here under an hour and just wanted to get out ASAP. No details of what work was done have been left. Anyway the Netatmo controller seems fine to me. I’ve linked a video of it on Youtube responding to commands and the boiler responding. Any clues as to why we may not have hot water, before I follow up with Vaillant again?

Thanks again to those that are helping it is appreciated.

 

[CBW]

Put heating on and press the i button and respond on here to what it states.

 

[Jaunty]

I’m no Steven Spielberg but see video. In brief:

Radiator sign comes on. Burner sign comes on for a short time then goes off. Rad sign flashes then come on steady. The info sign shows 5. On the left and a 4 on the right.

edit per Novice comments: S.4 then S.7 in info

 

[Jaunty]

More info! This is all that seems to have been left behind. So could it be rather than change the leaking/faulty diverter valve, they’ve just repaired the leak -

but the valve is still faulty and not switching between hot water and heat?

 

[CBW]

Ok so the burner is lighting, (S.4) and then after so long goes into pump overrun (S.7). Do you have any zone/motorised valves? Are the big pipes underneath hot at all? Check the isolation valves underneath, post photo if possible. I thought you had hot water?

 

[Jaunty]

We have hot water but no heating. Off to work now so will try and makes sense of this and report back.

 

[Jaunty]

(What I’m wondering is if the diverter valve was not changed and the solenoid is sticking could that explain the problem?).

 

[CBW]

Can't see it, but wouldn't rule it out. Check out stuff in my last post and we'll go from there.

 

[Jaunty]

I will check the things you ask about when I get home. Is it reasonable to say that the Netatmo is not the problem here, and a fixed price repair with all parts and a service included should give us heating and hot water?

 

[ianmcd]

I will check the things you ask about when I get home. Is it reasonable to say that the Netatmo is not the problem here, and a fixed price repair with all parts and a service included should give us heating and hot water?

yes tell them you want a senior engineer

 

[Jaunty]

Update to all - I spoke to Vaillant and reiterated it wasn’t the controller and offered to send them a video. They agreed to send another engineer, who came today and got us going in 10 minutes. Apparently there was a loose wire in the boiler.

Thanks all for the input. Whilst a bit of a palaver due to Vaillant, we avoided the need for a clearly unnecessary new boiler. Cheers all.

 

[Lee Edwards]

Yes I work on EcoTEC pro’s almost everyday (same layout as 831) and changed many a diverter Both brass and plastic, and like @ianmcd said, not seen one that can’t be replaced. The backrail (holds all bottom parts together) can be renewed, but any screw that’s rusted on I use either a screwdriver and gently tap with hammer to get a bite or my impact screwdriver. Screws can be rounded off, but can be drilled out and renewed.

Hopefully Vaillant will sort it for you

Hi. Can you tell me what size drill bit you use to drill out the screws as I have one where the screws have rusted and I cannot get them to budge. So need to drill them out. Also, can you recommend some nice long length screw drivers as I am in need of a new set. Thanks