Vaillant F78 Fault?

[SomebodE]

Hi all,
I'm new and was hoping for some advice.

We had a Vaillant 637 boiler installed last year with a Aurastor 260L (solar coil connected to boiler loop via a piece of pipe but allows future upgrade, suggested by Vaillant phone support) prior to a loft conversion. Also have a VR65 wiring centre and VRC 470f controller.

I know it's a large boiler and it was a throw up between the 630 and the 637 - we opted for the 637 as the difference was about £80 total.

Everything has been working normally since installation aside from the pump running occasionally - no demand indicators show, burner not firing and it does it every 10-60 mins when there is no demand. Is this normal?

It recently had it's first year's service and there was a "F.78 Fault DHW Sensor disconnected" fault code registered under the installer level. I was asked to register this with Vaillant under the 7 year warranty. Can someone explain what it means? Should I be concerned?

Is this something inside the boiler that Vaillant need to look at or is it outside that a competent person can look at?

Thanks in advance!

 

[spike.gb]

If you have used a Vaillant control system it could be a configuration error between the components.

 

[SomebodE]

Hi Spike,

Is this something that Vaillant will sort out under the warranty or will they refer me back to my installer?

The installer left me with the codes for getting into the installer menus of the boiler and the 470f - Is there a setting I can verify ?

 

[Ermintrude]

You can't get gas appliance advice on here if your not a member of gas safe.

But the issue is internal and will require a visit from a suitably qualified engineer. Make sure u tell him the issues your having as he may need parts

 

[SomebodE]

You can't get gas appliance advice on here if your not a member of gas safe.

But the issue is internal and will require a visit from a suitably qualified engineer. Make sure u tell him the issues your having as he may need parts

Thanks Ermintrude. I'll do that since you've said it's internal - I'll log it with Vaillant as it's got a long warranty. I had hoped it was something simple after Spike said configuration was a possibility.

Can I get information on what causes the code or is that classed as advice also? I'm not being rude, just new and don't know.

 

[Reg Man]

Its an accessory wiring configuration fault. Get a GSR and electrician who can read a wiring diagram to rectify fault.

 

[SomebodE]

Its an accessory wiring configuration fault. Get a GSR and electrician who can read a wiring diagram to rectify fault.

Thanks Reg Man. Do you think it's something Vaillant will do under their 7 year warranty or will they ask me to get my installer (from a year ago) back to rectify?

 

[spike.gb]

I would contact the original installer if you are not qualified not only could you be contravening the gas safety regs if you have to remove the appliance case, you would also invalidate any guarantee.

 

[SomebodE]

Its an accessory wiring configuration fault. Get a GSR and electrician who can read a wiring diagram to rectify fault.

Since it appears to be working fine for so long, do you think there is an issue with waiting until winter is over when both Vaillant and my installer have more time in their diaries?

 

[SomebodE]

I'm only asking if its ok to leave it a couple of months as I'm based in London and my installer is based on the South Coast.

 

[Dotty]

If you're not getting any grief you should be able to leave it for now but I'd wait for one of our Vaillant specialists to confirm that or tell me I'm a numpty.

Either way give your gsr a call, make an appointment and don't let him forget.

 

[SomebodE]

No grief from the system - in fact, had they not told me during the service, I would be none the wiser!

The GSR Installer hasn't returned my call.

A quick call to Vaillant in the week about it - was told to more or less call back in Jan as they have no one available to look at it now anyway.

 

[gassafe]

A quick call to Vaillant in the week about it - was told to more or less call back in Jan as they have no one available to look at it now anyway.

vaillants legendary after care service... They would probs only come & take a water sample anyway and avoid all responsibility...

 

[SomebodE]

I'd hope that wouldn't be an issue in a system boiler circuit with Fernox F1 in it.

 

[SomebodE]

I thought I'd report back for anyone else that had the same issue and perhaps get a little more advice as to where to go next.

Original installer declared himself bankrupt a left the country (!)

I had Vaillant look at the fault when they were replacing a gas valve under warranty. I have no idea what the engineer did but he did check a few bits on the PCB in relation to the F.78 and the cleared the fault.

I also had them check it again when servicing the boiler and it was just cleared as a fault from the log.

It was fine for a couple of months but the F.78 fault is back again.

Can someone give me any more advice?

As a reminder, I'm not gas safe registered, I have no desire or knowledge to open up a boiler but just a householder that wants to get the issue resolved in the right way 🙂

I have minor electronics engineering experience (used to repair monitors, computer power supplies, etc) so probably do something that doesn't require certs if pointed in the right direction.

Thanks in advance.

 

[SomebodE]

Alternatively, a recommendation of a Vaillant specialist who knows what they are doing and that can fix it plus is local to NW London would be useful 🙂

 

[Riley]

Thanks for feeding back

It might be worth posting in the it might be worth posting in the I'm looking for a plumber/heating engineer section of the form

 

[SomebodE]

Thanks.

Posted under http://www.ukplumbersforums.co.uk/i...ecialist-nw-london-remedy-f78.html#post815753

 

[Dotty]

For you this thread is over.