Vaillant 824 TurboMax Plus How Water Issue

[Ramses505]

I have just started having a problem with the Hot Water supply - it now only seems to supply really hot water if I have the heating cirtcuit running first - If I turn on a HW tap without the heating on (and running for a minute or two) the water comes out only just warm. Boiler is 5 years old. Without a lot of knowledge I suspect that this might be due to the HW thermostat ? Any suggestions welcomed.

Thanks

 

[CorgiIOW]

Diverter Valve, is the most common fault.

Dave.

 

[Ramses505]

Dave,

Thanks for the reply - would that explain getting hot water only when the CH is running - doesn't the DV operate in both cases ?

Thanks

 

[CorgiIOW]

Yes, common fault , also APS , but thats not a problem for you at the moment.

Dave.

 

[Ramses505]

APS ? What is that ? Any idea of a rough cost of repair ? Thanks for the input Dave.

Regards

 

[CorgiIOW]

APS, stands for Air Pressure Switch.

Its too much really to explain, plus its "critical" as to the way your boiler works, best leave to a Corgi chap.

As for cost, the part is readily available, and not hard to change, maybe others on here can give you some guidance to that question.

Locations seem to make a difference.

Regards

Dave.

 

[Ramses505]

Incredible service on this forum !

Thanks for that Dave I will call a man.

Regards

 

[Agile]

The symptoms of a failed diverter valve are very clear and for that matter so is a failed APS.

The description given does not match any common fault on this model.

Either its being described wrongly or its a completely different ( and interesting new ) fault.

Tony Glazier

 

[CorgiIOW]

Tony, you have know woken me up,, LOL.

So what are you thinking , you have "Me" wandering now !

Dave.

 

[Agile]

I was thinking that the Peugeot place on the road just south of Skyblue Way has already been dug up and it seems that housing is being started like next week!

Quite sad really.

Dont see much evidence of any financial hardship though. Many new firms moving into City. Even Nat Grid Transco have a call centre there!

Tony

 

[CorgiIOW]

, , ,

 

[Ramses505]

To restate the symptoms -

If I do NOT have the heating on - I turn on a HW tap and the water does not get hot, only warm. If I then turn off the HW tap and turn heating on via the timer (1 hour CH demand) then wait a minute or two and then turn on the HW tap, water gets hot like it used to do.

To clarify, I am not just getting the first 'flush' of hot water caused by the heating circuit having been run, but continuous HW to fill a bath.

Yesterday it was like this all day - but today I filled the kitchen sink with HW without running the CH first.

Looking back I think this has been happening for a while now (maybe 1 month) on and off - sometimes I have assumed that the water pressure was too low (a neighbour maybe) - however after further thought I don't think this was right as without sufficient pressure the boiler won't light at all.

Hope this provides enough info and thanks for all the input.

Regards

 

[Agile]

As I said before, this is not an obvious logical fault condition.

It may be a combination of two faults or it may be a logic fault on the control PCB which is providing a wrong temperature selection for DHW.

I expect that unless anyone else has encountered exactly this same problem it will need a competent engineer to diagnose the fault on site.

Tony

 

[ChrisR]

Ramses505 did you get a solution ? I have a boiler with a similar-sounding problem.

 

[Ramses505]

No, I have not got a sloution yet, sorry. I am going to repost it and see what happens.