Vaillant Time Clock Issue

[jrt]

Hi All

I have a vaillant eco tec plus condensing boiler.
All was well until my micro gyr timer clock seemed to go faulty.
The boiler was always calling for heat and water no matter what the timer said on/off etc.
I thought it must be the clock so i changed it for a siemens rwb29 programmer.
Guess what no change

It is still firing up all the time.
Have you all got any ideas?
many thanks in advance

Jay

 

[LIFES A GAS]

You clearly have a system boiler & not a combi if your using that programmer.
Does your boiler fire up when both heat & HW are turned off?
Does it still fire up when room & cylinder stats are satisfied?
If so then has any wiring in the house been altered?
I would suspect that a micro-switch in the diverter valve has stuck open and calling when there is no demand, have seen this a few times with Danfoss controls,
Hope this helps, Martin

 

[stevetheplumber]

Hi All

I have a vaillant eco tec plus condensing boiler.
All was well until my micro gyr timer clock seemed to go faulty.
The boiler was always calling for heat and water no matter what the timer said on/off etc.
I thought it must be the clock so i changed it for a siemens rwb29 programmer.
Guess what no change

It is still firing up all the time.
Have you all got any ideas?
many thanks in advance

Jay

quick thought y7ou dont have the warmstart switched on and you confusing this with boiler firing for heating ?
turn hot water stat to off position and then back to mid position see if this helps

 

[jrt]

Thanks for the help

The boiler is a 428 not a combi that is correct.

Not sure what warm start is?

I tried turning the water and heat dials down to zero and this worked.
As soon as I turn them up past half way it fires up again.

I thought when the clock is off not asking for anything the boiler should not fire no matter what is being asked for?

No wiring has been changed anywhere I am still confused?

 

[LIFES A GAS]

When you say you turned both dials to zero, are you refering to the dials on the boiler? if so what happens when you turn down the room thermostat(on the wall) and the HW cylinder stat (strapped to side of cylinder)? but leave the dials on the boiler up, only the heating one (bottom) does anything on a system boiler by the way.
Martin

 

[jrt]

Been doing some trials!

When I turn the dials on the boiler down to zero the boiler knocks off.

When i turn the heating dial up the boiler fires even with the room stat on zero.

The room stats and the programmer seem to have no control over the boiler

I have had this boiler a year and I am sure I would of noticed this before it cannot always have been like this !

 

[LIFES A GAS]

Based on what you are saying I would think it's either the diverter valve or the boilers PCB, you can check the diver valve by this method: turn off the power, remove the diverter valve orange wire from the wiring centre, turn power back on, with programmer off (heat & HW) is the orange wire still live, if it is then you probably need a new actuator or complete 3 port vale depends on make model. As I said I have come across this a few time with the Danfoss HSA2 & HSA3 valve actuators.
Hope this helps, Martin

 

[payney1974]

Sounds like a diverter valve fault but have you got a frost stat fitted ?