Vaillant ecoFIT pure 418 Honeywell T3R - S30 status code

[intamixx]

Hello,
I have a Vaillant ecoFIT pure 418 boiler and a Honeywell T3R wireless thermostat. A few days ago trying putting on the heating via the thermostat and noticed there was no activity on the boiler but there was an F23 error.
Gas engineer came out and said there was trapped air in the rads and the pump which he resolved. He mentioned the pump looked healthy and heating in general was functioning well.
Checked the T3R receiver box in the airing cupboard it was showing a green light. The wireless icon on the thermostat was showing as connected. Did a re-pairing of the 2 just to make sure it was ok and changed batteries for brand new ones.
Got a few S02 status codes on the boiler after he left so he came back and had another look.
Now getting and S30 status code. There is still the green light on the receiver and the wireless icon is displayed as per normal on the receiver. The flame icon on the T3R transmitter is showing, but there is no subsequent activity on the boiler. Does this point to a problem with the thermostat even though the lights / icons are showing good? So thinking maybe a replacement thermostat is required to eliminate it from the fault finding process, but is the T3R known for this sort of issue by any chance?
We do have a magna clean that was serviced about a year ago and the pump is a grundos one that is around 10 years old.
Basically to override the system I press the reset button on the boiler to make the call for heat. Pressing the button on the T3R receiver box does nothing.
Any advice would be greatly appreciated.
Thanks.

 

[CountryFan]

That's not how your thermostat works by the looks of it. The motorised valve isn't likely sending a switched live back to the boiler. Voltage testing would confirm this, however if you move the heating valve lever and resistance is felt then it's not opening, if it's floppy then could be opening but not making the microswitch.

 

[intamixx]

To my limited knowledge the heating valve is the one on the right in the pictures. So do I flip it to MAN then try making the call for heat on the thermostat? Would that be the next logical test?

 

[Johntheo5]

I can't see the zone valve but if its a Honeywell then opening the valve manually with the lever will not close the auxiliary (end) switch contacts to fire the boiler, others, including EPH will fire the boiler if you open them manually.

 

[CountryFan]

To my limited knowledge the heating valve is the one on the right in the pictures. So do I flip it to MAN then try making the call for heat on the thermostat? Would that be the next logical test?

Turning to manual doesn't bring the heating on. So if you did that and called for heat it would end in the same result as now

 

[intamixx]

They are indeed honeywell 2 way diverter valves.
So is the next logical thing to try replacing the diverter head for the central heating one and see if it makes a difference? I've had the plumber come out twice and because the system works when he is here, he can see nothing wrong.
I attach the T3R instructions for the button located on the device, which shows it can send toggle on / off to the boiler, if it is of any use to helping the cause.

 

[CountryFan]

They are indeed honeywell 2 way diverter valves.
So is the next logical thing to try replacing the diverter head for the central heating one and see if it makes a difference? I've had the plumber come out twice and because the system works when he is here, he can see nothing wrong.
I attach the T3R instructions for the button located on the device, which shows it can send toggle on / off to the boiler, if it is of any use to helping the cause.

Did you carry out any testing like I said in post #2?

 

[Johntheo5]

They are indeed honeywell 2 way diverter valves.
So is the next logical thing to try replacing the diverter head for the central heating one and see if it makes a difference? I've had the plumber come out twice and because the system works when he is here, he can see nothing wrong.
I attach the T3R instructions for the button located on the device, which shows it can send toggle on / off to the boiler, if it is of any use to helping the cause.

Does the boiler start up if you toggle that button on? (both zone valves OFF)

 

[intamixx]

The boiler starts up sometimes with the toggle button and with the zones diverter valves in the auto position.
Don't know how to do a voltage test, but pushing the lever over to the MAN position on the heating diverter valve, I can say there was resistance and the lever even started to move back across to the starting position once I had pushed it to the other side. So is this conclusive that the 2 way diverter valve has failed or in a stuck position? I would think my next step is to replace the actuator head.

 

[Johntheo5]

The valve is working fine mechanically, it will move back to the off position once you release the lever. If you want to keep the valve opened manually, (used for refilling the system) then you just latch in the lever by pushing it upwards after opening the valve.

Follow one of the leads back to its junction box and take a photo of the number and colour of wires from the valve.

 

[CountryFan]

Don't know how to do a voltage test

Time for an engineer then me thinks, rather than risk injury to yourself, as you should need to carry out safe isolation.