Vaillant ecoTEC plus 428 CH won't fire

[Lorcan64]

Hi,

F and E system - Vaillant ecoTEC Plus 428 boiler.

Drayton Water and CH timer

Grundfos pump

2 x Honeywell 2-way diverter valves

Salamander pump (Not sure what that pumps tbh)


3 Storey house - 12 radiators ( 4 groundfloor, 6 first floor and 2 on the second floor, 1 bath, 1 shower). Tads have TRV’s and have been bled.


Not sure how many issues I have but here goes:

Main issue - if you turn the CH on using the Drayton timer the boiler won’t fire. If you turn the HW on via the timer, wait for about 30 seconds the boiler fires then you can turn the central heating on and away it goes except the groundfloor radiators don’t heat up (2nd issue). Sometimes the pipes leading to them get luke warm but not usefully so.


If I leave the hot water on and CH for a while and then turn off the HW the GF radiators begin to get warm.


I put the pump to 3 and that appeared to cause the radiators to heat up a bit more downstairs but again not usefully so.


I’ve looked at the 2 way diverters. When everything is off the lever stays to the left (away from the manual setting) when things are on the lever doesn’t seem to move from this position. Again when the system is off there is resistance when I gently push the lever toward the manual setting, letting it go it springs back its starting position. When the system is on the lever on both valves can be pushed to its opposite end with no resistance.


Not sure I want to leave the valves in manual.


The system has worked in the past.

Many thanks in advance.

 

[picasso]

The microswitch in the central heating zone valve is not making contact when the valve opens, new actuator head will sort that problem, press the I button when the boiler is running for c/heating and post back the s code shown.

 

[Lorcan64]

Thanks so much for the speedy reply. S.30 was the code on the display to begin with. If I put the HW on and NO CH I get an S.4 with the rad icon on the display. An S.2 if the CH on but HW off after putting the HW

on to for the boiler.

I notice that the pump seems to stay active for at least 5 mins once everything is off. Is that normal?

I have uploaded a picture as I'm not sure which valve could be the culprit.

 

[picasso]

The pump overrun is normal, I have marked the valve head you need to replace.

 

[Lorcan64]

Once again thank you picasso much appreciated. I'll try to get an electrician/engineer to sort.

 

[Lorcan64]

Update: Vaillant engineer came today and was 99% sure it was the valve, he even got one from his van however it turned out to be the relay on the timer so he swapped it and the valve opened. Job done you would have thought. He was booked in to do service and discovered the filter was clogged with 'gunge' Took a sample and is sending it off for analysis

He reckons that the heat exchanger et al will need to be replaced and the system drained and flushed depending on the water results. He says the boiler is only working at 7kw and not the 28 it should be. The boiler gives an S.53 every time it fires up telling itself to just fire at 7kw????

Bottom line he reckons probably a new boiler because of the 'damage' to the boiler components and so many will need replacing and do the flush then rather than flush it now then replace the boiler. Whoa is me .