Worcester Greenstar 30 HE Plus Boiler Problem

[andrewhall]

Hi Guys

Looking for some help / advice for the following - And sorry that its a bit long winded !

I have a Worcester Greenstar 30 HE Plus Condensing Combi Boiler
I do have the TR2 Thermostat connected.
It is about 10 years old now with no issues until now.
It has been serviced every two years or so without any issue

Hot Water is working perfectly and as normal.
The heating however is not - When heating is called for, the burner fires up for a few seconds, temperature rises a few degrees and then goes into Syphon Fill Mode. This is then how it cycles. No Fault Code is listed. Rads are getting up to around 40C at most.

Have read other posts that it could be the thermostat - The TR2 seems to be working perfectly but disconnected it and just ran the boiler from the text panel and still the same issue.

Have used the "Chimney Sweep" function and all rads heat up nicely - and stay on for the 10 mins or so that this function works for.

To me that rules out the diverter as the rads wouldnt heat if that was the problem.

Must add at this point that I am in Rural West Ireland so getting a good Gas Service Engineer is a problem (And no chance of Worcester themselves). The company i did use has gone bust so I found another company that did Nationwide Service.
So Before this issue arose, I arranged a service by these guys - Who came out and serviced the boiler, left me the cert and now I have this issue.
They are saying that it wasn't the service and that its probably "Sludged Up"
And if they come back out and not service related will charge me €80 per hour to fix (+ Parts). I've been 5 weeks trying to get them back now but they are saying that they will let me know when an engineer is in the area.

Is there a setting or something that this engineer could have changed (And not changed back) that would cause this.

As its summer, this isn't a huge issue but as soon as Autumn Winter comes upon us, this will be.

Any help/Ideas on the issue would be appreciated.
If the problem isn't service related, I don't mind getting someone else in to do the job - But don't want to be ripped off

Thanks

Andrew

 

[petit_pablo]

Syphon fill mode can be caused by a power interruption, faulty board, loose connection or oddly, faulty pump.

Have you run the CH for 15 minutes continuously? Thats how long syphon fill mode will run for before it goes back to normal.

HW demand wont clear it and chimney sweep mode over rides it temporarily

 

[andrewhall]

Thanks Petite Pablo for the info
Siphon fill mode is only kicking in for 1 - 2 minutes then going back to the burner coming on for a short period and back to symphony fill mode again
Have left it cycle like this for an hour but still no change
Is there anyway I can narrow down the problem ?
Thanks
Andrew

 

[andrewhall]

Just got a mail back from Worcester - They think most likely is the PCB is malfunctioning and needs replacing. Looks like it might well just have been a coincidence with the service.
Hope this helps anyone else who might get the same issue
Thanks
Andrew