Buderus GC144 issues

[MH10]

Have a 7 year old Buderus GC144 acting up. Had a tech out a couple times and still no fix.

Its currently stuck on recycle, it calls for heat -> boiler pilot and igniter lights flame -> main burner runs for an intermittent amount of time usually 4-10 seconds -> clicking (relay?) turns main burner off -> repeat. If I leave the outside door open as it’s a couple feet away, I can usually get a minute or two before it throws the recycle. When it does run it’s putting off a lot of condensation within the chimney too and the exhaust if quite foul smelling.

I’ve had the pilot burner replaced, air/fuel settings adjusted, bypassed vent damper and flame roll out switch, verified good 24V supply, tightened all electrical connections, took the Honeywell 8600h burner module apart and checked for burn marks or broken solder joints but looks all good.

The Honeywell blinks 3 times for recycle code which indicates “flame failed during run”. Is there anyway to bypass this as I think it’s based on a current reading only? Any other voltage readings I could take during operation sequence?

 

[Fitter30]

Was the burners pulled and cleaned when pilot was replaced? Is there a ground wire from controls ground burner terminal? If the flame stinks it probably burning rich - lazy yellow, sooty. Here a manual.on the burner control. 97k btu boiler?

https://www.google.com/url?q=https://www.cyb-tec.com/S8600_2010.pdf&sa=U&ved=2ahUKEwi1tv_xwoqFAxXFk4kEHX53C60QFnoECAMQAg&usg=AOvVaw1jPaSFl_F2rTO4bbin-3cr

 

[Sponsor]

 

[MH10]

Ah that manual is much more detailed than the one I found, thanks.

Burners weren't previously pulled so I went ahead and cleaned them, quite dirty from all the condensation flue issues.

There is a ground run from the (GND) Honeywell S8600H to the gas valve, the manual mentions a ground to the pilot burner (igniter beside the burner I'm assuming?) but I I don't believe the actual pilot burner has a ground wire as there's never been one on there, just the spark ignition wire. The gas valve has actual male ground prongs to connect on to.

I think I might try replacing the S8600H with a new S8610U.

Adjusted the pilot flame with the pilot adjustment screw with no change.

I measured 3µA following the spark igniter troubleshooting guide so no issues there. Based on the pictures, do you think replacing the whole igniter assembly would have any benefit?

Was thinking maybe running a separate source feed to the boiler just to eliminate any ground issues as all the grounds tie back in at the Aquastat to the source ground.

I'm getting the gas utility to come check the incoming regulator on the house to rule that out.

 

[Fitter30]

Pilot is petty nasty replace it. The ground wire should have a cloth type insulation radiate heat will melt other types.

 

[MH10]

Ran separate ground and tested all ground with ohm meter - No fix
Replaced S8600H with a new S8610U - No fix

Jumpered 24V directly to gas valve, this worked and allowed the boiler to stay running, was hoping the issue was in the S8600H but it appears not. What else is there left to try and replace? Gas valve itself? Based on the S8600H manual it has the Honeywell VR8204 gas valve (found this Honeywell VR8204A2076 Electronic Gas Valve on amazon as that's only place could find it.)

PIlot flame is quite noisy, tried adjusting the set screw and it didn't make any change from what I could tell.

 

[Fitter30]

Burner smelling the flame has to look yellow and might be pushing out. Look at flame see if the pilot flame is steady when burning. Take some pics of the boiler, flue and flue sticking out of the roof.

 

[MH10]

See the attached link for the flame start up and shut down

https://imgur.com/a/KEGFwat

See attached link for the boiler pics

https://imgur.com/a/VmuDCFX

 

[Fitter30]

That pic of the burner think you might have a compromised boiler section (leak). By the way the flame disappears. Take the operating thermostat from where it's set turn it up to 205°. When it gets to that temp turn pumps off and listen for the sizzle of water leaking flashing to steam. Shine a good flashlite in that burner cavities. No other burner changes?