Just looked at an old vaillant turbomax. Set the boiler calling for heat and burner dosent light. So removed front cover and instantly sparks and lights for 30 seconds then goes out a few seconds later repeats lights 30 seconds and goes out.
The pumps ok and the fan runs, I pulled fan apart to check for obstructions blew through to venture from aps all seems clear. Checked continuity on heat stat all ok. Cleaned spark electrodes. Now its lighting for 5 seconds and going out cycling with 20 sec gaps. Im assuming its the air pressure switch as it lit when I opened it up to the air in the room. Ive got myself confused as every time I pull it apart it behaves slightly differently. I still suspect the aps. Any ideas or advice appreciated. Ta.
The pumps ok and the fan runs, I pulled fan apart to check for obstructions blew through to venture from aps all seems clear. Checked continuity on heat stat all ok. Cleaned spark electrodes. Now its lighting for 5 seconds and going out cycling with 20 sec gaps. Im assuming its the air pressure switch as it lit when I opened it up to the air in the room. Ive got myself confused as every time I pull it apart it behaves slightly differently. I still suspect the aps. Any ideas or advice appreciated. Ta.