A few component failures lead to a better understanding of how parts work or come apart,
other failures may be just interesting.
Used Airtronic D4 burner that we bought cheaply on ebay, no reason was given why it had been replaced. Disintegrating mesh and solid carbon deposits show the burner was probably already starting to fail. A D2 burner will be smaller but with similar construction. Burner faults can only be determined by substitution with a known good one. Full details and pictures are on the Burner Autopsy page.
Melted hose caused by a break in the inner core allowing hot air into contact with the plastic outer covering. Probably caused by being bent too often or too much. Sections of the inner hose fell apart during removal.
D2 new screen with one removed and taken apart, showing the screen has 5 mesh layers which can clog.
Soft pipe kinked blocking the fuel supply.
Another burner from a D1L. Damage to the main burner parts was not caused by dismantling.
The part on the extreme left had to be separated from the burner to remove the burner.
More detail of the above burner.
The metal has been burnt through.
D1L Heat exchanger which contained the faulty burner. Upper left is where the part with the fuel pipe fitted. That joint would have had to be broken to remove the burner. Picture shows the area behind the burner that is normally hidden and cannot be accessed for mechanical cleaning.
Airtronic D2 ECU double sided circuit board after sealant removal.
More details and pictures of this and other heater's ECUs on the ECU Autopsy page.
Simple items are usually not of much interest but they are just as effective in causing the heater to fail.
D2L faulty Motor control board.
Original fault cause was the connector with the brown wires. Here all the six soldered connections to the circuit board have broken. Over time cyclic thermal expansion and contraction plus vibration cracked the old soldered joints. There was also evidence of corrosion on some connectors. The brown stain and blob was not significant.
Corrosion in barrel type fuseholder.
Oxidised wires causing bad connections.
Wires stripped back more than 50mm still oxidised.
Bright copper on some wires caused by wire strippers.
Badly clogged D1LCC Glowpin screen. Much of the surface carbon broke away whilst removing. Bending damage done during removal.
New screen lower right.
New exhaust silencer and one clogged up with white deposits.
Full details and pictures are on the Silencer Autopsy page.
Photos John Martin
The case of this D2 was crushed causing it to touch the impeller resulting in a severe overheat lockout. The overheat sensor (next photo) was damaged but surprising the ECU survived as did the blower except for the loss of it's magnet, replaced for £0.99 from ebay. See Blowers page for repairing blower motors.
The faulty combined sensor left with its replacement right. The wiring terminals on the sensor sensor show it must have been mighty hot. The faulty overheat sensor is the red-brown glass diode type package center top, its wires are also blackened.
Novel exhaust port repair using a socket spanner shown on a Russian site!