IMPORTANT : ALWAYS USE GAS SAFE REGISTERED ENGINEERS TO REPAIR YOUR BOILER
COMPLETELY DEAD
The boiler is not turning on and the pump / fan are not running at all and there is no sound of diverter motor running or spark generator sparking i.e. boiler is lifeless. In this case, the fuse at spur (boiler socket) and also fuse on the main PCB should be checked. If both fuses are fine (continuity using multi-meter or power check using electrical test screw driver) then the main control PCB is faulty and requires replacing.
Below are some examples of the part that needs to be replaced:
Ideal Isar/Icos HE range
Main Control PCB
Part No. 174486
Glowworm Cxi range Main Control PCB Part No.2000802731 Baxi 105E, 105HE Main Control PCB
Part No. 248074 or 5112380
Vaillant Ecotec Plus /Pro Main Control PCB Part No.. 0020052093 or 002013264
You can browse our shop under “Main Control PCB” category or use the search tool to find the part required.
NO DISPLAY
If the boiler is showing some life i.e. on power up some clicks are heard and the pump runs then it is possible that the display/user control PCB has become faulty. But this is not the only cause of “no Display”, other causes are :
- Interconnect lead which connects the main PCB to the User control/Display PCB is corroded or edge connectors are corroded
- The main PCB not supplying power to the display PCB
CENTRAL HEATING TURNS ON WHEN HOT WATER TAP IS OPENED
In combi boilers there is “Diverter Valve” which directs the heated water either to the central heating or to the domestic hot water heat exchanger (resulting in hot water to the taps). If the Diverter Valve becomes faulty then it becomes stuck in one position and cannot provide the correct function.
Below are some examples of the part that needs to be replaced:
Ideal Isar/Icos HE range Diverter Valve Kit
Part No.173624 or 170998
Glowworm Cxi range Diverter Valve & Motor Part No.2000802731 Glowworm Ultracom/Flexicom Diverter Valve
Part No. 0020014168
Baxi 105E, 105HE Diverter Valve
Part No. 248061
Vaillant Ecotec Plus /Pro Diverter Valve
Part No.. 0020020015 or 0020132682
You can browse our shop under “Diverter Valves” category or use the search tool to find the part required.
BOILER GIVES OVERHEAT ERROR OR RADIATORS FAR FROM BOILER NOT HEATING UP
As soon as the boiler is turned on for Heating or Hot water the pump should run. If the pump is jammed then it may result in an overheat fault. If the pump is ‘weak’ then the radiators far from the boiler will not heat up as the pump cannot circulate the water properly.
You can browse our shop under “Pumps” category or use the search tool to find the part required.
FAN FAULT
When ever Hot water or central heating is demanded the Pump and then the Fan should run (exctract the fumes from the burner). If the main control PCB senses that the Fan is not running (usually via the air pressure switch/sensor) then it will give an error code and stop the boiler running.
You can browse our shop under “Fans” category or use the search tool to find the part required.
FAIL TO LIGHT (FL)
On the the Ideal Isar boilers this is displayed as F /L flashing. This can be caused by following , listed in order of liklehood:
- Spark Generator faulty
- Main PCB Faulty
- Gas Valve Faulty
