Ideal Mini C32 Boiler domestic hot water no central heating?

[lexx]

Hi,
The boiler fires up for dhw in both DHW only, and DHW+CH modes, but no central heating.
The green led panel indicator flashes for 1second OFF 1second ON in this condition.
When powering the boiler up after switching off the mains supply for a few seconds, the pump will run for about 5 seconds, the pin on the CH flow switch comes out and operates the micro switch.
When this happens the fan is not powered up.
After reading other post I put the boiler into diagnostic mode by changing the jumper position from pins 2+3 to pins 3+4. When the boiler is first turned on all 3 LEDs come on together flash twice at one second intervals, then only the left hand side green led remains flashing at 1 second intervals.
When the hot tap is opened both the green LEDs flash alternately.
I have made various checks as follows
No room thermostat fitted.
system pressure =1.5 Bar
Safety overheat thermostat closed.
Primary circuit flow switch operating OK.
CH and DHW temperature probes measure about 11.2k ohm @ room temperature.
Fitted a new diverter valve actuator. The actuator has 230VAC on terminals 2&3. Stays in DHW position.
The boiler has two pcbs, the honeywell ignition board has 230VAC on pins 1+2 when the DHW is running, but nothing when in CH.
The only thing I couldn't check out is the digital time switch. It appears to be o.K but not certain it is actually switching ON even though it toggles ON and OFF, I have no info on switch.
This is all a bit rushed,I hope it makes sense.
Any help appreciated.
Gary.

 

[Agile]

It sounds as if the diverter valve motor is not moving.

This can be a practical problem at the motor or the relay on the control PCB has an O/C coil or there is no demand for CH.

Check first to see if live moves between brown and black wires on diverter motor when a demand is placed on DHW or CH. Note this does NOT change just by moving the front panel switch, you need the relevant demand as well.

The blue wire is always neutral. But measure in respect of the chassis.

If you have fiddled with the clock connections the connector to clock must be connected correctly with red at top as the connector is not polorised.

When you have a demand for CH the outer green lights flash together.

Tony Glazier

 

[lexx]

Hi,
Thanks for the help.
Looks like the fault may have been the connector at the back of the time switch not seated correctly. I repositioned it and the boiler is working.
The clock appeared to be working normally due to the onboard backup battery
Cheers Gary.

 

[Agile]

How do you explain that getting disturbed when its inside the PCB casing?

 

[lexx]

Hi,
The time switch lead connector moved in about 1/4" when I pressed it in toward the time switch. I can only guess as to why it may have backed off.
Everything appears to be working fine.
Many Thanks.
Gary.