Ideal Standard H18 - - on display

Discussion in 'Plumbers' Talk' started by, Dec 4, 2018.

  1. New Member


    My daughter has just got her new house. Boiler was working ok but a week later we have been presented with 2 dashes "- -" on the display and heating appears not to be coming on.

    System is typical 'system boiler type' with Boiler (Ideal Standard H18, 3 port valve, cylinder, rads etc).

    Ive checked that from programmer the system is calling for heating and or hot water, 3 port valve motors and pump runs, signal present at boiler.

    The manual suggest that dial 'B' is in off position (boiler off) but its not, its rotated to on position.

    Have i missed something or is it time to call CH Engineer.

    Many Thanks

  2. Mike83

    Mike83 Well-Known Member

    Could you confirm the boiler model.
    The Teach likes this.
  3. The Teach

    The Teach Well-Known Member

    They make toilets :(
    KIAB and Mike83 like this.
  4. New Member

    HI Mike

    From the front panel it Has Ideal Logic+ H18


  5. The Teach

    The Teach Well-Known Member

    Could be a number of defects,first check would be to turn it off electrically then power up. Wait 4 minutes and see what happens.

    The mode knob may have a snapped spindle although visually the knob front is pointing in the correct direction the rear part could in an off position.
    Could be a few problems,not ideal :( Easily repaired by an Ideal expert.
  6. New Member

    Yes, we did this already several times, the old reboot. It goes through its start up sequence and displays as follows:-
    All display items on,
    Displays H
    Displays n
    Displays 18
    Displays 11
    Displays --

    The mode knob feels nice and positive so I don't suspect that, but of course its a possibility and thanks for the suggestion will try and check this.

    Typical its just out of warranty installed about 18 months ago......

    I'm beginning to think its faulty PCB / motherboard.


  7. New Member

    Engineer coming Saturday so hopeful he can diagnose.


  8. KIAB

    KIAB Well-Known Member

    Do update this thread as to what is the fault.
  9. New Member

    So the engineer arrived but thought it was the 3 port valve, had already eliminated this as it was giving a 240v back to boiler to say I want heat. He suggested that the port itself could be stuck inside so boiler would fire and shut down quickly, unfortunately this wasn't happening and like i said according to the display boiler was switched off. He took the head off and tried it like that but made no difference.....

    So, i recalled the post above about the switch and with the engineers agreement we removed the PCB and edge connectors and i reconnected the board and sat it on the plastic housing and turned the switch pot with small screwdriver, voila boiler display went from the 2 dashes to displaying the temperature. So either one of the edge connectors wasn't connecting properly or there is something amiss with the switch to turn on and off. We have to revisit the plastic turn switch to see why it's not positioning correctly but left it working for now. Strange that the switch is not actually a switch but a pot (variable resistor).


    KIAB likes this.
  10. KIAB

    KIAB Well-Known Member

    Intresting mystery.
  11. The Teach

    The Teach Well-Known Member

    commonly called a potentiometer :)

    The rotary mode switch (reset) can get forced,causing the spindle to snap or bend out of position. The corresponding potentiometer can also become damaged.It may be fixable with just exchanging the mode switch knob but for peace of mind the user pcb should also be be considered. page 48.

    The new logic boiler does not use the rotary mode switch as a reset but use a push button instead ;) progress-

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