Grant vortex not switching on

[scotrock]

Hi,
Can anyone help with this problem? On boxing day my Grant Vortex combi 26 shut down it turned out to be the CH PCB which was replaced. Since that was done the boiler will not turn on with the timer I have to turn the store switch off for approx 3-4s then on and after 15s the boiler will fire up with no problem. The DHW is fine and the pressure is just above 1 bar. I did contact Grant and they thought it might be a sticking relay and said to hit the side of the boiler when it is timed on and see if it comes on I did and it didn't. Could this be a faulty PCB? or is it the relay. Thanks for your help

 

[oilboffin]

Could be a few things if it's an old boiler could be a faulty low pressure switch or a high limit switch
Would be a help to know how old the boiler is.Bob

 

[scotrock]

Hi Bob, Thanks for your reply the boiler is about 10 yrs old I have checked the low pressure switch and it is ok have not tried the high limit switch that will be my next port of call. Rod