Worcester 24i RSF locks out

[Barnes1]

Hi All,

I've the Worcester Combi which sometimes locks out and won't fire. The vent fan will be running. If you disconnect the negative pipe off the pressure switch it will "click" , reset and the boiler will fire. It normally happens on start-up after an "off" time period of the programmer but tonight happened whilst delivering hot water.

I changed the original pressure switch with a 0.9 mb Honeywell (used but serviceable) a couple of weeks ago which ran well until tonight. The switch pipes are clear with no apparent leaks.

I have now changed the used Honeywell tonight with a brand new unit,1.0 mb but knowing my luck the problem will arise again.

Any help would be gratefully accepted.

 

[Rob]

You need to measure the contacts when it 'clicks' and doesn't fire. May also be worth checking the mutipin connector on the pcb. Could be poor contacts here.

Assuming its ok then would suspect the PCB.