Worcester 24i RSF won't stay lit

[blippy]

Hi,

I have an LPG 24i which has recently developed a fault on both DHW and CH.

When there's demand, the boiler goes through the ignition sequence correctly, there's a good spark and ignition occurs. Sparking stops once the flame reaches the ignition sensor. However, after about 3-4 seconds one of the relays on the PCB drops out (sometimes it bounces for 1/2 a second), and then the gas valve is turned off (relay 4 drops out). Then the whole ignition sequence repeats, and fails etc. etc.

The boiler was professionally serviced last October, burner pressures adjusted and the burner properly cleaned etc.

I checked everything I can from similar threads here - specifically reversed polarity and ignition sensor condition/connection, but nothing obvious is out of place.

Grateful for any further pointers.

Cheers,
Chris

 

[keego]

Have you checked the flame rectification probe?

 

[blippy]

What's one of those if not the ignition sensor?

 

[ChrisR]

You've gone as far as you safely can. LPG can be particularly nasty. Call your corgi man back. May be all sorts, including the PCB.

 

[blippy]

Thanks Chris, I'll get someone in on Monday.