Ideal logic combi 24

[zeebeedee]

Going to flame failure lock out only when bath is running! Checked the spark probes/rectification probes all ok. Voltage to the gas valve is fine as the resistance across the solenoid. Condensate clear and running away. 18 mb at the inlet.

Every time I go its working fine run the bath for about 10-15 minutes today and everything worked fine, heated the rads up and retried the hot water still fine. Asked the tenant when she mainly has the problem, she replied all the time which didn't help!

I am starting to think its only happening at peak times, and with her being on the fourth floor maybe the gas pressure is dropping (faulty regulator) so the inlet is way below its 18mb requirement and causing the boiler to lock out. Either that or a intermittent earth fault/pcb fault!

Thoughts anyone? This one is wrecking my head!!

 

[diamondgas]

Vertical or horizontal flue? Flue length? What, if any, fga readings you getting?

 

[zeebeedee]

Vertical flue about 2 meters, readings are fine 0.0002 and about 9.1% if memory serves me right, what you thinking there? Flue seals causing flame lift?

 

[diamondgas]

Vertical flue about 2 meters, readings are fine 0.0002 and about 9.1% if memory serves me right, what you thinking there? Flue seals causing flame lift?

Exactly

A bath potentially has the boiler running on max for a long period of time, vertical flues in general have proven more prone to a faulty seal in myexperience ...

 

[zeebeedee]

Bang goes my easy Friday, dismantle the flue it is! Fingers crossed! Cheers.

 

[diamondgas]

Bang goes my easy Friday, dismantle the flue it is! Fingers crossed! Cheers.

They're a pain to get a good fga reading on. Does the vertical flue have a sample point on them? I've not seen one on a vertical flue but it does sound like you've eliminated everything else and ignition is gas/flue end of day. They aren't just running out of gas and not lettin on are they ...lol