Glow Worm Cx381 = F14 fault

[cycling_blue]

Hi, I have a GlowWorm Cx381 condensing boiler and I am getting a F14 fault (the hot water heats up but after a couple of minutes the F14 fault appears, water goes cold, then water heats up again). The British Gas engineer said this was caused by the heat plate being blocked and recommended a power flush of the CH system (as well as replacing the heat plate) as he thought the gunk from the CH system had blocked the plate. I am confused as to why the CH causes an issue with the HW - I appreciate they both pass through the plate but surely they are separate systems? BG have quoted £790 for power flush with seems exorbitant especially if it is not the root cause. Any ideas? Thanks

 

[Stadan20]

Wow that's a lot , get the hw plate replaced by a local gas guy and go from there , it may pay to get a system filter fitted on your system also

 

[SandyLyon]

It's the same water that circulates through your radiators that is diverted through the plate heat exchanger where the heat "exchanges" (transfers) to the mains cold water that also passes through the plate heat exchanger to produce hot water at the tap.
The two are totally separate and the plate heat exchanger is just a device that allows the hot central heating water to heat the MCW to produce HW just as a indirect cylinder does.
The very small waterways can become gunged up on the CH side with scale / crap hence the power flush / inhibitor / filter recommendations.
Just replacing the Plate Heat Exchanger will sort it in the short term but unless the system is flushed with a cleanser an inhibitor added and a good quality filter fitted on the return pipe close to the boiler, it will get blocked again.

 

[Gas2Air]

Hi, I have a GlowWorm Cx381 condensing boiler and I am getting a F14 fault (the hot water heats up but after a couple of minutes the F14 fault appears, water goes cold, then water heats up again). The British Gas engineer said this was caused by the heat plate being blocked and recommended a power flush of the CH system (as well as replacing the heat plate) as he thought the gunk from the CH system had blocked the plate. I am confused as to why the CH causes an issue with the HW - I appreciate they both pass through the plate but surely they are separate systems? BG have quoted £790 for power flush with seems exorbitant especially if it is not the root cause. Any ideas? Thanks

"exorbitant" Another one that forgets about their boiler until something happens. Then expect it to be fixed for minimal amount or for free. Take your car in after it's not had oil in it for years and see what they say. "exorbitant" you'd probably say. The engineer has diagnosed correctly and has recommended a powerflush, what is your point?

 

[cycling_blue]

It's the same water that circulates through your radiators that is diverted through the plate heat exchanger where the heat "exchanges" (transfers) to the mains cold water that also passes through the plate heat exchanger to produce hot water at the tap.
The two are totally separate and the plate heat exchanger is just a device that allows the hot central heating water to heat the MCW to produce HW just as a indirect cylinder does.
The very small waterways can become gunged up on the CH side with scale / crap hence the power flush / inhibitor / filter recommendations.
Just replacing the Plate Heat Exchanger will sort it in the short term but unless the system is flushed with a cleanser an inhibitor added and a good quality filter fitted on the return pipe close to the boiler, it will get blocked again.

Thanks, that explains it very nicely.

 

[cycling_blue]

Hi, I have a GlowWorm Cx381 condensing boiler and I am getting a F14 fault (the hot water heats up but after a couple of minutes the F14 fault appears, water goes cold, then water heats up again). The British Gas engineer said this was caused by the heat plate being blocked and recommended a power flush of the CH system (as well as replacing the heat plate) as he thought the gunk from the CH system had blocked the plate. I am confused as to why the CH causes an issue with the HW - I appreciate they both pass through the plate but surely they are separate systems? BG have quoted £790 for power flush with seems exorbitant especially if it is not the root cause. Any ideas? Thanks

"exorbitant" Another one that forgets about their boiler until something happens. Then expect it to be fixed for minimal amount or for free. Take your car in after it's not had oil in it for years and see what they say. "exorbitant" you'd probably say. The engineer has diagnosed correctly and has recommended a powerflush, what is your point?

Actually, my boiler has been under BG contract for many years, serviced annually.