F3 Heat Exchanger Blocked

[Deanooo]

Hi guys,

Hope someone on here can help me alittle?
I am getting a fault code of F3 (heat exchanger blocked) on my Jaguar Combi boiler, this comes after the boiler kicks in for DHW or CH
I then reset the system with the reset button on the front panel and I then have the error F1 (NO Flame or Overheating of the Boiler) the only way to get a flame is to reset the overheat thermastat inside the casing.

Would this indicate that I have a some form of overheating in relation to the Heat exchanger??

Sorry my knowledge on boilers is very limited I think I know more now since looking and reading the manual than I ever have about boilers.

Just 1 note to add is that its about 7 years old and I know in the last 6 years its never been serviced

 

[ChrisR]

Well it makes sense: no circulation because the hex is blocked so it overheats and goes out. Maybe could be a dud pump.
Strightforward boiler which should be mendable.

 

[Deanooo]

Thanks for that.

That could make sense as when it cuts out there is an awful clunking noise coming from around the pump area and the sound as if something is falling within the guts of the Boiler.

Sods Law I have the in-laws coming this weekend couldn't of happened at a better time!!

 

[twgas]

have you checked the pressure

 

[nickso]

if its not the pressure i would go for the pump unless you have particularly poor water quality in the system.

check the pump connections/wiring, ive had three of these with dodgy connections at the plug that goes into the pump. they were arcing across terminals and only switching the pump on intermittantly.

 

[Agile]

It will not be the pressure as that would give the LP fault code.

It certainly sounds as if the pump is blocked or failed or the HE badly blocked but thats unlikely as its only the main HE involved as its both DHW and CH so investigate the pump!

Tony