noisy isar he 35

[linuxmad]

Hi all , hope someone can help , we have an Ideal isar he 35 that sounds like an elephant roaring through its trunk.
It reverberates through the house for about three or four seconds then either the boiler lights and is ok for a bit or it flashes lf on the front lcd panel.
Any clues people?

 

[weareleeds]

Call an engineer asap & don't use until he has called as a common fault on this is the flue gasket being displaced which normally makes that kind of noise also get him to check insulation panels & fit earth pin kit

 

[linuxmad]

Thanks for that.
My engineer is unable to get to me before next week but he has just said via the phone he thinks it sounds like maybe the condensate trap is blocked.
What do you think?

 

[weareleeds]

Only noise i have heard when condensate blocked is a bubbling noise within heat ex not as you described

 

[linuxmad]

Am i allowed to unblock this trap or is it contravening Corgi regs.?

 

[idealnumber1]

first of all,how old is your boiler?when is your engineer coming?

 

[linuxmad]

Hi the isar is three years old, engineer on his hols till Monday

Read up a lot on this boiler and found how to clean the condensate trap , removed it and cleaned out quite a bit of crud but no joy.

Marked the flue with marker pen to enable exact repositioning and checked for leaf debris etc, the seals are looking unblemished and intact.

According to the fault diagnosis it now looks to point at a faulty gas valve so, as i cannot replace this myself ( not corgi reg,d ) i can only assume it could be either dirt oscillating inside or a sticking sloenoid coil.

Anyone experienced this noise on one of these Isars ?

 

[idealnumber1]

the problem is you need to be able to check the gas valve to be able to say it's faulty

 

[davebgas]

Noise on an ISAR..... never!!! (coughs into hand)

A droning noise on the boiler can indicate the fan needs replacing, but also noise in operation means the burner should be checked.... have it checked for white poker dot effect as the inner plate may have deterioated or started to come loose causing incorrect burning.

LF fault code indicates ignition lockout
The overheat can give an LF fault and takes the gas valve out with it, check the overheat stat for continuity and the thermistor is fitted tight to the pipe. The gas valve should also be tested - by a corgi engineer obviously..

Hope this helps

Dave T IEng MIGEM

 

[nickso]

changing the fan to the later FIME type usually solves this. if you already have a FIME fan its usually the gas valve.

edit, just noticed this is an HE. should already have the FIME fan on.

 

[gas4you]

Working Pressure at gas meter needs checking as well.

These will make this droning noise when the gas/air mixture is too lean.

The sump may well be blocked with crud, especially on the right hand side, even though you have cleaned the trap.

 

[linuxmad]

Just to update all that responded to this problem.
The fan was the culprit, where the impeller shaft runs through a plastic rotor the hole had enlarged resulting in the shaft not making full contact.

Fixed by using an epoxy resin to seal the shaft to the rotor.
Result being a saving of £110+vat for the fan and £ ??? for labour .