Icos HE 24 system L9 error intermitent

[Plumb Ugly]

Got the above boiler with L9 fault appearing seemingly randomly, its happened about half a dozen times since just before xmas. The manual says its an overheat on the heat exchanger and to check the system is full, vented and that the pump is running correctly and to check the thermistors. Iv done all of the above and checked the circulation with temp clamps on the flow and return with both ch and hw on, just the ch, just the hw, ch with all trv's shut and with both zone valves closed and circulating through auto bypass. The temp differential has never exceeded 15C in any of these senarios and the fault has never occured while i have been there annoyingly. The system pressure is just above 1 bar cold and rises to just under 2 when hot, the auto air vent on the boiler is working. The house is 5 years old and the water i drained off was crystal clear. Has anyone else experienced this fault?

 

[zeebeedee]

No but I'd change the stat for good measure and check the wiring could be breaking down when hot.

 

[Plumb Ugly]

Thanks will do I don't fancy swapping the pump without exhausting everyting else first. Spoke to Ideal earlier and they suggested it may be sticking

 

[vern]

Got the above boiler with L9 fault appearing seemingly randomly, its happened about half a dozen times since just before xmas. The manual says its an overheat on the heat exchanger and to check the system is full, vented and that the pump is running correctly and to check the thermistors. Iv done all of the above and checked the circulation with temp clamps on the flow and return with both ch and hw on, just the ch, just the hw, ch with all trv's shut and with both zone valves closed and circulating through auto bypass. The temp differential has never exceeded 15C in any of these senarios and the fault has never occured while i have been there annoyingly. The system pressure is just above 1 bar cold and rises to just under 2 when hot, the auto air vent on the boiler is working. The house is 5 years old and the water i drained off was crystal clear. Has anyone else experienced this fault?

ensure the heat pads ain't fallen in the burner, common fault....can be checked via spark probe hole, if you remove 2 Allen bolts check with torch.....

Cheapest and most likely, change dry fire thermistor bout a £10 + vat, top right hand corner of hex, you will need a 13 mm deep reach socket, to make the job a doodle, make sure you fit a new fibre washer that comes with it, and also any remains of the old washer is removed, to ensure a good seal.......

next change pump head they can run slow intermittent when hot, ensure you get the right one, either wilo or myson...

 

[Plumb Ugly]

I had the burner out earlier to have a look and all good there so i think i'll order a new thermistor tomorrow and give that a whirl! its the wilo pump do you know if a standard wilo pump head will replace it?

 

[buckley plumb]

as above could be a lazy of sticking pump .

 

[jefaz]

I think every one with L9 or H9 has been a pump!! of which there are a few different types

 

[vern]

I had the burner out earlier to have a look and all good there so i think i'll order a new thermistor tomorrow and give that a whirl! its the wilo pump do you know if a standard wilo pump head will replace it?

no pal standard wilo wont fit, you need the ideal pump kit, around £100 includes bolts and o rings, becareful older ones have different width allen bolts.....

 

[AMGasServices]

Be careful when you're changing the thermistor it can cause you a pain in the back if you get air in the primary heater exchange.

As it will constantly cause it to over heat.

 

[zeebeedee]

no pal standard wilo wont fit, you need the ideal pump kit, around £100 includes bolts and o rings, becareful older ones have different width allen bolts.....

Been stung with that before!

 

[vern]

Been stung with that before!

Lol Zeb me too of course on the busiest day ever! Drilled the suckers out lol....

 

[Plumb Ugly]

If anyone is interested a new dry fire thermistor seems to have cured the problem and thanks to all who posted

 

[vern]

If anyone is interested a new dry fire thermistor seems to have cured the problem and thanks to all who posted

Send me some beer......:toilet:

 

[Plumb Ugly]

Haha your welcome to it I don't want to see another beer after last night!

 

[vern]

Haha your welcome to it I don't want to see another beer after last night!

me too....until the next time lol

 

[Plumb Ugly]

Update! Its not fixed the problem the customer called today to say it re appeared over the weekend fortunatly they are very understanding! I'm going to replace the pump head its a wilo one but the replacement iv been given is a myson when I enquired with parts centre they say they only have one pump listed for this boiler? Is this right are all replacements myson pumps now or do I need a wilo?

 

[JAH HEATING]

Update! Its not fixed the problem the customer called today to say it re appeared over the weekend fortunatly they are very understanding! I'm going to replace the pump head its a wilo one but the replacement iv been given is a myson when I enquired with parts centre they say they only have one pump listed for this boiler? Is this right are all replacements myson pumps now or do I need a wilo?

Ring ideal, there are two different pumps if I remember right.

one begins with M I think ?

 

[Plumb Ugly]

Thanks mate I will do! Its the HE series rather than the M series

 

[AMGasServices]

And there is a price difference between them. I think 1 is about £75 and the other 1 is about £125.

 

[AMGasServices]

This is what the manual states