Hotpoint LTF11M132C – Error F15 stuck on constant drain

[Nick Massey]

Hi,
Hoping someone can give me some advice! I have a hotpoint LTF11M132C integrated dishwasher. Part way through the cycle, the drain pump seems to get stuck on constantly and it displays the F15 error code. Pressing the power button stops the pump and turns the machine off correctly.
Opening the machine underneath – there are no leaks and it’s completely dry.
Last week I took the drain pump out, just to check it was clean and there were no debris stuck anywhere . When I put it back together, the machine worked fine without any errors for a about 3 cycles, but now every time I run it, I get a F15 error. Any ideas?
Many thanks,
Nick

[raymassey]

Hi Nick – did you get ant response to your post – we have same error code on our appliance.
Ray Massey.

[Nick Massey]

Hi Ray, I didn’t get a response but I managed to figure it out. I found a service manual online and it said that error 15 is a ‘virtual sensor’ problem, which basically means reading between wash pump and drain pump not consistent. So one of these is either blocked or faulty.

After reading that I removed the main wash pump and found that in the chamber where the water is moved there was a load of stuff that resembled sand. I assume it was limescale as we live in a very hard water area. Cleaned it out, put it back together and it’s as good as new.

It wasn’t too difficult to do. I’ve never taken a dishwasher apart before this either. If you get stuck, give me a shout 🙂

Nick

[raymassey]

Hi Nick, thanks for your post. I have now found that we only have this code 15 error problem when we use wash programme No 1. So I am now using programme No 2 with no problems. But I fear the machine is on its way out and will need to be replaced.
Ray

[mreco99]

Hi Nick
Hows the dishwasher? still working?
Im in exactly the same situation with the same dishwasher. Ive just got it out, and am looking for the service manual that you mentioned. But i can’t find it, do you know where I can see it?
Cheers
Appreciate any help.

[electrofix]

have you got the same problem or another one ?

Dave

[mreco99]

Hi
Exactly the same problem, plus we did wash some dirty garden pots (dirt) in the dishwasher and it might well have some sandy stuff somewhere. Hence i want to do exactly what Nick did.
The dishwasher is waiting for me in the middle of the kitchen….

[electrofix]

well according to the manual

fault 15 is a drain pump problem ..

specifically The BLAC drain pump has signalled water in the dishwasher, but the dishwasher should be empty

I would find and remove the drain pump and see if there is rubbish in it

but first I would check the drain hose for blockages or kinks

Dave

[mreco99]

Thanks Dave,
When i disconnected the waste hose from the sink drainage, i found that the rubber washer between the waste hose and the waste pipe still had the circle of rubber in the rubber washer!! it was mostly cut out, except at one point, acting like a flap. So the water leaving the hose probably just about pushed it open, but i expect over time (2 years) it might have stiffened up a bit and not allowed the waste water to leave fast enough.
So I’ve removed the punched out disc from the rubber washer and put it all back together.
Now running a cycle to see if it’s ok…..

UPDATE
Can i just add something? The (electrical) plug and socket for the dishwasher is directly behind the dishwasher. There is almost no space between the back of the dishwasher and the wall, so the plug is slightly pushing on the back of the dishwasher. I know this because the back of the dishwasher has some thick black coating and i can see the impression of the plug in this black stuff. It gets pretty hot back there (i can just about keep my hand on the back of the dishwasher)
Surely this is pretty dodgy? a fire risk do you think?

[electrofix]

its meant to be a flap valve to stop water going the wrong way but they can cause problems so removing it is for the best

Dave

[mreco99]

Ok, well the dishwasher didn’t finish the cycle before all four lights were on in error. Some water was expelled as the waste pipe was warm. So ill need to check the drain pump. any hints on where it is and what it looks like?
thanks again..

In case it was missed….
Can i just add something? The (electrical) plug and socket for the dishwasher is directly behind the dishwasher. There is almost no space between the back of the dishwasher and the wall, so the plug is slightly pushing on the back of the dishwasher. I know this because the back of the dishwasher has some thick black coating and i can see the impression of the plug in this black stuff. It gets pretty hot back there (i can just about keep my hand on the back of the dishwasher)
Surely this is pretty dodgy? a fire risk do you think?

[electrofix]

unlikely to go on fire

pump has grey hose going to it. most pumps either screwed on or as turn and lock system

Dave

[mreco99]

wonderful thanks, i’ll try that tomorrow, will let you know…

[mreco99]

ok machine on back, access panel off, looks similar to your image..id upload an image but 19Kb max size is unusable small

[mreco99]

OK, got the drain pump off, it was stiff but it did twist off.
Took the waste hose completely off, checked it, not kinked and no blockage.
Because there was some waste water being expelled before the error (i know because i felt the water going down the sink waste pipe and the pipe was pretty warm) does that mean the waste pump is working ok? I don’t know if it either works or doesn’t work at this point.

I guess i need to remove the main wash pump and see if there’s any debris?

UPDATE
Now removed the main wash pump (the part with two black rubber hoses on it) . still can’t find any debris in any chamber

IF (and a big if) its the waste pump, looked it up and its £55
it’s 2.5 years old, didn’t last long eh?

Thanks for any help.

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