hotpoint mistral ff91sr (what next)

[rick]

hi im new to this forum and have been reading up on this problem for the last few days what it is since we had that spell of hot weather my fridge wont stay cool its stuck on +25 i know this topic has been covered on here a few times but i stil cant get it to work
right first i thought it was the thermister but i was told the fan in the freezer was working so it cant be so then i checked the baffle in the fridge that was open so it wasnt that
ok so then i totaly defrosted the freezer and as the temprature dropped in the freezer the cold air started to filter into the fridge i thought i had cracked it but i hadnt as the freezer temp started to get to -21 the fridge started to warm up and no air was flowing into it so i seem to be at a bit of a loss to what it is is it possibly a tempremental thermister ?because the second time i defrosted it the fridge didnt cool down at all ?and the fan didnt seem to kick in that much when the fridge was closed it just ran for a few seconds then stopped it just seems the lfow of air from freezer to fridge is somehow being restricted due to over freezing ?
is there anything else i could try ?
any help would be greatly apreciated
thanks
rick

[Dave_Conway]

Re: hotpoint mistral ff91sr (what next)

Thermistor problem I reckon if the fan is intermittent as long as you have ruled out the fridge door switch of course 😉

Dave.

[Dales-Electronic]

Re: hotpoint mistral ff91sr (what next)

OK lets try and sort this one for you. Suck eggs with me a moment. The fridge freezer works like this. From a warm start the compressor passes refrigerant into the evaporator which is located in the freezer compartment – the evaporator then cools down. There are three thermistors – two in the evaporator area and one in the fridge baffle housing. All three should show 31K at room temperature. The two in the freezer evaporator area are usually the ones you have problems with (yellow and green plugs). When the evaporator gets to -5C (and not before unless in test mode) the fan in the freezer comes on and cold air is forced around the freezer compartment and also up a tube at the left hand side of the evaporator, into the baffle housing, where (subject to the baffle flap being open) it circulates around the fridge and then is drawn down the right hand side tube back down into the freezer area. If either of these tubes is blocked with ice the fridge is too hot. If the baffle is closed the fridge is too hot. If either of the two evaporator thermistors is duff the fridge is too hot. Check these first and then if you need further help give a call. Good luck

[admin]

Re: hotpoint mistral ff91sr (what next)

ok thanks guys i just defrosted it again and took the thermisters in the freezer out then checked them and put them back in and everything seems ok for now the temp has been ok in the fridge and freezer for 24 hours now so if this happens again what thermister am i best off replacing ? any paticular one in the freezer or both ?? or the one in the fridge too ?
ok guys thanks loads for your help

[rick]

Re: hotpoint mistral ff91sr (what next)

oops that last post was me it didnt let me add my user name ?

[Dave_Conway]

Re: hotpoint mistral ff91sr (what next)

Anonymous wrote: any paticular one in the freezer or both ?? or the one in the fridge too ?
ok guys thanks loads for your help

The evaporator one is the more common one to fail, although both of the freezer one’s are prone to problems.

I can’t recall ever having to replace a fridge one though oddly enough 😕

They are here should you need either/both:

http://www.ukwhitegoods.co.uk/modules.p … Path=27_71

The top two 😉

Dave.

[rick]

Re: hotpoint mistral ff91sr (what next)

ok thanks err what page are the evaporators on just in case lol

[Dave_Conway]

Re: hotpoint mistral ff91sr (what next)

It was the evaporator thermistor I was refering too 😉

http://www.ukwhitegoods.co.uk/modules.p … cts_id=375

Dave.

[rick]

Re: hotpoint mistral ff91sr (what next)

ah right silly me
well heres the update the fridge has been running error free for 4 days or so now but ever so often the fridge temp creeps up to 18+ but i can correct it by pressing the set temp button i set it to +2 and it cools down to +2 so does this still point to the thermister ?

[Dave_Conway]

Re: hotpoint mistral ff91sr (what next)

rick wrote:so does this still point to the thermister ?

No, it points to a faulty control PCB but it could also be the fridge thermistor, rare but you never know.

Fridge thermistor is part number 2601739 at £15.17 if you want to try it, it’s not in the shop@ that one so an email to spares@ukwhitegoods.co.uk if you’d like one ordered.

Dave.

[rick]

Re: hotpoint mistral ff91sr (what next)

oh dear how much is a new pcb ???? best to try thermister first i will order one when i got some funds lol

[Dave_Conway]

Re: hotpoint mistral ff91sr (what next)

rick wrote:oh dear how much is a new pcb ????

£95.60 inclusive of VAT and delivery 🙁

Dave.

[rick]

Re: hotpoint mistral ff91sr (what next)

GULP!!! i think i will try the thermister first then
thanks for all your help and i will probably order a thermister soon

[Wilmer]

Re: hotpoint mistral ff91sr (what next)

Can someone tell me how you check whether the baffle is ok or not. My Mistral has exactly the same problem. Can the baffle get stuck closed to prevent cold air passing up into the fridge.

Also, I always find that the freezer fills up with too much ice preventing the air from circulating – why does all this ice keep forming???

This all started happening since I left the damn freezer door open 1 night. That’s all it was and now I’m to be punished for all eternity!! Domestic appliances punish me every summer without fail!!

By the way by leaving the freezer to defrost for a day the problem goes away for about 4 days then comes back again because ice has formed!
Help me someone please!!!
😥

[Dave_Conway]

Re: hotpoint mistral ff91sr (what next)

The baffle will probably be OK I think, more likely the ice build up is the problem.

Please read the many other various “mistral” threads in this forum 😀

Dave.

[Author]

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