Hotpoint fridge freezer defrosting

[Sergeant Pluck]

About to defrost this - manual here, it’s page 8.

https://www.appliancesdirect.co.uk/PDFs/NRFAA50P_UserManual1.PDF?v=1

What I can’t work out is this: does the freezer defrost independently of the fridge compartment?

Would be good if it did. Would be bad if it didn’t. There’s rather a lot of ice in there.

[PhilO]

It looks to me as if the only T control knob is in the fridge compartment, so it follows that turning it off to defrost will turn off both fridge and freezer.

But:

The fridge should stay cold for a while with the door closed. More so if full and/or equipped with cool blocks.  If it was me, I'd freeze some blocks (or plastic bottles filled with water, or similar) before starting. Then transfer those to the fridge to keep it cool while defrosting the freezer. Provided you keep the fridge door shut, you should have time to get all the ice out the freezer before the fridge starts to warm up. Use some tupperware tubs filled with hot water in the freezer drawers to speed things up.

[Feanor]

No, not really.

There is only one actual compressor wot makes the coldness. This cools the freezer down to around -18. The fridge 'piggy-backs' onto this by having a duct which takes some of the cold air from the freezer and wafting it about into the fridge. There's a fan and a motorised flappy flap on this duct to stop the freezy air circulating once the fridge gets down to around 4 degrees, or whatever has been set on the fridge dial.

The fridge will be 'frost free' by allowing the rear to warm up enough for any frost to melt and run down the drain hole, and is disposed of by ending up on an open tray on top of the warm compressor, where it will evapourate.

To defrost the freezer, you basically need to turn off the compressor for a few hours. This will allow the ice in the freezer to melt.  During this time, there will be no source of cold air for the fridge either, and it will begin to warm up. You can slow this warming by keeping the door closed, but it I'd expect it to have reached ambient room temperature by the time the freezer has fully defrosted.

Regard the defrosting process as a combined one. It will also melt any ice blocking the duct between the freezer and fridge, which can cause the freezer to get cold but the fridge to struggle to get cold.

[Wombat]

The bit about defrosting the air duct between the two is very pertinent on many Hotpoint models, and them persistently blocking up was the end failure mode in two successive Hotpoint fridge freezers for us.  Why buy another one after the first duff one (same model as caused the Grenfell fire)?  Because almost no-one else at the time sold fridge freezers with 50/50 split, they were all waaaaay too much fridge.  The replacement Hotpoint died recently, and has been replaced with a Bosch, which doesn't make 'orrible cracking noises, uses less juice, and actually keeps the fridge at the correct temperature.  Living in the sticks, we need a tall freezer, and a fridge freezer, to get an appropriate capacity.

So yes, you do need to totally defrost the whole thing, sorry!

p.s. I've gone right off Hotpoint!

[Kim]

When did they start doing this duct thing, rather than having n coils of evaporator in the fridge and n×lots coils in the freezer?

[Feanor]

Not knowing, but we recently junked a pair of John Lewis fridge-freezers for this fault.
I'm not sure what OEM brand they actually were.
In fairness, they were over 10 years old. Could have had a centerfold spot on your calendar.

The problem is that the duct is totally encased in blown foam insulation at the back of the machine.
It can become damaged with ice, and then cannot be properly fixed.

[Wombat]

When did they start doing this duct thing, rather than having n coils of evaporator in the fridge and n×lots coils in the freezer?

In Hotpoint's case, at least 18 years ago.  Our previous one had this system, and it failed several times, but we had an extended warranty, and one time they replaced the entire duct system with a new one that worked better (for a few years...).

I think our new Bosch is the same, but it does generally seem to be more reassuring in its construction, as well as not having the magic flammable plastic back panel.

[Diver300]

When did they start doing this duct thing, rather than having n coils of evaporator in the fridge and n×lots coils in the freezer?

I think that all frost-free freezers do ducts and fans and heaters to melt the frost before the user realises that that they are auto-defrost rather than frost free.

There can be problems when either the parts that shouldn't get ice in them eventually do, and conventional defrosting is needed, or some physical failure* stops the auto defrost cycle.

*One that I fixed had a welded relay contact. The relay was a DC relay that was powered from a rectifier, and de-energised too slowly, so the contacts moved apart slowly. One day the contacts welded into the cooling state, preventing the defrost cycle happening. The freezer cold parts would be blocked with ice in 1 - 2 weeks, and the cold parts weren't immediately visible and needed stuff unscrewing to defrost them in less than a day. All fixed with a new relay.

[Kim]

I think we bought our current fridge/freezer in 2005, when barkata murdered the previous one.  At the time the priorities were  a) fridge at the top  b) large freezer compartment  c) cheap  and I was wary of frost-free as a needless gimmick.  It does the split coil thing, and the only thing that's gone wrong with it was a sticky thermostat (easily replaced).  At some point the plastic parts will disintegrate, of course - they're already doing a good job of turning nicotine yellow.

[chrisbainbridge]

Interesting, we have a hot point and I would never buy another. The drainage hole never seems to drain properly and regularly I have to mop out the condensation. This is despite cleaning the pipe numerous times.

[Kim]

The drainage hole on our Beko uses that corrugated plastic pipe stuff for the drain, which seems like a particularly asking-for-it design decision in an environment where the growth of mouldy slime is pretty much inevitable.  Its drainage performance doesn't seem to have been adversely affected by routing a thin multicore cable up it to connect a temperature sensor; at least now I can give the wire a tug to encourage it to drain.

[Sergeant Pluck]

Thanks all for the info and advice.

My main concern was avoiding leaks into the flat below, which I am told happened, expensively, on a previous occasion before we lived here.

I froze some blocks of ice for the fridge as suggested, and I used a fan which appeared to speed things up dramatically. The only duct I can see between the two compartments is what looks like a small drain at the back of the fridge compartment. I ran a couple of pipe cleaners through it as far as I was able and it seems to be clear to that extent anyway.

All done in about 5 hours, most freezer food survived in an insulated bag.

[arabella]

Chortle.
I realise I don't have a fridge freezer, it's a fridge with and ice box jobby, originally purchased 1989 or thenabouts.
It takes somewhat longer than 5 hours to defrost, but then I don't do it very frequently

TLDR: <nothing to say>

[Feanor]

My main concern was avoiding leaks into the flat below, which I am told happened, expensively, on a previous occasion before we lived here.

The quantity of water generated by defrosting a fridge-freezer is not even in the same order of magnitude of the quantity to flood the downstairs flat, under normal circumstances!

We're talking 'spilling a bowl of water in the kitchen', not 'having a 22mm pipe running at full-bore for 24 hours'.

[Sergeant Pluck]

The quantity of water was enough to require a new kitchen ceiling for the flat below prior to our tenancy. And at the start of our tenancy, a small bathroom pipe leak was enough to lead to a new bathroom ceiling for them too. And this is is in a purpose-built block.