Help with Hotpoint FFA81G

Hi everyone,

I'm new here and registered in the hope that someone could help me with my Hotpoint Fridge/Freeze.

The unit is a Hotpoint FFA81G, we noticed a couple of weeks ago that the lights had come on across the top, both the Freezer High Temp and the Food Defrost Alert lights. The fridge started to freeze food near the back of it, and the freezer wasn't keeping food quite frozen.

We went away at the weekend and emptied it and switched it off (last Thursday morning), we turned it on again on Sunday and it still has the lights on. I can't notice any odd sounds from it, so not to sure where to go from here.

I've found it difficult to find advice on the good old internet, although a thread i your archive here: http://www.refrigeration-engineer.co...hp/t-7446.html suggests that a replacement PCB may be the answer. However with the cost of that at £93 (from espares) it's a bit of a risk to do it, given that it may not work and a new unit would be around £300. The unit is about 6 years old.

Can anyone give me any advice on what my options are please? I'm at home today so can check anything with it immediately.

Thanks for any replies!
Chunky

Hi
It sounds like the system has lost gas , although that would be difficult to check without some guages and piercing valves, and possibly some more gas.
The PCB board would normally fail and stop the compressor running , but having some cooling I would suspect the compressor is running continuously but cannot cool correctly due to the loss of gas and the PCB is OK.
What is the refrigerant type ? you can see on the unit label or on the side of the compressor, ie it could be R134A or R600A It may be a re gas but you need a local fridgy to do it for you

Quote:

---

Originally Posted by Glenn Moore

Hi
It sounds like the system has lost gas , although that would be difficult to check without some guages and piercing valves, and possibly some more gas.
The PCB board would normally fail and stop the compressor running , but having some cooling I would suspect the compressor is running continuously but cannot cool correctly due to the loss of gas and the PCB is OK.
What is the refrigerant type ? you can see on the unit label or on the side of the compressor, ie it could be R134A or R600A It may be a re gas but you need a local fridgy to do it for you

---

Hi Glenn

Thanks for the reply. The refrigerant is R600A, according to the label in the freezer compartment.

I guess there is nothing that I can do then, I need to get someone in to look at it. My concern is that I'll spend so much on that, i might as well get a new one instead. What are the chances it'll be fixable at a relatively cheap cost?

Thanks

Hi Chunky. Any domestic repair is normally expensive but if it is short of gas then it should cost little more than a call out charge because the gas cost is minimal but the work is expensive as the gas is flammable and its elf and safty innit !!!. You can probably confirm if it is a loss of charge, if you turn the machine so you can see the back where the black serpentine coil is mounted, follow the black coil where it exits near the bottom. This tube is about 6 mm in diameter it then enters a piece of large bore tube about 22mm diam and about 100mm long, this is the drier. From the other end of this drier there is normally 2 tubes. 1 tube is a long coiled thin bore tube we call the capillary tube, the 2 nd tube is about 6mm and about 100mm long which is simply crimped flat and the end of the tube flattened. Touch this flattened end of the tube with your finger and if there is any oily residue then that is most likely where the gas has leaked from. I have repaired several for friends all with similar leaks you often see a dark mark on the metal work below this pipe on the frame where the gas and oil has dripped and dust sticks to it.. When we used the old type of gas (non flammable), this tube was brazed over after the unit was charged to make the system hermetically sealed. But since we have to use R600A (Isobutane Gas ) which is flammable this tube which is called the process stub is no longer brazed over due to it may be leaking and could ignite. So the manufacturers simply use a hydraulic crimp tool which crushes the pipe into itself to seal it and then the end is sqeezed to double seal it. It is then tested to make sure its gas tight. But over time copper tube changes with heat and age and tiny leaks can occur. After I repair and re charge these systems I always braze them over (very carefully).
One of the manufacturers of this type of unit that I used to advise on their systems design, I was discussing what they did to seal these process tubes ie crimp and flatten or crimp and braze, as my prference as always been the latter. This company do the same, but they do this process in an isolated shed for safety,. THey told me that they had one incident when brazing the process stub over, which they were lucky, when they brazed the stub the gas was leaking and a small flame the size of a small laser beam about 3 metres long ejected from the stub . It lasted about 10 seconds before the gas ran out. Luckily no one was injured, but this is why many engineers will not work on these systems in peoples houses due to insurance costs and H&S issues, and that is why you see so many cabinets especially the double door american cabinets less than a couple of years old, still in immaculate condition down the scrap yard as no one will gas them up, although if you know what your doing its easy. So it may be worth ringing around a few domestic fridge companies to see how much they would charge just for regassing. Best of luck Glenn

Hi Glen would it not be a safe practice to purge the system with nitrogoen first before doing any type of hot work on these Appliances the ones on R600a?

Hi Wilt
I tend to use a vac pump to pull a small vacuum on the system and then break the vacuum with dry air , Ill do this maybe 2 or 3 times as this pulls any residual gas out of the oil in the system , simply purging with nitrogen is no guarantee that the gas has been removed. I used this procedure on most systems if hot works are required, as if any residual gas vapour left in the system , during any un- brazing work to remove old components,this can lead to poisonous gases being emitted from the heated area similar to Phosgene gas which can kill if inhaled ,. I witnessed this many years ago on an R22 system, where the system had been pumped out and the pipe work was un brazed . |The engineer collapsed after about 10 minutes as he had been breathing the burnt R22 vapour which affected his lungs and his heart muscles. he was hospitalised for 7 days. Just something I do from from experience. Always vent safely
But you cant purge a system that has an R600A charge in it when you need to hot work the process tubes to make it hermetically sealed. KR Glenn

Glenn.
You deserve some rep points for such concise and detailed replies.
Sadly I cannot do so as I have to, as we say spread the love!
Grizzly

Hi Glenn
Thank you for your In depth reply, as you stated about the use of a vac pump I would of course go down that road & do triple vacuuming & nitro purging also can I use R134a as a drop in for R600a I would be using Line tap valves on my Fridge

Hi Wilt
No you cant just use R134A as a drop in for R600A ,for 2 reasons 1) the compressor oil would have to be changed, & 2) the capillary tube length or bore would not be compatable.
The guy I met who does this mod only does this when the original R600A compressor has failed and the replacement R134A compressor comes with the correct oil fitted, then its a case of playing with the capillary tube to change it for use with R134A ,due to the 2 refrigerants having differing mass flow characteristics.
I would stick with R600A as it will have a longer life expectancy than R134A if the clowns in the EU get their way The small domestic compressor manufacturers are only doing R&D work on their Hydrocarbon compressor range as, all the R134A, R404A etc compressor ranges will slowly be phased out as the cabinet manufacturers now virtually only manufacture Hydrocarbon cabinets.

Hi Grizz
I dont know what rep points are but thanks anyway, Just trying to pass on some of the deep technical/practical knowledge gained over the past 51 years in our great industry.Kr Glenn

Quote:

---

Originally Posted by Glenn Moore

Hi Grizz
I dont know what rep points are but thanks anyway, Just trying to pass on some of the deep technical/practical knowledge gained over the past 51 years in our great industry.Kr Glenn

---

At the bottom of each post there is a little Star and a Triangle with an exclamation mark in it.
Click on the Star to award the poster a rep point,
Which will relate to your rep power number (yours is 2 at present) I don't know how many makes up 1 rep power point but it's more than 1.
It's just a way of signifying those that contribute content that meets the approval of others on the forum.

The Triangle on the other hand is a means of registering disapproval of a particular post (reasoning given the assigned Moderator will action if he or they see fit!)
Useful when reporting spam or someone being a prat without getting into a online slanging match.

@Glenn

I advise you (and any other who work with hydrocarbon refrigerants or any other domestic refrigeration equipment), to purchase and use Vulkan Lokring tools and fittings, if you still not using them.
It is time saving and right tool for the job.

http://www.vulkan.com/en/vulkan_lokr...plications.htm



https://www.youtube.com/watch?v=zXhK...EJyPlt0Hcenq0U

Quote:

---

Originally Posted by Glenn Moore

Hi Wilt
No you cant just use R134A as a drop in for R600A ,for 2 reasons 1) the compressor oil would have to be changed, & 2) the capillary tube length or bore would not be compatable.
The guy I met who does this mod only does this when the original R600A compressor has failed and the replacement R134A compressor comes with the correct oil fitted, then its a case of playing with the capillary tube to change it for use with R134A ,due to the 2 refrigerants having differing mass flow characteristics.
I would stick with R600A as it will have a longer life expectancy than R134A if the clowns in the EU get their way The small domestic compressor manufacturers are only doing R&D work on their Hydrocarbon compressor range as, all the R134A, R404A etc compressor ranges will slowly be phased out as the cabinet manufacturers now virtually only manufacture Hydrocarbon cabinets.

---

Hi again Glenn
Thank you for pointing me in the right Direction i know about Refrigerants and Capacity,s but not on a Domestic Scale my Background is Transport Refrigeration dealing mainly with R404a & R134a for Chilled units but thoses Types of Refrigerant are soon going to be replaced & therefore Capacity,s will be altered accordingly,so thank you once again think i might skip the Fridge for what its worth been a pain since new

Hi Nike
You are probably right in todays fridge game to use Lok Ring on Domestic equipment, but old habits die hard, I served part of my apprenticeship as a coppersmith craftsman brazing and welding, and I believe a domestic should be totally hermetic, and therefore I prefer to totally braze to make it 101% leak tight , no mechanical joint is 100% tight for ever as fridge pipes expand and contract and people tread on them causeing leaks. I know of several problems recently with mechanical couplings on Co2 plants failing. Maybe that was down to poor installation procedures, but it cost a lot of money to resolve , I know of no welds or brazeing they have suffered the same problem

Hi Glen!

What I was learned is that EVERYTHING LEAKS! Even brazed joints leaks!

http://www.refrigtech.com/Product/Ma...tionManual.pdf

Therefore we can only deal with acceptable leak rate.
If leak rate is below 0,5 g/year, I am happy with any solution which can establish that, and in same time, shorten my service call time!


These are statemants of manufacturer of Vulkan-lokring:

Quote:

---

LOKRING is the preferred alternative to brazing as it is more cost effective, delivers better
quality with less failure and leak rates, as well as being faster. Furthermore, it provides an
excellent opportunity to switch tubes and components of the cycle system to cost saving
materials (e.g. aluminium).

---

Quote:

---

A correctly made LOKRING joint ensures both a zero failure rate and zero leak rate in both
plant and field. In addition, the LOKRING joint is very clean both inside and outside and there
is no possibility of damage and burns occurring from brazing inside a cabinet. Finally, it
ensures that there is no corrosion on grinded St tubes and no hazardous brazing fumes

---

https://www.youtube.com/watch?v=GAUFvx_ac2Q

http://www.vtechonline.com/pdf/vtech...%20methods.pdf

And now you can easily establish that your job is with acceptable leak rate!

http://www.refrigeration-engineer.co...p/t-43241.html

Thanks to everyone for the chat on this thread, it seems to have gone a bit off topic but appreciate the activity :)

I've not had a lot of time lately but have had a chance to look at the back of the fridge as suggested, I couldn't see any evidence of a sticky pipe or discolouring, I have taken a couple of photos to make sure I'm looking at the right thing:Attachment 11860Attachment 11861

In terms of the unit itself, it wasn't working well last week although we got by, things in the fridge door seem to be cold but if you put them at the back of the fridge then they freeze. Meanwhile the freezer compartment had all but turned into a cupboard, no cold in there at all. We went away from Sunday morning until Monday night and when we got home, the unit looked perfectly normal - lights off, all fridge cold and bread in freezer was frozen (we're not going to eat that bread, using it as an indicator!). However in the last couple of days it's reverted to it's broken state again.

Anyway, we need to get someone out to look at it, just wondered if anyone had any more comment about what could be wrong.

Thanks again for all help :)

Hi Chunky,

Bit hard to see from the pictures but is that a bit of frost at the exit of the drier?
If so need a new drier brazed in as it's getting blocked and possibly blow round circuit with nitrogen to help clear any crud out.

Drier is the bit on the right hand side, painted black with the very small pipe coming out the bottom.

Cheers,
Andy.

Thanks Andy. I'll have to have another look tonight, but I don't remember seeing any frost when i was poking around.

I guess the bottom line for me is, given the symptoms that I've explained, is my problem likely to be fixable, or is it more likely to be new fridge time?

Thanks :)