Isotherm fridge failure.

[Allan]

Our Isotherm type 2001 fridge has died. The fan still runs and, I think, the pump is still running. It takes about 4amps when turned on, which is pretty much what it's always taken. I think the fitting for recharging is 5/6 Acme male, so I'll need to buy the following: 1 x charging kit with gauge. 1 x can of leak stopper. 1 x can of R134a gas. 1 x 1/2 Acme to 5/6 Acme converter. I think that's about £60ish.
Has anyone done this? Is it worth the punt? Do I fill with leak stopper then let the pressure out before adding gas? Is there anything that I don't know, that I don't know? (there normally is!)
Allan

 

[vyv_cox]

Check this out first Recharging marine refrigeration systems

 

[Allan]

Check this out first Recharging marine refrigeration systems

Many thanks Vyv. I had read that sometime ago but forgot it was on your site. I've always been wary of recharging in the past as I think, if the system needs more gas, there must be a leak. I just thought that it's probably worth a try with the leak stopper. To be honest, if someone were to say "it didn't work for me", I'd probably head for Force 4 who have replacement systems for £400.
Allan

 

[superheat6k]

Add as much as you like, but if you do not find the leak and stop it (properly) you will be repeating the exercise again in short order.

R134a as a straight refrigerant can not be purchased, by non qualified persons, only R134a with the oil car AC systems use. Might be OK, but perhaps you ought to think about doing this job properly and also in compliance with the current laws.

 

[Allan]

Add as much as you like, but if you do not find the leak and stop it (properly) you will be repeating the exercise again in short order.

R134a as a straight refrigerant can not be purchased, by non qualified persons, only R134a with the oil car AC systems use. Might be OK, but perhaps you ought to think about doing this job properly and also in compliance with the current laws.

Many thanks, how do you think I can do the job properly?
Allan

 

[Daverw]

You can only do it properly if you can identify the leak repair and retest, like superheat6k I’m also a refrigeration engineer and although work on large industrial systems the principals are the same. It’s all about keeping the gas in the system. The oil in the car ac recharging cans is different and in the long term not compatible but can get it working short term. Only you can decide if a short quick fix is ok or if you cannot repair leak replace unit.

 

[Heckler]

Add as much as you like, but if you do not find the leak and stop it (properly) you will be repeating the exercise again in short order.

R134a as a straight refrigerant can not be purchased, by non qualified persons, only R134a with the oil car AC systems use. Might be OK, but perhaps you ought to think about doing this job properly and also in compliance with the current laws.

Buy refrigerant gas R134a R134 cylinders Low discount price selling

 

[Heckler]

Our Isotherm type 2001 fridge has died. The fan still runs and, I think, the pump is still running. It takes about 4amps when turned on, which is pretty much what it's always taken. I think the fitting for recharging is 5/6 Acme male, so I'll need to buy the following: 1 x charging kit with gauge. 1 x can of leak stopper. 1 x can of R134a gas. 1 x 1/2 Acme to 5/6 Acme converter. I think that's about £60ish.
Has anyone done this? Is it worth the punt? Do I fill with leak stopper then let the pressure out before adding gas? Is there anything that I don't know, that I don't know? (there normally is!)
Allan

If it has stopped working it doesnt automatically mean there is no gas in the system. You need to check that first. A set of gauges is the only way. Then if no gas, why? as others have said, where has the gas gone? Has some one done a knife defrost? or are the quick connect unions leaking. Gas is available at a price, the pros say you cant buy it, you can! Its not rocket science to refill a system, just a modicum of common sense. BUT check first for gas and if none where has it gone!

 

[Allan]

If it has stopped working it doesnt automatically mean there is no gas in the system. You need to check that first. A set of gauges is the only way. Then if no gas, why? as others have said, where has the gas gone? Has some one done a knife defrost? or are the quick connect unions leaking. Gas is available at a price, the pros say you cant buy it, you can! Its not rocket science to refill a system, just a modicum of common sense. BUT check first for gas and if none where has it gone!

Many thanks Mr Heckler. I've found gauges pipes, connectors small cans of gas and leak stopper on Amazon for about£50. There's no sign of any damage or leak but as we've both said,the gas must have gone somewhere. I was hoping to find someone who has gone through the same process.
Allan

 

[Daverw]

Please read the descriptions carefully as many of them list it as R134a but then tells you in the detail it is not R134a, also the leak stopper does not work if the leak is on the o ring connections, sometimes works for a very small pin hole on a corroded pipe as is common on a car ac.

 

[vyv_cox]

The biggest source of leaks is the push fittings between components. These are gradually being phased out, with brazed fittings being substituted. It might be worth getting someone in who can do this and regas, which should be a permanent fix.

 

[Allan]

The biggest source of leaks is the push fittings between components. These are gradually being phased out, with brazed fittings being substituted. It might be worth getting someone in who can do this and regas, which should be a permanent fix.

The compressor unit has two of the screw fittings on the out and back lines to the plate these seem to be the only connections apart from the top up valve which is soldered.
Allan

 

[superheat6k]

Buy refrigerant gas R134a R134 cylinders Low discount price selling

They might be selling it from Italy, but it is illegal to sell refrigerants to non F Gas registered firms and individuals anywhere in the EU, and UK Customs might have something to say if they discover such a consignment. It is interesting to see the Italians have just announced massively increased fines for breaking of F Gas laws and not before time. Brexit will not change our compliances in regard to the F Gas Directive.

 

[Daverw]

The compressor unit has two of the screw fittings on the out and back lines to the plate these seem to be the only connections apart from the top up valve which is soldered.
Allan

These are the most likely leak points, they are self sealing connections that allow DIY installation with the units precharged with gas, the o rings fail over time. These would never be used on a commercial installation as the pipes would just be silver soldered together.

 

[Allan]

These are the most likely leak points, they are self sealing connections that allow DIY installation with the units precharged with gas, the o rings fail over time. These would never be used on a commercial installation as the pipes would just be silver soldered together.

Many thanks for your help. Do you know if it's possible to fit new o rings? This fridge is definitely the one fitted by Bowman when the boat was built.
Allan

 

[Daverw]

Not sure if it’s possible to replace the o rings, it’s also got a sort of shut off valve built into the fitting. If you disconnected the connect you would loose all the gas and then you would have to get a vacuum pump to remove air and moisture and then recharge completely, if you were to do this you would be better cutting out the connections and silver soldering the pipes together anyway. Thats what I’ve done for a couple of friends, but I have all the gear so it’s easy, about 1 hour in total to complete. you would also have to fit an access valve to the compressor as the short pipe the factory used has most likely been crimped and soldered over, To get some one to come to you and do it locally would probably cost about £150 plus parts and gas, they would also pressure test it to make sure it’s all gas tight.
as said it’s an easy job if you’ve got the gear, to get the basic gear not too costly but you’re unlikely to need it again so more stuff in the cupboard.

 

[[70521]]

It might be cheaper, quicker just to replace the unit?

 

[Allan]

It might be cheaper, quicker just to replace the unit?

Yes sir, that's my thought. £150 + parts could be £200 to end up with a fridge that's twenty years old and repaired. £400 and a bit of work gets a new fridge. That was why I started this thread.
Allan

 

[Heckler]

Yes sir, that's my thought. £150 + parts could be £200 to end up with a fridge that's twenty years old and repaired. £400 and a bit of work gets a new fridge. That was why I started this thread.
Allan

My thoughts as well. The quick connects leaking are what I have come across in several friends boats. The O rings can be changed, however? A plus is that the new system will be a lot more efficient

 

[Heckler]

Our Isotherm type 2001 fridge has died. The fan still runs and, I think, the pump is still running. It takes about 4amps when turned on, which is pretty much what it's always taken. I think the fitting for recharging is 5/6 Acme male, so I'll need to buy the following: 1 x charging kit with gauge. 1 x can of leak stopper. 1 x can of R134a gas. 1 x 1/2 Acme to 5/6 Acme converter. I think that's about £60ish.
Has anyone done this? Is it worth the punt? Do I fill with leak stopper then let the pressure out before adding gas? Is there anything that I don't know, that I don't know? (there normally is!)
Allan

Just a thought, you have nothing to lose here. Buy a cheap can of gas plus a pipe to go to the 1/4” bsp inlet fitting that should be on your compressor or near to it. Undo the quick connects, check the O rings, if they are bad, change them, I have a box from Lidl of various sizes. Then connect the gas bottle, let a bit escape to purge the line and then let it go in with the compressor running. If it starts to cool then good. Let it run, let a bit of gas in at a time. Vyvs website gives good info on how to check the frost line as it starts to cool. If it works its a bonus and shiuldnt have cost you more than £20. If it lasts for a bit longer its a bonus, but be prepared to fit a new efficient system! Dont bother with the leak stop stuff, Ive never been impressed with it!