Not sure where to post this so here goes. I have a 3way fridge in an RV.
If my fridge can operate at 0/c degrees at 15c degrees ambient what would prevent my fridge from maintaining that temp when the ambient temperature rises? *************************************************** 09-11-06, 12:42 PM Walks On Water Welcome to our site. I am sure you will find a lot of answers here.
Now, on to your question. This question I am qualified to answer for two reasons, one it is my trade and the other, I also have a RV.
These units do not have a motor as in a conventional refrigerator. They use the old stand by know as “Absorption.”
Most here in the US would know this as a Servel Refrigertor which is just one brand name.
This is powered by a heater that boils a solution of ammonia. In your system, there are 3 sources of heat. Gas flame from propane, 120 or 240 electric and 12 volts DC from the RV’s system. 3 Way.
Now before I can start to determine your problem, I have a few questions.
1) Is this RV stationary or do you drive it from camp ground to camp ground. Here in the states, we have those who just leave their RV’s parked for the summer and use it like a cottage.
2) Which do use while parked? 120-240 volts. Propane or LP gas. And I think 12 volts is out as it would only used while traveling as it would use a lot of battery power.
3) If you use propane, have you tried it on 120-240 volts? I have been saying 120-240 volts as I don’t know what the standard is down under.
4) When was the last time you clean your condenser coil and checked for “nests”?
5) How old is it.
6) How often do you use it? By use it, do you leave it on all the time. Only a couple of time a month.
7) Which of the 3 power sources do you use the most?
09-11-06, 02:36 PM masaloi Thank you for taking time out to present me with detailed questions. This fridge does work but "seems" not to maintain an acceptable cold temp under hot conditions and I do have a fan installed in the fridge for better circulation as well as another fan to exhaust the heat through the flu.
Now before I can start to determine your problem, I have a few questions.
1) Is this RV stationary or do you drive it from camp ground to camp ground. Here in the states, we have those who just leave their RV’s parked for the summer and use it like a cottage.MOBILE
2) Which do use while parked? 120-240 volts. Propane or LP gas. And I think this one is out as it would only used while traveling as it would use a lot of battery power.LPG
3) If you use propane, have you tried it on 120-240 volts? I have been saying 120-240 volts as I don’t know what the standard is down under.YES...240v.
4) When was the last time you clean your condenser coil and checked for “nests”?It is CLEAN
5) How old is it.???Installed NEW in 2001
6) How often do you use it? By use it, do you leave it on all the time. Only a couple of time a month.Often stand for months at a time.
7) Which of the 3 power sources do you use the most?LPG
09-11-06, 07:23 PM Walks On Water Couple of last questions, does to perform better on electricity or LPG over a 48 hour period. Or is about the same? This will tell me if the problem is on the LPG end.
Did it work OK when you first got it?
15 deg C is about 60 deg F. This should not be a factor.
Mine works well even as warm a 90s F.
09-11-06, 10:06 PM masaloi with regard to your first question I have not carried out a comparitive test over a 48hour period but would guess it would favour 240v.
Yes it did work Ok in 2003 when I purchased the RV.
I have taken the fridge out and tumbled it in case there were any tube blocks.
This morning I put the fridge which is empty on 12v.and have just now 1pm taken a reading. Ambient 23.2c fridge 4.8c The fridge thermostat is on 7.
Whilst this fridge temp is acceptable at the above ambient temp, my concern is as initially stated the fridge is unable to maintain this temp when the ambient is 27c and above....wondering what could be the reason as this fridge is graded as a TROPICAL fridge therefore it should be able to cope with the higher temps.
09-12-06, 07:55 AM Walks On Water As I said before in this column, it is hard to diagnose Air Conditioning or Refrigerator problems without “Laying Hands” on it but I will educate so that you will have an idea what may be your problem.
Let’s start here, if the unit works on 240 volts and 12 vdc your problem is with the LPG. I would not really on 12 volts for the test as this is not the best source of heat. May keep a frige at temperature once pulled down but I don't think it is reliable.
The first item I check is gas pressure. On my unit there is a gas test port on the front. This is read using a “Water Tube Manometer” in inches water column. You would need to check you refrigerator’s manual for the proper setting. I don’t believe this is your problem as this seldom changes once set by the factory.
Next I check the flame size. For those that read this, if you have a LPG refrigerator the next time you are using it check your flame at full cool so you have a base for comparison. The smaller the flame the less it will cool. As your refrigerator reaches set point, the thermostat reduces the flame size lowering its ability to cool. If you can’t get full flame, you can’t get full cool.
What happens in my unit is the fuel supply line gets plugged with rust. When your unit is off, the fuel in this line is replaced with humid air. This moisture attacks this steel tube and rust dust forms blocking this tube over a period of time.
Now, this is an easy problem to correct if you have mechanical ability. You must, CAREFULLY disassemble the burner unit. Remove the burner head. Mine screws on. Either in the head or in the burner base you will find a burner orifice. If you look in it, you will see the pin hole orifice. This is a precision hole so don’t use a pin to clean it. If you can see light through it, it should be OK.
Now check the gas feed tube. See if you can blow through it. If you see what appears to be a build up of a fine dust, clean it our. This may be packed it there so you may have to dig a little. I have to clean mine every 3 or 4 years.
Reassemble everything and be sure you have no leaks. Use a little soap water and brush all joints and watch for bubbles.
While you are checking, there is, on most units, a chain or rod that drops down the flue pipe. This chain keeps soot from building up on the boiler surfaces by swing around, knocking it off during travel. Sometimes you have to take a brush and give it a little help.
Now, if you find that it does not work on any source, and you checked you condenser and it is clean, then you may have a “Vapor Lock” in the tubes somewhere. Masaloi has already guessed that. By taking the unit out and rolling it on all sides will dislodge any vapor locks. I told a fellow camper about this and he laugh until he tried it. He did not laugh at my suggestion after he tried it and the frige started work again.
Vapor locks and a sooty flue are the major problems in units that are not moved on a regular bases. While rust in the fuel tube is the major problem with units that spend a lot of time off.
If, at anytime, you smell ammonia, you may have a leak somewhere and these units are hard to repair and recharge.
I know this is long but it is the only way I can help.
09-12-06, 02:43 PM masaloi As I said before in this column, it is hard to diagnose Air Conditioning or Refrigerator problems without “Laying Hands” on it but I will educate so that you will have an idea what may be your problem.
Let’s start here, if the unit works on 240 volts and 12 vdc your problem is with the LPG. I would not really on 12 volts for the test as this is not the best source of heat. May keep a frige at temperature once pulled down but I don't think it is reliable.
The first item I check is gas pressure. On my unit there is a gas test port on the front. This is read using a “Water Tube Manometer” in inches water column. You would need to check you refrigerator’s manual for the proper setting. I don’t believe this is your problem as this seldom changes once set by the factory Unless one has the proper measuring equipment then this is one for the specialist I believe. Next I check the flame size. For those that read this, if you have a LPG refrigerator the next time you are using it check your flame at full cool so you have a base for comparison. The smaller the flame the less it will cool. As your refrigerator reaches set point, the thermostat reduces the flame size lowering its ability to cool. If you can’t get full flame, you can’t get full cool.Appreciate this point but what is "full" flame to the novice as I do have what I understand to be correct flame but it is not "fierce" as such but is a full blue flame. What happens in my unit is the fuel supply line gets plugged with rust. When your unit is off, the fuel in this line is replaced with humid air. This moisture attacks this steel tube and rust dust forms blocking this tube over a period of time.
Now, this is an easy problem to correct if you have mechanical ability. You must, CAREFULLY disassemble the burner unit. Remove the burner head. Mine screws on. Either in the head or in the burner base you will find a burner orifice. If you look in it, you will see the pin hole orifice. This is a precision hole so don’t use a pin to clean it. If you can see light through it, it should be OK. I have carried out this procedure. Now check the gas feed tube. See if you can blow through it. If you see what appears to be a build up of a fine dust, clean it our. This may be packed it there so you may have to dig a little. I have to clean mine every 3 or 4 years. Is this the tube that runs right back to the gas bottle regulator Reassemble everything and be sure you have no leaks. Use a little soap water and brush all joints and watch for bubbles.
While you are checking, there is, on most units, a chain or rod that drops down the flue pipe. This chain keeps soot from building up on the boiler surfaces by swing around, knocking it off during travel. Sometimes you have to take a brush and give it a little help.Flue clean Now, if you find that it does not work on any source, and you checked you condenser and it is clean, then you may have a “Vapor Lock” in the tubes somewhere. Masaloi has already guessed that. By taking the unit out and rolling it on all sides will dislodge any vapor locks. I told a fellow camper about this and he laugh until he tried it. He did not laugh at my suggestion after he tried it and the frige started work again.
Vapor locks and a sooty flue are the major problems in units that are not moved on a regular bases. While rust in the fuel tube is the major problem with units that spend a lot of time off.
If, at anytime, you smell ammonia, you may have a leak somewhere and these units are hard to repair and recharge.
I know this is long but it is the only way I can help. With regards to LPG other than cleaning out the gas feed tube could the regulator have any bearing on perhaps loss of gas pressure? Thanks for your untiring efforts you have made the case quite clear and given a number of points for each of us to consider that view this post.
09-15-06, 07:15 AM masaloi I have blown out the gas line, no obvious problem there. I reset the MT fridge to 12volt and it got down to -5.4C at ambient of 18.4C and -3.7C at 24.2C it just seems to be on the gas that it won't perform well 24.5/6.9 and 23.2/8 and 18.2/6.5
Realise that you have helped as much as you can from a distance and appreciate that very much.
I did clean the 12v terminal contact as it was rusty so perhaps that has fed a bit more current to it???.
Just thought you'd appreciate the feedback which could also have some benefit to others.
09-21-06, 01:31 PM masaloi As the frige continued to behave with inconsistentcy with regards to temperatures I finally had to take the fridge to the only recognised expert here on the coast. regrettably it was one of those "not normal" behaviour patterns which even created a bit of a challenge to him. Apparently it did finish up as an irregular thermo problem that affected the gas flow more than it affected the ac/dc heating. Seems that over a period the thermo and regulator collected an overdose of "oil"! would that be correct. On and off between other jobs he was doing and the daily temp testings he had the RV for 4 days. Pretty expensive buggers these fridges.....all up it cost me $358...$200 for his time and the rest for a new thermo and regulator. I don't question his integrity or expertise as from time to time you do get these exceptional tricky ones and he did start by keeping it simple like checking the jet then working his way through the more complex possibilities. Hopefully it will be OK as I am not free to pick it up for a few days and give it a good test myself. Anyway your help and this experience has given me much more confidence in an area I have never ventured before. Would appreciate any feedback you might have.
09-22-06, 11:02 AM Walks On Water It only figured that if it worker OK on electric, it had to somewhere in the gas circuit.
I will have to remember that one in the future. I would wonder how oil would get in the theromstat?
09-22-06, 12:18 PM masaloi Yeh, not sure on that one myself that is why I !!! questioned that in my email to you.....from my imaginations..the thermo is a sealed unit. When I eventually pick it up on Monday I'll do a heavy enquiry if I can catch the guy.
This message has been edited. Last edited by: DorianGreyed,
Posts: 7 | Location: australia | Registered: 09-11-06
