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Frisbeekev
07-26-2020, 07:11 AM
We are out on a 2 week trip and having to run the AC. We e run it between 65 and 70 and it runs great all day, then at. Night or shuts off but never cycles back on even as the temp in the trailer rises. Does anyone know what the issue may be? Is it a temastat issue or the AC unit itself? Also how often should the freon in the AC unit be replaced and is it something easy to do?

flybouy
07-26-2020, 07:20 AM
Sounds like a thermostat issue. What type of t'stat do you have? The refrigerant in the a/c unit is not serviceable and there is no need to "replace" it.

chuckster57
07-26-2020, 07:58 AM
Sounds like a thermostat issue. What type of t'stat do you have? The refrigerant in the a/c unit is not serviceable and there is no need to "replace" it.

I agree, must likely a tstat issue. If you turn it to off and then back to cool, does it start working again?

JRTJH
07-26-2020, 08:31 AM
A couple of things come to mind, but first, all RV air conditioners used in Keystone products are "sealed units" and the freon is not "replaceable".

I don't believe your Passport 2920BH has an option for 50 amp power, so it's a 30 amp unit ??? If that's true, then the biggest available A/C unit is a 15K rooftop model. A single A/C on a 32' trailer will have SIGNIFICANT DIFFICULTY in keeping that volume of interior space cool in hotter weather. Most people complain that their 32' trailer can barely keep the interior cooler than around 80F or so on hot days or when parked in direct sunlight.

So, if you're consistently cooling your unit to 65-70F during the day, thank your "lucky stars" that your trailer is performing so well... Most aren't even close to the ability to cool their trailer to those low temps...

That said, if you're leaving the thermostat at that temperature setting during the cooler evenings, you may be experiencing "coil freezeup" rather than thermostat problems. As the warmer, moist air passes through the evaporator coils, the moisture condenses on the fins. If the fins are extremely cold, sometimes that moisture freezes in the passageways and the ice blocks air movement, causing the air conditioner to stop moving air across the coils.

There is a freeze detector installed in the coils. It detects the cold temperatures and if they drop too low, they call for the compressor to shut down for a bit. This keeps the coils from freezing and prevents the ice blockages. Your freeze detector may have vibrated out of the evaporator coils or it may be positioned too low in the coils, allowing the upper part of the coils to get too cold.

I'd suggest you check the location and proper positioning of the freeze detector in your air conditioner. You can access it through the filter opening on many models, or you may need to remove the inside overhead part of the air conditioner to access it on some models....

Another consideration would be the fan speed. Many people turn the A/C fan to LOW speed at night to reduce the noise. That also reduces the air flow over the coils and increases the potential for coil freeze up or partial freeze up. If you keep your thermostat set on a "low temperature", say around 60F or so, you may be "causing the problem" with the thermostat on that setting and the fan speed on LOW.

However, if you can attain interior temperatures in a 32' RV of 65F on a warm day, you've got a remarkably well functioning A/C, so I doubt it's a "BTU capacity issue" in not being able to maintain those temps when it's cooler. Rather, I'd suspect it's a performance issue. First would be the freeze detector placement and second would be a good cleaning of the air filter and keeping the fan either on HIGH speed or in AUTO.

flybouy
07-26-2020, 08:52 AM
John brings up a good point. I forgot where you are from and if you are camping anywhere in the mid-Atlantic area the last few weeks have been brutal. Temps in the upper 90's with very high dew points (humidity).

In our 35' camper we have 30 amp service and a 15K a/c. On extremely hot days I'll cover the windows with dark towels to block the radiant heat and with the bathroom exterior door I'll make everyone exit/enter thru that door. It acts like a vestibule in buffering the outside to to inside air. The outside kitchen also helps prevent the constant in and out of the camper by placing drinks, the next meal's meats & veggies and condiments outside. The outside kitchen in ours is large with ample cabinets that hold all the plates, etc. we need. A Thule portable shelf under the awning above the outside 120 outlet is where we keep the ice maker as well.

By doing these things we've never had inside temps over 76 on the hottest of days but it takes diligence in keeping that front door closed. Not easy to do with little ones I know. We keep the a/c fan on high at all times.

Frisbeekev
07-26-2020, 06:16 PM
Sounds like a thermostat issue. What type of t'stat do you have? The refrigerant in the a/c unit is not serviceable and there is no need to "replace" it.

Good to know about the refirgerant. The thermostat is the standard domestic that comes with the unit.

Frisbeekev
07-26-2020, 06:17 PM
I agree, must likely a tstat issue. If you turn it to off and then back to cool, does it start working again?

Yeah I have to get up at night and turn it off then back on and it works again.

Frisbeekev
07-26-2020, 06:21 PM
A couple of things come to mind, but first, all RV air conditioners used in Keystone products are "sealed units" and the freon is not "replaceable".

I don't believe your Passport 2920BH has an option for 50 amp power, so it's a 30 amp unit ??? If that's true, then the biggest available A/C unit is a 15K rooftop model. A single A/C on a 32' trailer will have SIGNIFICANT DIFFICULTY in keeping that volume of interior space cool in hotter weather. Most people complain that their 32' trailer can barely keep the interior cooler than around 80F or so on hot days or when parked in direct sunlight.

So, if you're consistently cooling your unit to 65-70F during the day, thank your "lucky stars" that your trailer is performing so well... Most aren't even close to the ability to cool their trailer to those low temps...

That said, if you're leaving the thermostat at that temperature setting during the cooler evenings, you may be experiencing "coil freezeup" rather than thermostat problems. As the warmer, moist air passes through the evaporator coils, the moisture condenses on the fins. If the fins are extremely cold, sometimes that moisture freezes in the passageways and the ice blocks air movement, causing the air conditioner to stop moving air across the coils.

There is a freeze detector installed in the coils. It detects the cold temperatures and if they drop too low, they call for the compressor to shut down for a bit. This keeps the coils from freezing and prevents the ice blockages. Your freeze detector may have vibrated out of the evaporator coils or it may be positioned too low in the coils, allowing the upper part of the coils to get too cold.

I'd suggest you check the location and proper positioning of the freeze detector in your air conditioner. You can access it through the filter opening on many models, or you may need to remove the inside overhead part of the air conditioner to access it on some models....

Another consideration would be the fan speed. Many people turn the A/C fan to LOW speed at night to reduce the noise. That also reduces the air flow over the coils and increases the potential for coil freeze up or partial freeze up. If you keep your thermostat set on a "low temperature", say around 60F or so, you may be "causing the problem" with the thermostat on that setting and the fan speed on LOW.

However, if you can attain interior temperatures in a 32' RV of 65F on a warm day, you've got a remarkably well functioning A/C, so I doubt it's a "BTU capacity issue" in not being able to maintain those temps when it's cooler. Rather, I'd suspect it's a performance issue. First would be the freeze detector placement and second would be a good cleaning of the air filter and keeping the fan either on HIGH speed or in AUTO.

It is 30amp unit. I will check the freeze detector. I took the filter off the other day to clean it and ice came out from the unit so it may be a freeze issue.
I will also run on high fan or auto and see if that makes a difference. We are in Tennessee and Kentucky and it has been hot so it has had to work extra hard

Frisbeekev
07-26-2020, 06:22 PM
Thanks for all the input I will try these things. We are from MD bit in Tennessee and Kentucky and it has been hot so it has had to work pretty hard.

flybouy
07-26-2020, 06:35 PM
It is 30amp unit. I will check the freeze detector. I took the filter off the other day to clean it and ice came out from the unit so it may be a freeze issue.
I will also run on high fan or auto and see if that makes a difference. We are in Tennessee and Kentucky and it has been hot so it has had to work extra hard

I think you just identified your issue. There should not be any ice in the unit. How dirty was the filter? If it was clogged up it can cause the icing condition by severely restricting the airflow. I've been in some cg's where windy conditions or dusty busy roads required a daily washing of the filter.