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Heat pump issues


michaelivan
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I am having issues with one of my original Dometic Penguin heat pumps on my 2003 Monaco.  There are currently  2 original 13.5 Penguin heat pumps working off of the standard 5 button thermostat. It is the front unit that is used the most to keep the unit comfortable. It is starting to misbehave in the following manner:  The unit will come on, start to cool with the air reaching about the 57-58 degree range as measured at the ceiling vent.  After about 5 minutes, the compressor kicks off, the fan kicks into high speed and runs for about 2-3 minutes.  The unit then shuts off.  The unit will continue to act this way until it slowly has cooled the area to the desired temperature then stops cycling until the temperature rises and calls for the unit to restart again.  I have replaced the thermostat and the control board in the unit, pulled the cover and cleaned all of the cooling fins, but still have the same issue. 

My first thought would be to put a bullet piercing tap into the low pressure side and recharge the system.  Is such a fix feasible?  If not then the next option would be to replace the front unit.  From there the option would be to replace both units since the rear unit is of the same age (17 years) and install the new 10 button thermostat.  If I decide to go that route, what would I need other than the two units and the thermostat? 

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Hi Mike ,  Your symptoms are just what I have when air is directed to much toward the thermostat sensor .                                                                            

If you decide to replace both units you will need the new 10 button thermostat and 2 drain pan kits .

The rest is plug & play , hardest part is getting them on the roof .

https://www.ebay.com/itm/Dometic-3107688-016-Auxiliary-Drain-Pan-Kit/223844909809?epid=1023679643&hash=item341e3242f1:g:LsgAAOSwhJteGJ3i

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I have disconnected the remote sensor, made sure that airflow is not directed at the thermostat (even close the door) but nothing changes. Sometimes the unit will cool the air to about 50 degrees depending on ambient temperature. 

The units that I have now have drain kits installed so will they work with the new units?

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11 minutes ago, michaelivan said:

I have disconnected the remote sensor, made sure that airflow is not directed at the thermostat (even close the door) but nothing changes. Sometimes the unit will cool the air to about 50 degrees depending on ambient temperature. 

The units that I have now have drain kits installed so will they work with the new units?

Yes the old drains will work but they are plastic and you know what age does to most plastic .   I thought about trying to reuse mine but decided against it so I ordered new ones and had them on hand before starting .  Of course the drain kits were only about 50 bucks then .  Now I might try using the old ones .

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The old drains can be adapted but you will need to drill new holes in the bottom steel pan.  You will also need two A/C to roof gaskets each to make space for the drains. 

If you decide to replace only one of the front heat pumps then you will need a retrofit control board for it to work with your old 5 button CCC thermostat and the older heat pump.  You cannot adapt an older heat pump or A/C to the new 10 button thermostat. 

They are saying it's very difficult to locate new A/C or heat pumps after Covid-19.  I'd check with PPL Motor Home parts.  

Edited by vito.a
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Your symptoms are similar to what they call "short cycling". I had that with my front old Penguin that was driving me crazy until the start capacitor took a dump Replaced it without any change to the short cycling and eventually the new start capacitor blew again. I left it that way and just used the rear AC as it was getting towards fall weather anyway. Well a few weeks later my rear AC decided to quit completely so we were without ANY AC at all. Once I got to our Florida winter residence I ordered two new Penguin II's, a new 10 button CCC-2 and two new drain kits. This was back in 2018.

Absolutely love the new Penguin II's and the CCC-2 is 1000 times better than the old 5 button CCC. The inside of the Penguin is heavily insulated and sealed where needed, unlike the old Penguin's. Well worth the changeover!

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I recently bought one at Adventure RV as did Walter McNeil who is also on this forum .

PPL didn't have any at that time which was July 24th for me  .

I thought the Dometic Penguins were probably from China but mine was from Mexico which may help with availability issues .

Vito is correct , you will need 2 gaskets per A/C . Rather than me trying to explain it when you flip the old A/C up side down

you will plainly see how to cut and install the drains and gaskets .

Walter's new A/C came with a gasket installed on his A/C mine did not , go figure .  Gaskets are available at any RV place so if you have a place

nearby you might wait and see if your new unit has a gasket with it , either way you will need 2 gaskets .

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13 hours ago, michaelivan said:

I am having issues with one of my original Dometic Penguin heat pumps on my 2003 Monaco....It is starting to misbehave in the following manner:  The unit will come on, start to cool with the air reaching about the 57-58 degree range as measured at the ceiling vent.  After about 5 minutes, the compressor kicks off, the fan kicks into high speed and runs for about 2-3 minutes.  The unit then shuts off.  

Can you see up into the evaporator? That sounds to me like what the AC would do if the evaporator was frozen up.

If it’s not freezing up, maybe something wrong with the freeze sensor? In that case maybe swap the freeze sensor with one of the other units. 
Cheers

Walter

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4 hours ago, wamcneil said:

Can you see up into the evaporator? That sounds to me like what the AC would do if the evaporator was frozen up.

If it’s not freezing up, maybe something wrong with the freeze sensor? In that case maybe swap the freeze sensor with one of the other units. 
Cheers

Walter

Agree, sounds like it cycling off due to the evaporator frost sensor. When's the last time you cleaned the return filters?

Could be a dirty evap (probably most likely) or low charge (probably less likely); least likely of all could be the evap frost sensor is bad. Try running it with the fan manually on hi. If it runs longer, I'd suspect a dirty evap.

Edited by trailmug
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Mike   Mine started acting up similar to yours I found the coupler connecting the data wire from the thermostat to the unit had corroded inside. Probably causing the unit to keep getting mixed signals. I cleaned the jack ends and got new couplers and it behaves like normal now.

Roy      

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If you have a thermocouple, maybe jam it in there. The room temp thermistor is a run-of-the-mill 6.8 kOhm unit, and the freeze sensor is probably the same. I've also read reports of the polystyrene foam in the supply ducts coming off/apart and blocking airflow. Ours spits some out every now and then so I assume I'll have to deal with that someday.

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Swapped out the sensors and nothing changed.  My thought now is to go ahead and bite the bullet and replace.  Since no one has the Penguin models in stock I am considering using the Brisk Air heat pumps instead.  I realize that they are a little taller but they would still be lower than my satellite tv dome.  Has anyone tried that conversion and if so is it still a basic bolt one, plug and play conversion?

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Seems to me that one other member did the same switch and the plug and play was fine EXCEPT for securing the AC to the ceiling bracket. I believe the bolt pattern is not the same.

Actually, if I remember correctly the switch was for the Dometic Blizzard, not the Dometic Brisk Air but I really can't remember exactly. You could call Dometic Technical Service to see what they would say.

You can do a search for that post and I will look around too. If I find it I will edit this post with the link.

Edited by Dr4Film
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4 hours ago, michaelivan said:

Swapped out the sensors and nothing changed.  

One last easy thing to try... swap circuit boards between two units? 
If that’s the problem I can supply another good board. 
I just replaced a rooftop unit. Its not as glamorous as it sounds.
It’s a lot of trouble and expense, and then you wind up with a shiny new AC that performs just a little bit better than the old one.  
Cheers

Walter

4 hours ago, Dr4Film said:

Seems to me that one other member did the same switch and the plug and play was fine EXCEPT for securing the AC to the ceiling bracket. I believe the bolt pattern is not the same.

Yeah, that was my take-away from his story. I think that was buried in the thread about Penguin II availability?

The only experience I have is replacing a ducted Penguin with a Penguin II. In this case, there are metal tabs welded in the corners of the roof opening for the bolts to pass through. And the bolts pass up pretty close beside the ceiling duct. So there's not much room for the bolt spacing to change before you're cutting up the ductwork. 

I remember seeing some specs on other units that showed the bolt spacing to be a lot more narrow. If you've got a non-ducted setup with the air distribution box on the ceiling, maybe its a lot more forgiving. But if you have a central duct up in the ceiling, that might make the replacement a lot less clean.

 

Cheers,

Walter

bolt hole.jpg

Edited by wamcneil
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The unit has a new board, new capacitors, and wall thermostat has been replaced.  Still short cycles so rather than keep chasing gremlins I'm just going to replace.  It  looks like the new units are starting to show up.  New part number 651815HXX1C0-0 for the 13.5k units.  Now I just have to decide whether to wait for the 15K units to become available.

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33 minutes ago, michaelivan said:

Now I just have to decide whether to wait for the 15K units to become available.

Mike, the 15K High capacity AC's are available now. I did a quick search and found a bunch from different vendors with a wide variety of prices. The link below seems to be the best deal right now for a little over $1000 for one AC/HP model. You may find it even cheaper with a more extensive Internet search.

https://www.rvpartscountry.com/Dometic-Penguin-II-W-Heat-Pump-High-Capacity-Low-Profile-Rooftop-Air-_p_40197.html

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3 hours ago, Dr4Film said:

Mike, the 15K High capacity AC's are available now. I did a quick search and found a bunch from different vendors with a wide variety of prices. The link below seems to be the best deal right now for a little over $1000 for one AC/HP model. You may find it even cheaper with a more extensive Internet search.

https://www.rvpartscountry.com/Dometic-Penguin-II-W-Heat-Pump-High-Capacity-Low-Profile-Rooftop-Air-_p_40197.html

Thanks for the heads up.  2 new units with digital control and new gaskets on the way. If anyone is interested in my one good unit let me know. I am in Central Florida.

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On 9/19/2020 at 12:27 PM, michaelivan said:

Thanks for the heads up.  2 new units with digital control and new gaskets on the way. If anyone is interested in my one good unit let me know. I am in Central Florida.

Just to give everyone an update and a heads up.  I placed an order with RV Parts Country for 2 of the new model 15K heat pumps on Saturday and received an email confirmation for the order that stated they would provide me with a tracking number as soon as the item ships. Today I received and email update stating:

Your order will be placed directly with the Dometic manufacturer. The current lead time is 3-4 weeks for the item to ship out, although this is an estimate and it may take longer.

If it hadn't been such a good price for the 2 units I would cancel and look elsewhere.  Might do that anyway since DW isn't happy not having 2 working units.

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Well that's a BIG bummer! Obviously now with that email response they most likely never stock these items but drop ship them from Dometic. However they should have stated that on their web site to be more transparent in choosing whether to purchase from them or someplace else.

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48 minutes ago, Dr4Film said:

Well that's a BIG bummer! Obviously now with that email response they most likely never stock these items but drop ship them from Dometic. However they should have stated that on their web site to be more transparent in choosing whether to purchase from them or someplace else.

When I check a few other sites they all show not available for the 15K model.  PPL has the 13.5k model in stock so I have to decide if the wait is worth it in order to get the bigger units.  I know the 13.5 units that we have now seem marginal on those days when it is 95+ outside.  Or switch over to the 15K Brisk Air models.

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On 9/21/2020 at 11:18 AM, michaelivan said:

Just to give everyone an update and a heads up.  I placed an order with RV Parts Country for 2 of the new model 15K heat pumps on Saturday and received an email confirmation for the order that stated they would provide me with a tracking number as soon as the item ships. Today I received and email update stating:

Your order will be placed directly with the Dometic manufacturer. The current lead time is 3-4 weeks for the item to ship out, although this is an estimate and it may take longer.

If it hadn't been such a good price for the 2 units I would cancel and look elsewhere.  Might do that anyway since DW isn't happy not having 2 working units.

That sounds just perfect to me as we will be heading "home" in 2-3 weeks to vote and then these spares should arrive for storage until we stay put long enough to install.

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