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Rcnewell11 · 07-08-2013, 06:55 PM

I am having problem with my ac ducted unit in my front bedroom .when I have ac unit running it shuts off every five minutes or so and turns back on in thirty seconds .the unit is domestic penguin 13.5 unit with wall thermostat.when I have down draft door open on unit it works great but when I close down draft door to run through duct work it starts acting up .i feel air coming through bathroom duct and kitchen duct from that unit running so it is moving air alright and in living room .my back unit 15 btu works fine with down draft door open or closed. The front unit water drip pan on ac unit works great and drain away from unit to roof and down down spouts great .let me know if anybody has this problem .

jesilvas · 07-08-2013, 09:37 PM

You could have an issue with freezing due to lack of airflow.
There's tests that should be run to rule everything out.

sc3283 · 07-08-2013, 09:55 PM

sure sounds like lack of air flow through the ductwork beings it works with the "dump" open

Rob_Fla · 07-08-2013, 09:59 PM

We had problems with our Jayco Pinnacle's bedroom A/C Freezing up all the time.
There is only one duct line on the front A/C and there was very little air flow.
The Rear A/C has two duct lines one both sides so it has much better air flow.
I added a couple of vents to the duct up front and added a short duct and vent on the other side, cooling and freezing problem fixed, works good now

Rcnewell11 · 07-09-2013, 06:32 AM

Sounds like a lot of work to make work like tearing out ceiling to run duct lines and vents but might try if works.

hjsdds · 07-09-2013, 08:48 AM

Air conditioning companies and and hot air heating systems companies publish manuals, tips and design guides for air flow movements, air volume, duct sizes forward and return, plenum sizes, etc., etc to make these work reliably and efficiently. Understanding these falls under two categories, either engineering or practical experience.
I'm surprised because Jayco is an old and pretty good company, but in this instance it seems they turned over the "design" to some kid on the line or someone they hired out of the rehab. "Hey, throw in some ducting between that front AC and that hole in the ceiling we cut".

hjs

Rcnewell11 · 07-09-2013, 07:46 PM

I ran front unit today only and ran great but when I run back unit at same time when it starts quit running normal unless I open draft door and dump air in bedroom then it runs great with both ac going 50amp service .the temperature today in Indiana was about 85 degrees and high humidity .i think air is pushing in trunk line at each other and not moving much and unit is freezing up and giving me problems with not enough air flow from front unit.

Rob_Fla · 07-09-2013, 09:10 PM

Quote:

Originally Posted by Rcnewell11

Sounds like a lot of work to make work like tearing out ceiling to run duct lines and vents but might try if works.

Was not much work to do the mods to ours, took about a hour.

Such a shame as I believe Jayco is better than this, our Pinnacle has been a great unit, guess the bean counters are getting their way and pinching penny's.

Rcnewell11 · 07-10-2013, 06:20 AM

Rob_fla did u plug duct going to back of unit when u made modifications to your front unit ducts and vents or leave open to help cool back of unit .just wondering

Jimooo · 07-10-2013, 06:30 AM

Sounds like your unit is short cycling due to low refrigerant or blocked /plugged evaporator coil.

When was your coils cleaned ?

Are your fans working?

Hope this helps,

James

hjsdds · 07-10-2013, 09:26 AM

Quote:

Jimooo Sounds like your unit is short cycling due to low refrigerant or blocked /plugged evaporator coil.

When was your coils cleaned ?

Are your fans working?

Hope this helps,

James

Good advice, a lot of problems with air conditioners is solved with good coils cleaning and/or with filter replacement/cleaning. Although your problem sounds more and more like louse ducting "design (?)"

hjs

Rcnewell11 · 07-11-2013, 05:48 AM

New unit 2013 dometic low pro 13.5 clean coil and filter already checked

Rob_Fla · 07-12-2013, 05:31 AM

Quote:

Originally Posted by Rcnewell11

Rob_fla did u plug duct going to back of unit when u made modifications to your front unit ducts and vents or leave open to help cool back of unit .just wondering

We did not plug any ducts at all, was trying to get better air flow by adding registers.
Added one register on the front of the duct line where it ends towards the front closet and made a short duct on the TV side by carving out Styrofoam and lined with foil tape then added a register.
Much better air flow, works great.
I thing in the pictures of the newer Pinnacles, Jayco is now putting in two duct lines up front.

bruceisla · 07-12-2013, 05:49 AM

Quote:

Originally Posted by Rcnewell11

New unit 2013 dometic low pro 13.5 clean coil and filter already checked

It sounds like your Dometic is "short cycling". Typically, this is caused by a bleed of cold air into the warm air side. Pull the trim piece from the bottom and look into both the warm air side and up thru the "dump" side. The aluminum tape should be intact all around the baffle (the divider) and the tape should totally seal the ducts where they come into the distribution box.

If you have the newer style baffle (a heavy dense foam piece) make sure the foam seals on the edges are intact and in full contact with the sides of the roof cutout. Also check that the baffle is within the groove on the template (the heavy metal plate on the bottom).

A short cycle is less likely to occur when the dump register is open because there is no back pressure to cause a bleed to the warm air side.

Did this occur before the unit was replaced?

Was the entire unit replaced or just the topside?

It is possible that the duct design is undersized and causing the short cycle .... but unlikely.