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Sky_Boss · 01-17-2015, 04:41 PM

OK...this one has be a tad stymied.

Talking about Dometic Penquin 15M AC/Heat Pump

The front AC was replaced last March and then again in June. It appears there were a batch of bad ones. Anyway...

A couple days ago I noticed the front unit set to heat pump was running continuously. I got up and notice that the fan was running but it was basically recirculating the ambient coach air. This was also true in the AC mode.

Just to verify things I got my IR gun out and pretty much it shows that it isn't doing anything but moving the air. I then used my power monitor display to see if it was drawing the typical current of around 14-15 amps. Yep...it is drawing the appropriate current. That has me scratching my head some more so I got on the roof to see if there was anything obvious such as if for some reason the foam that channels the air had blown out. NOPE...it looks normal.

So...I have a unit that is drawing the appropriate current but not doing a darn thing except blowing lukewarm air. Any thoughts?

BTW...if this unit had a bad reverser valve or the control board fails to activate it, the default is AC mode. Nope...it don't get cold.

TQ60 · 01-17-2015, 07:22 PM

Is the compressor running?

What is hot and cold via ir gun?

The ir should indicate where the coolant is going via hot someplace and cold someplace else

Sky_Boss · 01-17-2015, 09:03 PM

Quote:

Originally Posted by TQ60

Is the compressor running?

What is hot and cold via ir gun?

The ir should indicate where the coolant is going via hot someplace and cold someplace else

According to the amp draw the compressor is running. Feeling the registers affected by hand and confirming no real temp change via the IR gun...no change.

I even got up on the roof to see if there were any obvious air leaks. None found.

Very curious.

TQ60 · 01-17-2015, 09:08 PM

I would bet on the valve but you need to scan it all on the roof with the ir.

Sky_Boss · 01-17-2015, 10:02 PM

Quote:

Originally Posted by TQ60

I would bet on the valve but you need to scan it all on the roof with the ir.

I have been there before with the other unit. LOL It would be strange that the valve stuck in a closed both ways if it could. Can it?

Like I said...failure of the control board will allow the reverser valve to default to AC. Could a total loss of refrigerant do this without increasing the amps used?

I'm not versed enough to use my IR gun to know what to look for up there. I would do it if I was smarter about this.

TQ60 · 01-18-2015, 08:52 AM

We never doubt any possibilities...

Anyway it is simple.

If your ir gun has a laser spotter even better.

Pull covers off and have helper below.

Compressor is what looks like motor and the 2 coils are evap and condenser and since heat pump they trade places.

Evap is the cold one and condenser is the warm one.

You replaced the selenoid already and that is what makes them swap.

A bad stuck internal part may give you this issue.

So scan every part and tube first just to get a reading then place hand on compressor someplace SAFE...away from wires.

Ask helper to turn it on heat and after a bit the compressor should start and you will feel it.

Helper can confirm load on your panel you mentioned before.

Quickly scan the tubing in and out of the compressor often as well as around the valve.

The output side will be warmer than input side.

If valve is stuck all tubes will stay same as when not running.

If working they will change....warmer and cooler maybe.

If stuck gently tap it with handle of screwdriver and have helper switch modes from heat to cool and repeat.

Also check voltage on selenoid coil.

Report what you discover, we have 13.5 versions but work fine but there may be others who have more experience troubleshooting these and may be able to work with what you report.

brunsje · 01-18-2015, 09:21 AM

It should be under warranty.

Call the Dometic hotline and seek their assistance.

JohnnyB

Sky_Boss · 01-18-2015, 09:39 AM

Quote:

Originally Posted by brunsje

It should be under warranty.

Call the Dometic hotline and seek their assistance.

JohnnyB

That will be the ultimate answer. LOL

Sky_Boss · 01-18-2015, 10:05 AM

Quote:

Originally Posted by TQ60

We never doubt any possibilities...

...

Tony...thanks very much for your thoughts. I will report back on what the tech finds out.

I did get on the roof and felt around on the exposed tubing and didn't find much of a temp change...I could touch much of what appeared to be in and out of the compressor without getting burned.

Most of the tubing was only warm to a quick touch. If I knew what I was looking for I would have used my IR gun.

The tech that did the work last year is very good to work with and let me observe all of his work. I think I will have him give me a quick guide on where best to look for concerning what you have spelled out. I do much better with "hands on" OJT.

TQ60 · 01-18-2015, 10:39 AM

Some folks do not want observers and others do not mind at all.

I enjoy company of an observer/customer as I often take the observer role with vendors to keep them in line and learn the equipment.

To score "bonus points" print out a copy of the manual and have it in a binder.

When on the roof have your voltmeter ir gun and binder handy.

Read manual 3 times so you can ask good questions and have a learning conversation.

Take notes in your binder.

Ask about steps YOU can do ahead of time to provide good information for HIM as that allows him to be troubleshooting in his head before he arrives.

He may show you how to use your tools to troubleshoot it too.

Have your ladder ready and snacks as everybody works for food...

If cold have a portable heater to make it comfortable.

Sky_Boss · 01-19-2015, 01:36 PM

Tech just got done looking at it.

Compressor gets hot, evaporator gets "warm". Amp draw at the unit was only about 8A with 11-13 being the more normal range. This was all true in either the AC or heat pump mode.

This is the 3rd unit in 6 months that my service tech has seen go belly up. One only lasted 2 weeks.

Dometic tech support is being contacted to see if they can have any tricks up their sleeves. If not...another new unit.

TQ60 · 01-19-2015, 01:43 PM

If evap is getting hot and it is toward cabin then it is in heat mode and acting as condenser with evap outside.

By function anyway...

It seems valves doing what they are supposed to do and with low current then valve may be leaking or charge low.

If multiple bad ones I suggest contacting dometic with your story and ask them to perform root csuse study on your old one that will be sent back as warranty will run out sometime and will be an issue.

There are many of these in use so it could be a bad batch of something got into the factory.

Provide as much documentation as you can and start at their web page.

We got great support in the past on 1989 vintage units that way.

Sky_Boss · 01-31-2015, 10:41 AM

Just had the replacement, to the replacement, to the replacement AC installed. Yes, that means 3 different units in less than a year. LOL

My tech now knows of 4 replacement units like mine that had to be replaced at least once because of the reverser valve issues. One unit failed 2 weeks after installation.

We did also find that the previous installer forgot to put down a foam strip below the unit to direct the air properly for the most efficiency but that wasn't the root cause of my failure. Hope that helps for real.

Earlier I both called and emailed Dometic about my situation and asked about how that affected my warranty dates. Dometic gave me 2 answers. On the phone they told me the 2 year warranty was renewed with each replacement but an email I got later said the warranty date was based on the first unit.

This was the email response

Hi good morning .I apologize that your having issues with your replacement AC unit . We appreciate your offer to use your AC unit as a case study however we run warranty reports and constantly test our products. Dometic AC units have one of the finest warranties offered in the industry today. Our 2-year limited warranty covers defects in material, workmanship, labor, and freight. In addition to this, Dometic offers extended warranties as an opportunity for our customers to protect their investment against unusual failures, as in this case. When we replace a part or complete product the warranty does not start over. The warranty date would go by the original date of purchase.

We appreciate this opportunity to address your situation and hope all of your future travels are trouble free. Please do not hesitate to contact us at any time to order parts or for further assistance.

Thank You
Rhonda
Customer Support Center
Dometic Corporation
800-544-4881

flaggship1 · 01-31-2015, 11:16 AM

Did I read that right???

Dear Don. Thanks but no thanks for the opportunity to perform forensic root cause failure analysis on your unit. There is no need for that because we replace this stuff all the time and know full well which parts go kaput in 2 weeks, three months and 1 year against our 2 year warranty which we run from as fast as we can. There is no reset on the warranty when parts fail but we will be happy to sell you more warranty which we will also run from. ???

Good to know! What's that model again...

Glad your up and running. Calling Vegas now for a line on it.