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Front A/C-heat pump not blowing cold or hot


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Now that I'm in the camping mode and things always seem to run in threes....

My front A/C was not blowing cold today, and to check if is just not cooling of not heating or cooling I tried the heat pump..... No Joy on either heat or cool.

That leaves me with the idea either I have an inop compressor or nothing to compress.. (freon).

Of course, this is an old unit, has been working fine until today, but if it is freon or compressor, it is beyond economic repair (IMO)

So, any suggestions on fixing or replacing??

I will climb up on the roof tomorrow and pull the cover to take a look, maybe I can hear if the compressor is running or not...

Thanks,

Ken

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Compressors rarely fail.  Check the capacitors and PTCR.  Unless the capacitor is bulging or leaking a meter is necessary.  The PTCR usually stinks of burnt electrical when bad and frequently is physically disintegrated.  It is normally on the capacitor terminal.

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If you can't tell whether the compressor kicks in while listening to it from inside or watching the current increase, put a hand on it while on the roof and you will know. Mine always turns the fan on first, then the reversing valve clicks (if in cooling mode), then the compressor starts. It does not have a low pressure switch so it should start regardless. If not, you likely have electrical issue, capacitor, board, wiring. Personally, I fix my units, refilled 2 of the units after fixing the leaks. One self-inflicted,  the other a pinhole in a sharp bend. For me, the cost is about $4 total, for the solder-in port.  I put the port on what would be considered the high side because that's what's convenient and charge it with R22 in heat mode. Most consider it not cost effective because they have to pay someone to do it, I don't. 

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I like improvising myself and the challenge that oftentimes comes with it.  It's a benefit which comes with the RV hobby. These are complicated machines and at times one wonders why they don't come with a maintenance man included when purchased. As to replacing a compressor those who don't have a vacuum pump can purge a small system with freon and argon from a mig welding tank can be used as an inert gas during the soldering process. Just guessing but I would imagine a new compressor could be had for $150.00 on ebay. The satisfaction derived  from doing it yourself is priceless. 

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I love reading some of these stories, i mean i was a mechanic for 50 ish years, an i will tackel a big job when im in a federal lock down, but sooner or later ya gotta crack open the change purse an give yourself time to enjoy some free time. When i cleaned an painted the roof on my rig it kept me from goin bat s**t crazy, or replaced the entire cooling system on my DP in 100 deg heat, it was challanging, and i gleened ALOT of personal satisfaction in knowing the job was done right! But replacing a compressor on a roof mount unit! No… there are some things even this ole magiver wont tackel, i have learned life is way to short to embrace every job, could i do it? You bet! There is not much i am not qualified to handle. An granted i dont know everyones position in this life, however i know for me if i dont learn to “pace” myself i can work from sun up to sunset 7 days A WEEK an still have shit to do till the end of time, all the while living my life vicariously thru someone elses adventures. 
 If time is the issue i might buy a new unit an enlist the help of a quality groud crew to support me while i replaced the entire thing, but if time WAS NOT AN ISSUE i would be roaming thru the yellow pages lookin for a mobile tech, one that doesnt mind me drinking a beer while i watch him work. Ken, i say check the fuses, smack the side of it a couple times ( like we did years ago with tv’s when the verticle hold kept rolling) if it dont start dial 1-800 give a s**t to get some there to replace it. 
Sorry everyone for my ole cranky ass gettin up on the soapbox an preachin but sometimes, ya jus gotta speak your mind. 

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This morning with the advice given here, Ivan, Jim, Gary, Gary... I let the machine talk to me with my ears tuned in... It is doing all the things Ivan said it should, so freon could be the issue... I'm on the road so I do not have access to the equipment I have at home (torch/silver solder, vac pump).  For now, I'll see if I can get my wife to tough it out with just one a/c...  🙂   She wanted me to just have a new one installed (at camping world (oh God!).

Ken

 

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19 hours ago, Ivan K said:

I put the port on what would be considered the high side because that's what's convenient and charge it with R22 in heat mode. 

I'm not following that logic.  The compressor doesn't do anything different in heat or cool.  The high side is always the high side.  Are you charging it after the reversing valve?  I can see that working but never considered it before.

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Ok Rik and others here... Later this morning, with my new knowledge of how things are supposed to work, (fan- rev valve solenoid- compressor) and cool morning air,

I got up on the roof and pulled the cover.

It was dirty, the foam was slightly out of place, and some wires had insulation in rough shape. with the cover off, I had the wife turn it on while I observed... fan, solenoid, compressor all ran (in that sequence).  The compressor did get warm to the touch after a while, but the condensor never got warm, the high side never got hot, the evaporator never got cool.... I did not see any clear signs of a freon leak (oily residue) but it sure acts like low freon, unless there is something else that I do not know about.  I understand and I'm familiar with 'straight Air Cond', but have no experience with reverse-cycle 'heat pumps' so if there is some other sensor or control that can cause these symptoms I would like to hear about it.

Thanks for listening!

Ken

P.S. my cell phone (hot-spot internet connection) fell out of my pocket on to the gravel surface while getting things in/out of my basement compartments and now I only have internet while at McDonalds or some where..!!  "home" button is inop.  If I get a call I can answer it, but I can do nothing else.... no "Home page"  

Edited by Cubflyer
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1 hour ago, Hypoxia said:

I'm not following that logic.  The compressor doesn't do anything different in heat or cool.  The high side is always the high side.  Are you charging it after the reversing valve?  I can see that working but never considered it before.

Exactly. On the long line along driver side. Much more cumbersome to do it at the short compressor lines. Only possible with heat pump turned on, of course. 23.6oz R22 in my case.

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Ken, I also did not have an oily spot because the pinhole was at high point where the vertical line from top of compressor makes a very sharp turn down. And I did not look for it until months later since we were boondocking with broken generator. Only was detectable under pressure. I could not believe they bent the line so sharp, like if it was meant to create a weak spot. I bet it was... 

BTW, the reversing valve changes freon flow so that your evaporator essentially becomes a hot condenser and vice versa.

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Allright, SO IF the high pressure side IS NOT GETTING HOT! Lets look at this, either NO freon, or a pressure valve is stuck! So UNLESS we can have a set of gauges on it WE REALLY JUST DONT KNOW!!! So, my feeling is if it was working yesterday “ok” an today NOTHING, if unless we could see a spray mark showing where all the freon shot out of, what would be your next conclusion….

I have not had these pumps appart, so I dont know them, can a pump run an not build pressure? Or can a heat pump valve go neutral an allow flow to go in a non pressurised position. This is tooooo much to concider for “what if” Oh yeah an how old is this unit??? Use the “KISS” methode!!!

Work on a price for a new unit, install it, connect it, run it an crack a beer while its getting cold inside.🍻😳👍

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Rickadoo is right about needing gauges which will also require putting at least a low side saddle port.  Then to re-charge you need a vacuum pump and refrigerant, probably R22.  If your local auto parts store has loaner tools they may have those but I don't know if a small can of R22 is available.  Perhaps a local A/C repair guy would charge it.

Before I went down that path I would want to check the values of the capacitors with a meter and the PTCR.  If they are not within tolerance you will end up chasing your tail.

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  • 3 weeks later...

Since I have returned to my home base last week, I have put a temporary tap on the low pressure tube, found no pressure (Freon), put some nitrogen pressure on the system and found a leak in a tube with soapy water.    This afternoon my A/C service friend came by and we (he) put a permanent tap on and soldered up the area that was making bubbles.  It is now setting with nitrogen pressure to confirm the "fix".  If the pressure holds, he will service it with R22, I will clean all the coils, put new seals everywhere. and reassemble the package (It's currently off the roof)..... if not holding pressure I will be buying a new unit....  finger crossed...

 

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Posted (edited)

Things worked out great! Pressure held, pulled a vacuum, let it set for days.  Meanwhile I added a brace to stop the stress on the area of the tubing that cracked.  Insulated and sealed up the area of the evaporator coil and cleaned all coils.  I "boxed in" the condenser coil area so that the cover is no longer needed to form that plenum.  Placed the unit back up on the roof and connected the controls, serviced the unit with R22 and it is now blowing cold air again! (Happy Me!)

Now I will complete the repair by insulating and sealing up the air distribution system.  I'm planning to fabricate a spacer to place between the plastic grill and the base plate to create a gap to eliminate the electric junction box from clogging the filter. (a problem with both units so I will make two..) 

P.S. Rik W.... I did crack a beer with my a/c guy buddy with cold air blowing.... and about $1500 still in my pocket...☺️🍻

https://photos.google.com/search/_tra_/photo/AF1QipOI3pgGabJbUESBdEa7Mq1VD_aVFQPlJLX312gv

 

aacbrace.jpg

Edited by Cubflyer
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Congratulations. Sounds like you had a lot of fun. I've been charging my R-12 and R-22 systems with purified propane for a number of years. Much cheaper and lower head pressures as a benefit. Interesting politics behind as to why propane is largely banned as a refrigerant in the USA and not other countries.  Has to something to due with Dupont, expiring patents, and of course, campaign money. 

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8 hours ago, Rikadoo said:

appears i have underestamated the power of repairing for the sake of repairing old stuff. My bad

It’s not as simple as just putting a new unit on the roof …you have to replace all of units plus a new thermostat. Karma may work on a 98 Jeep.

i’ve been using propane ever since R12 went away and I can see, in a car in an accident, having propane fan the flames might not be a good thing.

Edited by Ivylog
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I still have a couple of cases of R12 cans gathering dust.  Many years ago a Mexican friend had an explosion under the hood while driving.  We figured they had charged it with propane.

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2 hours ago, Ivylog said:

It’s not as simple as just putting a new unit on the roof …you have to replace all of units plus a new thermostat. Karma may work on a 98 Jeep.

So true!  Not only do you need to buy a new 'top unit' but it will not 'play' with other (old) unit or thermostat without an 'adapter board' (@ $200 and no stock).   

At this point (in my experience) I think if I really HAD to replace the unit, I would put a 'stand alone' unit up there..... and K.I.S.S. it.

 

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