AC will not generate heat, 250 FV
Pam
Member Posts: 73 ✭✭
We just became owners of a 2003 Rinker Fiesta Vee 250.
The AC does not seems to work properly as we cannot get it to generate heat despite proper settings in the control panel as far as we can tell. As we are in Sweden we badly need the heating to work this early in the season. The boats documentation is not complete in regards of installed equipment but my guess is that the heating works by reversing the system and not by an electric heater. The previous owner didn´t know. I this the most common setup?
The seawater runs through the system as it should and the sea water temp is 2.5 degrees Celsius above the systems minimum requirement.
Have anyone encountered the same problem?
Any ideas what to look for?
Can the revers valve be stuck?
Is the system low in freon, or whatever it runs on? How can I tell?
Where in the boat can I find the central unit? What do I need to remove in order to get to it?
The control unit looks like the one in the picture, but with red digits, so my guess is that the system is from Dometic, maby a MCS5?
Any ideas on how to solve this is much appreciated.
Kind Regards
Johan
Comments
Thanks for your quick replay raybo3.
We believe that the compressor is running, we think we can hear it over the sound of the blower.
Where do we find the compressor and the reversing valve?
We have a pretty god idea that it is behind panels at the starboard side, just aft of the head, but the question is how to reach it? What to dissemble to get it?
If the system is low on refrigerant, the exchange will freeze in heating mode, and the coils in cooling mode.
If the system is empty, the condenser will make unruly noises and get really hot.
The only way to know for certain is to put a gauge set on it, and run it in a/c mode for at least fifteen minutes to allow it to stabilize.. you'll use your gauges and determine subcooling and superheat, and in hopes of isolating issues. It's incredibly difficult to do this when its cold.. the only way to charge a system accurately in heating mode is by weight of the refrigerant, which means youre going to have to know how much it holds, including lines, coil, condenser, and exchange..
If its low or empty, it didn't just pull a Houdini on you, it went somewhere.. which means there is a leak.. you'll have to use dye to find it.. pay close attention to Schrader valves, they like to leak... I hope for your sake that is it.. it is in your best interest to hire an HVAC tech to do this for you, as buying just the tools would likely exceed the costs.. you're in Europe, and have es22 available as a suitable replacement for its expensive r22 cousin.. our epa hasn't approved it yet, but it is a direct replacement that shouldn't be mixed with r22, but after the system is evacuated can be used with no more mechanical exchanges.
Best of luck!!
LG
Boat Name: King Kong
"Boat + Water = Fun"
Dream 'Inn III -- 2008 400 Express
Thank you all so much for your suggestions.
We have downloaded the user guide and the installation guide and are going to use these as reference as we will go through the entire programing during the upcoming weekend.
If that doesn´t do the job I will make my way to the central unit and give the reversing valve some attention.
We will keep you posted on the progress.
Thanks again
Johan
Boat Name: King Kong
"Boat + Water = Fun"
an HVAC guy can do this in an hour or so, for such a small system... make sure (if the lubricant isn't already present in the refrigerant) to add lubricant.
Well, the seller states that the system is equipped with heating and it had been working before. There is no documentation.
We couldn’t tell for sure if the cooling worked properly since the surrounding temperature were about 10 degrees C ( 50 F).
// Johan
Low pressure measures the gas state temperature and pressure, which correlate with refrigerant so long as it is a matching gauge (r22, for example).. same thing with the liquid high pressure line.. at your collector/condenser coil, there is a port for the gauge on both gas line (usually the fat and insulated line) and liquid line (usually small line which is uninsulated).. between those readings and while the system is stable, and ambient temp, you determine super cooling and subheat.. that will tell you if there is a leak, a blockage in the coil/exchange, a faulty reversing valve, condition of condenser and the coil or exchange, ect... If you're down to unseen mechanical function, and past troubleshooting panel/circuit, getting a gauge on it is all you can do..
Riddle me this: when the system is in heat pump stage, and has been running for a good while, can you feel warmth on the fat insulated line? ... It should be beyond warm, and be hot to the touch instead.. at least north of 120*.. if it is ambient temperature, you're system is likely empty of refrigerant .. if it is warm, your system is low..
It's very difficult to t/s an a/c/heatpump in the cold.. all you can really do is charge it to a 50-70psi level and see what happens, or, evacuate the entire system, check for leaks, and refill BY WEIGHT.
With no wind, a blue sky and a water temp at 45F an air temp at 55F we took the boat for a quick spin on the strait between Sweden and Denmark. She runs like a dream.
Once back at the dock I spent some time entering and going through the programing of the system but stumbled on new challenges.
I could enter the program as instructed in the user guide for Dometic MCS5/15, page 15, (https://www.dometic.com/9ad940b6-54f6-4bcc-b779-1b09dbb3ac49.fodoc)and the structure of the programing in the boat is to some extent similar to the instructions but besides from that nothing looks the same.
This makes me wonder if this is a Dometic system at all or if it is an older system with different, limited, programing options. The boat is from 2003 so my guess is that the unit is from the same year or maybe the year before.
I didn´t bother to remove panels in order to inspect the unit since the programing were so odd.
Does anyone recognise this programing?
Any thoughts on this?
Thank´s
Johan
RinkerYan
Ok.Thank you
Finally some one that seems to have the same A/C unit as I have.
I believe that further down the program list there is one position were you set whether the system is equipped with an electric heater or reversing valve. Do you know this program position and its optional values?
At the moment I can´t recall if the programing went all the way from U1-U24. I just got the impression that it had fewer steps then the user guide with “P” programing have, but I might be wrong.
Do you by any chance know the make and model of the unit in your boat and do you have a user guide or at least the table that describes the different program steps?
Thanks
Johan
I absolutely agree, there is probably no electric heating but the previous owner admitted that he had been “messing around” with the programing and I believe I need to make sure he hasn’t sett U15 (P15) in the wrong mode (ELE=electric heating).
The thing that puzzles me is that, as I recall from looking at the programing, my unit only used numbers (0-9) to indicate the settings and this is ok as we look at U1 (R1). When we look at U15 (R15) on the other hand it´s expected to toggle “nor” or “ELE”. No Numbers.
So, I either made a mistake when I looked at the programing or I need to find another user guide where probably “1” and “0” will correspond to “nor” and “ELE” or the other way around.
Thank you for the link to the guide.
// Johan
Well some progress were made.
I managed to identify the correct make and model and most importantly, the right user guide: http://www.marinespecialists.com/marineairsystems/manuals/vector_compact/
Based on this I could confirm that the programing of the unit were OK
Back to the reversing valve. I removed an oval smaller panel, the one with the air intake, but there is not enough head room to view the backside of the unit. I could barely stick my arm and hand over and down the back side. I managed by the use of my cell phone camera to take some photos and I believe I have identified the solenoid and the reversing valve. The solenoid should be the black item with white and yellow cables attached.
Picture taken from above the unit . In picture; starboard is up, port is down, stern is right and b.... you will figer it out. :-)
As I can´t fit more than one hand and can´t see what I am doing I will not be able to tap it with a mallet nor remove the solenoid in order to exercise the valve manually. I think I need to remove the entire starboard side panel at the foot end of the bed in order to be able to access the backside or to unscrew and move/turn/tilt/ the unit.
Does anyone know if there are any slack on the cables/pipes/hoses/ so that I can move the unit around or should I be prepared to detach these?
Thanks// Johan
Dream 'Inn III -- 2008 400 Express
Update.
During the weekend I changed the U1 setting to ”2” (Heat Only) but it didn´t make any difference.
I then removed the entire starboard side panel and finally I could reach the valve and solenoid.
While having the A/C in operation I taped repeatedly the solenoid and valve and suddenly the noice changed. The additional sound is a bit like a gas or a liquid passing through at tight pipe or a tight bend/narrow passage/. It´s a sound reminding of an old refrigerator and as I disconnect and reconnect the yellow cable to the solenoid I now can clearly hear something moving back and forth and the new sound goes and goes with it. I therefore believe this is a step in the right direction.
I felt with my hand on the four pipes in the picture as the unit were in operation. Number 2&3 had no significant temp change. Number 1 were a bit hotter than my hand. Number 4 were really hot, could only keep my hand on it for a few seconds. The photo is taken from above on the left side. You can also se the yellow cabel leading to the solenoid furter down.
Unfortunately I still get no heat form the system even after 30 minutes of operation. I wonder if it could be that the valve opened up partially but not all the way.
What are your thoughts on this?
By the way, I discovered that the entire woodwork behind the panel were completely rotten. At least the wood placed directly on the carpet was. Underneath the white surface the wood were like coffee. So I need to change it all. I bet you can guess what the carpet looks like. God thing that this was discovered. I must say that is not a bright idea from Rinker to let the carpet go under and behind at concealing panel all the way to the starboard side and then place an A/C, drain pipes and woodwork directly on top of it. If it for whatever reason gets moist, it will never dry. Due to the tight fit of the panel I couldn´t smell the rotten wood until the panel was removed. I´ll post a picture of it in the next comment.
Maybe I am not the only one with this surprise?
Regards// Johan
it does this when there is a low coolant condition... it doesn't matter which phase the system is in- in cooling phase, it will condense on the coil, in heat, on the exchange..
your reversing valve will also freeze (as in get stuck) with a low coolant condition- the coolant has lubrication added to it.. if the coolant has escaped, which I would guess is the situation, air infiltrates the system.. air mixes with remnants of coolant and the oils added to the coolant, and makes an acid, which does what acid does and eats softer metals, seals and components (such as a reversing valve)..
the sound you described sounds as if it could be a flooded condenser.. a condenser will flood if the line is expected to have gas in it, but has liquid instead.. it's not supposed to return to liquid until it passes through the coil or exchange. If it's liquid before that, it will freeze the coil/exchange (depending on mode), hence: condensation and frozen appearance of the coil/exchange..
the water damage indicates it was freezing up, which indicates it was low on coolant.. the lack of it freezing up now indicates that it is likely empty of all coolant, now..
there is one thing not mentioned that you can give a shot.. as ridiculous as it sounds, one place people often make a mistake is by not allowing air to flow to at least the lowest rate expected by the blower....... make absolutely certain every vent is open and not blocked... a lack of air flowing through the coil/exchange can do exactly what you're describing and explaining.. this is a long shot, in my opinion, though, because of the water that was present..
Johan, I strongly recommend you get a HVAC tech out there to look at it.. they can slap a gauge-set on that thing and tell you precisely what the problem is via head-pressure, superheat and sub-cooling, as well as check out your electronic devices (the reversing valve, dryer, and electronics card NOT the thermostat).. Or, you can buy your own gauge set, do some googling on how to use it, and check it out for yourself.
I'd agree with Drew on the a/c tech checking it out at this point. At least you know what he doesn't need to check and you also found a potential problem that needed attn.
Good luck, Mike
Johan, I don't recommend it, but, in a pinch you can use a tire pressure gauge... It won't tell you much, but you can compare it to a chart and your ambient temperature to see if there is any charge in there.. I think its said that idle and at 65*f, it should be around 50psi or a little over three bar... That's idle, as in not running.. a slow leak may retain some charge, a big one empty of charge.. obviously, even a small one over time leaks to nothing in the right ambient temperature.
An update.
I had an A/C tech looking at the unit yesterday and he determined that there were absolutely no refrigerant left in the system. Since there were no signs of leakage, (=no visible oil leakage), he concluded that it leaks trough the seawater piping. According to him this is irreparable so my choice is to replace the entire unit.
The unit, Dometic (Marine Air Systems) VCP7K is no longer in production and is superseded by Dometic VTD6, product number: 205561200, running on 110V. This means that I at least can keep the water pump and the control unit /thermostat.
I´m thinking of importing the VTD6 myself from US since the Dometics dealers in Sweden needs 6 weeks for delivery.
I had issues on a prior boat and I just replaced the unit. The newer units have a nice fiberglass type bottom so you will not get any rust from the condensation, which is what caused my freon lines to corrode.
I do agree with RY, a quick pressure check would tell you. Not sure what to tell you as far as dealers go. I bought from someone local that had a great price & didn't have to pay for shipping. I know you don't have that choice.
Dream 'Inn III -- 2008 400 Express