Using the A/C for heating

[DBBRanger]

I have never used the A/C for heating in the 5 years I have had my R25. It turns out Yellowstone at this time of the year can get quite cold - an unseasonably 35 degrees. I'm not real happy with the operation of the cold side and now not with the hot side either. Could something be wrong with my unit? It puts out a good amount of heat - like 115 degrees. Then the compressor shuts off which I can understand that it needs to cycle. However, the problem is that the compressor will not come back on until the temp gets to be about 80 degrees. With the velocity of the air coming out, that feels pretty cold. Consequently, the unit will not heat up the boat very fast - only about a degree an hour. If it stayed at 115 degrees, I'm sure it would do great. Is there a temperature or pressure sensor that could be bad? Does anyone have a service manual? What are your experiences with heating?

Anybody have any thoughts?

 

[scross]

Do you have the Wallace stove? We use that as our heater and it works great! No a/c on our RT 25 Classic. Also while underway the heater under the helm station puts out a LOT of heat - so much that we have only used it once in three years.

 

[Connerkip]

I found maintaining a more even temp was easier when I added the remote temperature sensor and positioned it at the air intake side of the a/c unit, and I keep some airflow by keeping the air handler fan on all the time at a moderate speed. Instead of the temp reading at the thermostat, which was in the cave entrance, which was affected by position and many other variables, I now have the compressor kicking on one degree less, or more, than the setting of the actual air going through my vents. It simply plugs into the controller and wire ties to wherever you want it. Doesn't cost much either.

Not sure if this may be your issue, but try monitoring the actual surrounding air temp, at the thermostat, vs. what the thermostat is reading. This may give you some clues. I

 

[knotflying]

I use the A/C reverse mode for heat while on shore power in cold weather and it works like a champ. You may want to check your thermostat settings. There are several settings to choose. There is one setting P-5 Temperature-Sensor Calibration Ambient temp Ambient plus or minus 10° F . You may want to check that setting. I would also check your vent connections and make sure you have things secure with no leaks. I have been in 38 degree temperatures and got on a cold boat and in a matter of 20 minutes or less we were toasty warm.

 

[DBBRanger]

Do you have the Wallace stove?

Yes we do and we do use it for heat, but I'm hestitant to have it on at night while sleeping since it produces carbon monoxide.

I found maintaining a more even temp was easier when I added the remote temperature sensor

I did not know that was available. My thermostat is at the entrance to the V-birth so it is exposed to direct flow out of the vents. That's my main grip about using the cool feature. Do you know where you got that remote sensor?

You may want to check your thermostat settings

I'll do that but the thermostat seems to work OK, it just doesn't get up to temp. BTW, I may have confused the issue when I said it doesn't turn on until it gets to 80 - I meant the air coming out the vent, not the ambient temperature.

Thanks for the replys.

 

[captstu]

My 2010 Ranger are 25 Air Conditioner failed when the reversing valve jammed. The local repair guy did not want to replace the reversing valve so we talked me into replacing Air Conditioner. The new air-conditioner it’s quieter and seems cool better than the old one so while I mind the money, I don’t mind the results.

I did get a reverse cycle Air Conditioner to replace the old reverse cycle Air Conditioner because in Florida reverse cycle heating is quite efficient. You don’t have to need heat in South Florida but it seemed a good idea to preserve that facility.

I now think otherwise. For $25 I purchased a small heater but usually meets the needs to keep my boat warm on an occasional cold Florida winter day. If it fails, I can throw it away and purchase another one for another $25.

According to the local air-conditioning guy , The reversing valve is the part that fails most frequently on the marina air-conditioners. So the heat turned out it cost me 2000 bucks. I don’t think I get dramatically better heat out of the reverse cycle Air Conditioner when I got out of the $25 resistance unit. For the small number of days each year that I use it I don’t think the very slight saving electricity from reverse cycle unit comes close to paying for the additional failure risk of having the reversing valve that seems To be the weak link in an otherwise reasonable Air Conditioner.

Shortly after replacing the air conditioner, the pump failed after some grass got through the screen, through the strainer, and jammed in the pump. From that $300 adventure I learned not to run the air conditioning when I’m not on board.

So now I have a $68 Air Conditioner sitting on the roof of the boat that provides calling and dehumidification when I’m not there . It also provides adequate cooling when I am in a marina at night and I just don’t want the noise of the larger Air Conditioner. It is an enough to keep the boat cool during the midday sun in South Florida, however the Boathse unit just barely achieves that most of the day.

The solution if money is not a concern is to put a non-reverse cycle unit in the boat and a small window unit on the roof.

If however I were starting from scratch I would put a 13,000 BTU per our unit RV air-conditioner through the hatch over the stove and install a heating element in that unit to provide back up eating in the winter. The installation is about 1/5 the cost of a marine air-conditioner and since it is not water cold it will not suffer the effects of salt water. Finally, the RV and it will run on inverter when the engine is running or on the generator without any hard start problems generally Associated with Marine air.

If you’re curious you can read about it on the Boat website: Shearwater-Sailing.com

 

[Connerkip]

My a/c guy ordered it from the a/c’s manufacturer.
I had the same short cycling in the v berth you mention. Cold air blowing on the Tstat, shutting off, warming up, on, etc
Wouldn't pull the humidity out with the short cycling either.
You can see the sensor mentioned in the units operating documents.

 

[Scotty Mac]

Last winter on New Years we had 28 deg and ice on the deck, revirse cycle ac was more then enough to keep warm. With both ac and heat we have a fan to move around air in the cabin across from where the air blows out. Also if you put your manual fan control from auto to say 4 or 5 and keep fan running it will keep unit from short cycling and also from freezing up in hot humid weather.
My .02

Scott Mac

 

[Todd2]

All the previous advice is good, but I need to share my experience. From day 1, while still in Kent, my A/C heater worked intermittently (hot then cool thereafter - no error codes). From then on my A/C would work similarly
(cool for 10 minutes or so, then throw the error code E1 and turn off). Well, after a year of troubleshooting I've solved the factory installation errors.
1) Turns out the cooling hose from the A/C unit discharge to the overboard discharge was severely kinked - I added a 90 degree fitting to open it up (it's better than a severe kink in the hose). I rodded all the hoses (I don't have a borescope camera to look into the hose lines).
2) The factory switched from a direct coupled self-priming pump to a magnetic coupled pump - that is NOT self priming. The issue is, it's still installed in the same location, ABOVE the water line. It will also lose it's magnetic 'coupling' whenever it would lose it's prime and water would be reintroduced into the strainer (like from the raw water pump hose I experimented with). So it appeared to have water, but it still wouldn't pump until it was turned off and restarted so the magnetic coupling would reconnect.
3) The strainer was (with a NON-self priming pump) supposed to be installed even LOWER than the pump. It was not.
I have temporarily reinstalled the culprits (for test purposes) and it now works continuously (well, so far).

At this time, I believe I have diagnosed and corrected all the factory problems with the A/C. I know this is not the OPs's issue, but I hope to save someone a LOT of time and frustration troubleshooting their system, if experiencing intermittent operation like I was (HINT: unit stops 'pissing' overboard).

Onto the next problem - water water everywhere.............................

Todd

 

[DBBRanger]

Thanks for all the good replies. Here's the status of mine so far.

In discussing the issue with Dometic, they say that when heating, the compressor should not cycle - it will only turn off when the thermostat has been satisfied. Otherwise, the over temperature safety cutout switch will stop the compressor until it cools off. So he says something is causing the higher temperatures. That can be scale in the coils or reduced air flow. He says, as the manual also says, that they recommend cleaning the coils in the unit once a year. Although the manual says to use Muriatic acid, Dometic now says not to use it because it is too aggressive. Instead use things like Barnacle Buster. So that's what I did. I set up a bucket outside the boat with a bilge pump connected to a hose that went to the hose coming off the A/C pump to the A/C unit and another hose jammed into the through hull outlet of the A/C. I circulated BB for an hour. Although the effluent got quite blackish looking, I did not feel like there was much scale to remove. Additionally, I added the remote sensor that Connerkip mentioned. Also in a major revelation - I discovered that the louvers on the return air easily pop out. I always just vacuumed the screen to clean them. However, I see there are two screens there, one of which was very dirty since it had never been cleaned. So it is possible that all my efforts were for naught other than cleaning the screens. Won't know until next year when the boat is back in the water. The other thing I learned is that the A/C unit is very heavy such that lowering the unit with the shelf inside the cabinet is a major deal - you don't want to hear that story!