SailNet Community banner
  • SailNet is a forum community dedicated to Sailing enthusiasts. Come join the discussion about sailing, modifications, classifieds, troubleshooting, repairs, reviews, maintenance, and more!

Issues with Heating in Annapolis, MD

5K views 38 replies 17 participants last post by  Kraden313 
#1 ·
Need some help! My husband and I live on our boat here in Port Annapolis. We live on a Hunter 410. We just moved to Annapolis from NC last October, so the issues we are having now are a first for us both. Not to mention we have only had the boat for about 3 years now. The weather here is about 18 degrees and hasn't been above freezing for the past week or so. Not to mention a little snow night before last and more expected today. We have a heating and cooling system installed on the boat which is really nice and we also use a space heater at the front just to help. Here's the problem.....as of yesterday, the back unit was not putting out heat. The thermostat read at 54 degrees; however it was set at 66. The front unit is doing the very same as of this morning. It is reading 54 degrees but is set at 66. Here are the things I have checked; the raw water strainer....which is fine and has water in it and is running....both units, which are not froze over and you can hear them running it's just not heating. What bothers me is that the water that typically comes out on the outside of the boat through the little holes (don't know what they are called) is NOT coming out! What could possibly be going on here and how can I fix this?? IT'S COLD!!!
 
#2 · (Edited)
Back-up heat filaments have gone? There *is* a back-up heat source in yer air handler, isn't there?? Or....
The "heat pump" can transfer calories from a raw water exchanger as long as it's not frozen water; but if it's an air induction type....:eek: The air temp, once too low, will not have enuff BTUs innit to pull heat out.

Avoid the HVAC "rush" and go to Lowe's and but supplemental heat units.
 
#3 · (Edited)
Sounds like you have a reverse cycle unit vs a straight electric one. Once the water temp reaches 50 degrees your system will not be able to work efficiently and pull heat out of the water. It may damage it if you keep running it. You will need to find an alternative way to heat your boat in the very cold water times.
 
#4 ·
sorry to be do dense...but this is all new to us. What is a "heat filament"? Also, if this water temp is below 55, which I'm quite sure it is, what are our options??? How are other people living aboard out here and staying warm? What I am afraid of is pipes freezing and busting. :( Do I turn the whole unit off at the Nav station....or just let it run so it doesn't freeze? Please be patient with me.....all new and still learning.
 
#5 ·
Get some more of those space heaters since your heat pumps apparently lack electrical heating elements or they aren't working. Watch your current draw on your outlets or you'll be triping breakers. I've run an extra cord into the boat to get the necessary amps to keep warm in sub zero conditions.
 
#6 · (Edited)
My best guess is that you probably have ice in the discharge hoses for the heating units. Reverse cycle heat pumps cool the discharge water when the system is heating. My guess is that this chilled water has frozen either at or inside of the thru hull. You should be able to see that discharge hose and the thru hull from inside the boat. If I had to deal with this, I would swing by the hardware store and get some "heat tape", which is tape that has a heating element in it that is used to keep pipes from freezing in an unconditioned (attic or crawlspace) space in a home. You should be able to wrap the hose with the heat tape and thaw it out and keep it thawed.

My other concern is that if that hose has frozen that it does not have a tear and that you have not burned out your circulator pump trying to move water against a dead head. When the hose thaws you will need to keep an eye on it to make sure that it is not leaking. You may also want to take the discharge hose off the circulator pump and run it a second to see if it is working.

I walked over and checked; the TruValue Hardware Store on the corner of Forest Drive and Bayridge Avenue carries heater tape in several lengths. (If you pick it up at the TruValue, please feel free to stop into the architectural firm in that complex and say hello.)

Water media heat pumps actually work down to much lower temperatures than air cooled (heated) units so I do not think that this is an issue of the water temperature.

Good Luck,
Jeff
 
#7 ·
THANKS! very helpful responses.....I am definitely going to get another space heater for now...it's about 50 degrees in here! Also, I will get some heat tape....I am hoping and thinking that might do the trick.....fingers crossed there is no damage to the system itself. thanks again for responses!
 
#8 ·
The lack of discharge water supports Jeff's conclusion of a blockage. I'd get a couple of ceramic heaters to keep heat in the boat while you're working on the system and prevent further freezing. I'm also concerned about the pump, I'd shut the system down until you clear the obstruction and determine that the pump is working. But you'll need to work quickly in these temps.
 
#9 ·
Hm, I'll partially agree with Jeff here.

The reverse cycle will function, but it's very inefficent at these water temperatures and may place undue wear and tear on the system by running constantly. Cross your fingers that next week's warming trend boosts the water temperature closer to 40F degrees again.

Yes, you can you buy additional space heaters but please ensure that your boat's electrical system can handle the load, or you're courting an electrical meltdown!

Example: If you have 30 amp shore power, you should not continuously run electrical loads that exceed 80% of that. If you have 50 amp shore power, or two 30 amp shore power cables, then you have considerably more wiggle room.

Future planning:

Annapolis is on "the fringe". Each winter, the jetstream oscillates up and down across the area, giving us unseasonably warm temps at times, and very cold temps at other times.

If you're going to remain in the area, I advise you to investigate installing a diesel heater on your boat. It will draw from your main diesel tank, and easily heat your entire boat to very toasty temperatures, with very little electrical load.
 
#10 ·
Kraden get hold of someone that knows just what you have for systems in your boat. if they are reverse cycle (heat pumps) They will work at any temp but the water has to liquid. If the incoming water is slow or stopped the heat exchanger (looks like a coil of insulated tubing) can burst from ice pressure within. In addition to space heaters you will need some of that heat blowing on the unit itself. Hopefully next week will be somewhat "warmer" then this week.
 
  • Like
Reactions: Kraden313
#11 · (Edited)
Knowing specifically what system you have is the first step to troubleshooting.

We have a Mermaid 16000btu reverse cycle unit and we used it right up to new years day. The water was in the mid 40s and it continued to pump out warm air and maintain 65° in our cabin although it cycled every 10 minuets. It does not have a supplemental heating coil. We also have an ITU Hurricane II diesel hydronic furnace for the cold days like we are having now.

The other thing you need to properly troubleshoot is an infrared thermometer.

But you must ensure that those through-hulls are not frozen. That can be very dangerous. The fittings can rupture from the expanding ice in them and cause leaks when your boat heels and they submerge.

BTW, this could also simply be a pump relay that is not functioning. We had similar issues with our reverse cycle relay. A good bump would activate it until I could replace it.
 
#12 ·
Hey Kraden, stop by our boat for a cup of hot cocoa and a tour - it's probably about 70 in here. We have diesel heat plus a couple of electric space heaters. We'd be glad to loan you a space heater until you get sorted. We could also come by this afternoon and help you verify what type of heat you currently have.
 
#13 ·
One thing we did when we lived on our boat during winter in Annapolis was to wire two electrical outlets from the 30A circuit that is decicated to the Aircondition.

One outlet in the aft cabin, one in the salon.

That way we utiilized all 30A shorepower coming in to the 30A aircon circuit to run two large oil filled heaters, while still having the 30A on the "house circuit" available to run other electricals (TV, toaster, coffe maker etc) on the boat.

You should be able to do the same thing since your boat has two 30A circuits and dual shore power inlets.

If you cannot do the install yourself, a marine electricain (or general handyman) should be able to do this inexpensively.

The two oil heaters kept our boat warm during the entire winter, we never saw less than 66F in the boat regardless of outside temp.

This modification together with a dehumidifier, a froli systemunder the matress and electric blanket was the things that made our winter relatively comfortable.

Other than that, moving into a house might be the best solution ;-)
 
#14 ·
My understanding of heat pump/ac type units that lack additional resistive heating elements is the most efficent units can only heat or cool approximately 30 degrees from ambient.

So on a 100 degree day, ac is only going to get you down to about 70 degrees. Conversely, if its 20 outside, about 50 is all the "heat" you can expect from a heat pump unit. You are gonna need some alternate means of heating your boat when the temps get below about 35 degrees.

Home heat pump units have a "second stage" to take over when the heat pump alone is not enough, but marine units lack this feature. The second stage is usually electric resistive elements.
 
#15 ·
Bubblehead thanks for the information. The more I read these responses and the more people that I talk to it actually just sounds like the water is just too cold and our unit just can't keep up. Makes sense I guess. I believe we actually have a 50 and a 30 amp Shore Power. I have a space heater running now....but it's just not doing much. Husband will be home shortly and is going to stop by Lowes and pick up a different kind of heater. Sooooo much to learn on this boat. But it's fun....and challenging. Thank goodness for warmer temps next week. WingNWing......would love to chat with you more about this since you are right here. I think you have my number..if not let me know and I can send it to you through gmail. THANKS!!!!!!! :)
 
#17 ·
it actually just sounds like the water is just too cold and our unit just can't keep up.
That may be in part be true but it is not the problem that you are having. If that were the cause of your problem, the unit would be running continuously and you would have a continuous flow of water at your through hulls. The clue to what is wrong is that you do not have water flowing.

But even if your system were running it may not be able to keep up since boats are insulated and water to fiberglass is a pretty efficient heat exchanger. But even so, a water media heat pump should work reasonably well even when the water is close to freezing.

You should shut that system down until you determine whether the circulator pump is working right, and whether you have a burst hose or through hull. You also should check your bilge for rising water.
 
#16 ·
Also, one other thing...I have gotten a few "Private Messages" about this and apparently since I just signed up today, I am unable to reply to those messages. I can actually see part of the message on my iPhone, but again, cannot reply until I have been a member for at least 7 days.....well that's the message I am getting anyways when I try and open the message. I just don't want you to think I am ignoring you. Thanks again :)
 
#18 ·
Actually some marine units do have resistive elements as an option. I can get one for mine if I like.

Some other notes. A marine unit typically uses water as it's medium so the air temp has very little to do with how much heating or cooling one can generate. It does affect how much the unit cycles though.
 
#20 ·
Jeff that is correct that the water was not coming out of the thru hulls last night or early this morning. And when you mentioned it might possibly be frozen on the inside, that was my initial thought. I actually turned the unit off this morning after I made my initial post and got a few replies. I kept it off for a few hours and around noon I turned it back on and went outside to see if we had water flow. We actually did start to have flow coming out of the back and front hulls again. So I left it on, anxiously thinking we were getting ready to have some heat again; however, the temp only got to 50 and would not go any higher. So I just turned it off again and we are looking for some oil heaters to use in the meantime. Next week when we have some warmer temperatures it will be interesting to get the units turned back on and see what happens. Thanks for the heads up on checking the bilge.....I didn't even think about that earlier, and I just checked it and all is good....no water. :) Thanks again for all your thoughts and posts. Very much appreciated for sure.
 
#21 ·
Larger type water supplied heat pumps have a water flow valve that modulates the flow according to the High pressure needs of the compressor. I doubt small marine units have them.

People forget that the heat exchanger while it's a condenser in the cooling cycle.. in the heating cycle that same coil becomes the evaporator and the water going through it gets 10-15 degrees Colder then when it enters! Easy to freeze up!
 
  • Like
Reactions: wingNwing
#23 ·
Chef2sail....that is very good information as well and very much appreciated!! Thank you for looking that up and sending it our way. We have quite a few things we need to address for sure and figure out the most efficient and safe way to stay warm this winter. We really do appreciate you....and everyone else....responding and helping out. I love these forums!
 
#26 ·
Also consider that your unit may be putting out heat but just not enough. That is where the infrared thermometer helps. You can shoot the output right at the vent. An undercharged system could also act this way and not produce much heat.

Find out if you are getting any heat at all. When it switches on you should hear the reverse cycle relay trip shortly after start-up. Give it a good five minutes and then check the temp of the air coming out the register.
 
#28 ·
Hi Chef.....first thing is we just turned the whole unit off as it wasn't doing any good. Praying we didn't do any damage to it. We will try it out when weather/water gets a little warmer. We got two oil heaters that are doing a fairly good job of heating the boat. Our thermometer is reading a pretty steady temp anywhere from 65 to 72 degrees in here.....depends on how many times we open the hatch to let the dog out :) We also invested in a nice heating blanket for our bed. NICEEEEE!!! :D What's funny is before we moved up here from NC, I had connected with WingNWing through another forum and we chatted quite a bit about the whole move, pros and cons of living aboard during the winter, etc, and she seriously hit the nail on the head about various issues we might possibly encounter during this time. She is so smart!!! :) She came over here Friday and we had a good chat. She's awesome! To be honest with you, I'm not quite sure this boat has been in this cold of water. I have only been living aboard for a year. My soon-to-be-husband has been living on here for 3 years. The previous owners kept this girl way down South in warm waters. So perhaps she is just having some temperature shock....like me! All in all we are doing much better than we were on Friday. I love these forums because I feel like I learn so much from all the gracious posts! THANKS for checking on us Chef!
 
#30 ·
Denise030

I think you have hit the nail on the head. I just opened this thread and thought of freeze up immediately.

Kraden
I hope the heat exchanger didn't freeze up . (most likely it didn't) Might to be a good idea to find a small fan to pump some heat below or around your heat/cool units.

Best of luck
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top